@article {918, title = {De novo variants in SNAP25 cause an early-onset developmental and epileptic encephalopathy.}, journal = {Genet Med}, volume = {23}, year = {2021}, month = {2021 04}, pages = {653-660}, abstract = {

PURPOSE: This study aims to provide a comprehensive description of the phenotypic and genotypic spectrum of SNAP25 developmental and epileptic encephalopathy (SNAP25-DEE) by reviewing newly identified and previously reported individuals.

METHODS: Individuals harboring heterozygous missense or loss-of-function variants in SNAP25 were assembled through collaboration with international colleagues, matchmaking platforms, and literature review. For each individual, detailed phenotyping, classification, and structural modeling of the identified variant were performed.

RESULTS: The cohort comprises 23 individuals with pathogenic or likely pathogenic de novo variants in SNAP25. Intellectual disability and early-onset epilepsy were identified as the core symptoms of SNAP25-DEE, with recurrent findings of movement disorders, cerebral visual impairment, and brain atrophy. Structural modeling for all variants predicted possible functional defects concerning SNAP25 or impaired interaction with other components of the SNARE complex.

CONCLUSION: We provide a comprehensive description of SNAP25-DEE with intellectual disability and early-onset epilepsy mostly occurring before the age of two years. These core symptoms and additional recurrent phenotypes show an overlap to genes encoding other components or associated proteins of the SNARE complex such as STX1B, STXBP1, or VAMP2. Thus, these findings advance the concept of a group of neurodevelopmental disorders that may be termed "SNAREopathies."

}, keywords = {Brain Diseases, Child, Preschool, Epilepsy, Humans, Intellectual Disability, Neurodevelopmental Disorders, Phenotype, Synaptosomal-Associated Protein 25}, issn = {1530-0366}, doi = {10.1038/s41436-020-01020-w}, author = {Kl{\"o}ckner, Chiara and Sticht, Heinrich and Zacher, Pia and Popp, Bernt and Babcock, Holly E and Bakker, Dewi P and Barwick, Katy and Bonfert, Michaela V and B{\"o}nnemann, Carsten G and Brilstra, Eva H and Chung, Wendy K and Clarke, Angus J and Devine, Patrick and Donkervoort, Sandra and Fraser, Jamie L and Friedman, Jennifer and Gates, Alyssa and Ghoumid, Jamal and Hobson, Emma and Horvath, Gabriella and Keller-Ramey, Jennifer and Keren, Boris and Kurian, Manju A and Lee, Virgina and Leppig, Kathleen A and Lundgren, Johan and McDonald, Marie T and McLaughlin, Heather M and McTague, Amy and Mefford, Heather C and Mignot, Cyril and Mikati, Mohamad A and Nava, Caroline and Raymond, F Lucy and Sampson, Julian R and Sanchis-Juan, Alba and Shashi, Vandana and Shieh, Joseph T C and Shinawi, Marwan and Slavotinek, Anne and St{\"o}dberg, Tommy and Stong, Nicholas and Sullivan, Jennifer A and Taylor, Ashley C and Toler, Tomi L and van den Boogaard, Marie-Jos{\'e} and van der Crabben, Saskia N and van Gassen, Koen L I and van Jaarsveld, Richard H and Van Ziffle, Jessica and Wadley, Alexandrea F and Wagner, Matias and Wigby, Kristen and Wortmann, Saskia B and Zarate, Yuri A and M{\o}ller, Rikke S and Lemke, Johannes R and Platzer, Konrad} } @article {999, title = {DLG4-related synaptopathy: a new rare brain disorder.}, journal = {Genet Med}, volume = {23}, year = {2021}, month = {2021 05}, pages = {888-899}, abstract = {

PURPOSE: Postsynaptic density protein-95 (PSD-95), encoded by DLG4, regulates excitatory synaptic function in the brain. Here we present the clinical and genetic features of 53 patients (42 previously unpublished) with DLG4 variants.

METHODS: The clinical and genetic information were~collected through GeneMatcher collaboration. All the individuals were investigated by local clinicians and the gene variants were identified by clinical exome/genome sequencing.

RESULTS: The clinical picture was predominated by early onset global developmental delay, intellectual disability, autism spectrum disorder, and attention deficit-hyperactivity disorder, all of which point to a brain disorder. Marfanoid habitus, which was previously suggested to be a characteristic feature of DLG4-related phenotypes, was found in only nine individuals and despite some overlapping features, a distinct facial dysmorphism could not~be established. Of the 45 different DLG4 variants, 39 were predicted to lead to loss of protein function and the majority occurred de novo (four with unknown origin). The six missense variants identified were suggested to lead to structural or functional changes by protein modeling studies.

CONCLUSION: The present study shows that clinical manifestations associated with DLG4 overlap with those found in other neurodevelopmental disorders of synaptic dysfunction; thus, we designate this group of disorders as DLG4-related synaptopathy.

}, keywords = {Autism Spectrum Disorder, Brain, Brain Diseases, Disks Large Homolog 4 Protein, Humans, Intellectual Disability, Neurodevelopmental Disorders, Phenotype}, issn = {1530-0366}, doi = {10.1038/s41436-020-01075-9}, author = {Rodr{\'\i}guez-Palmero, Agust{\'\i} and Boerrigter, Melissa Maria and G{\'o}mez-Andr{\'e}s, David and Aldinger, Kimberly A and Marcos-Alcalde, {\'I}{\~n}igo and Popp, Bernt and Everman, David B and Lovgren, Alysia Kern and Arpin, Stephanie and Bahrambeigi, Vahid and Beunders, Gea and Bisgaard, Anne-Marie and Bjerregaard, V A and Bruel, Ange-Line and Challman, Thomas D and Cogn{\'e}, Benjamin and Coubes, Christine and de Man, Stella A and Denomm{\'e}-Pichon, Anne-Sophie and Dye, Thomas J and Elmslie, Frances and Feuk, Lars and Garcia-Minaur, Sixto and Gertler, Tracy and Giorgio, Elisa and Gruchy, Nicolas and Haack, Tobias B and Haldeman-Englert, Chad R and Haukanes, Bj{\o}rn Ivar and Hoyer, Juliane and Hurst, Anna C E and Isidor, Bertrand and Soller, Maria Johansson and Kushary, Sulagna and Kvarnung, Malin and Landau, Yuval E and Leppig, Kathleen A and Lindstrand, Anna and Kleinendorst, Lotte and MacKenzie, Alex and Mandrile, Giorgia and Mendelsohn, Bryce A and Moghadasi, Setareh and Morton, Jenny E and Moutton, S{\'e}bastien and M{\"u}ller, Amelie J and O{\textquoteright}Leary, Melanie and Pacio-Miguez, Marta and Palomares-Bralo, Maria and Parikh, Sumit and Pfundt, Rolph and Pode-Shakked, Ben and Rauch, Anita and Repnikova, Elena and Revah-Politi, Anya and Ross, Meredith J and Ruivenkamp, Claudia A L and Sarrazin, Elisabeth and Savatt, Juliann M and Schluter, Agatha and Sch{\"o}newolf-Greulich, Bitten and Shad, Zohra and Shaw-Smith, Charles and Shieh, Joseph T and Shohat, Motti and Spranger, Stephanie and Thiese, Heidi and Mau-Them, Frederic Tran and van Bon, Bregje and van de Burgt, Ineke and van de Laar, Ingrid M B H and van Drie, Esm{\'e}e and van Haelst, Mieke M and van Ravenswaaij-Arts, Conny M and Verdura, Edgard and Vitobello, Antonio and Waldm{\"u}ller, Stephan and Whiting, Sharon and Zweier, Christiane and Prada, Carlos E and de Vries, Bert B A and Dobyns, William B and Reiter, Simone F and G{\'o}mez-Puertas, Paulino and Pujol, Aurora and T{\"u}mer, Zeynep} } @article {1008, title = {SPEN haploinsufficiency causes a neurodevelopmental disorder overlapping proximal 1p36 deletion syndrome with an episignature of X chromosomes in females.}, journal = {Am J Hum Genet}, volume = {108}, year = {2021}, month = {2021 03 04}, pages = {502-516}, abstract = {

Deletion 1p36 (del1p36) syndrome is the most common human disorder resulting from a terminal autosomal deletion. This condition is molecularly and clinically heterogeneous. Deletions involving two non-overlapping regions, known as the distal (telomeric) and proximal (centromeric) critical regions, are sufficient to cause the majority of the recurrent clinical features, although with different facial features and dysmorphisms. SPEN encodes a transcriptional repressor commonly deleted in proximal del1p36 syndrome and is located centromeric to the proximal 1p36 critical region. Here, we used clinical data from 34 individuals with truncating variants in SPEN to define a neurodevelopmental disorder presenting with features that overlap considerably with those of proximal del1p36 syndrome. The clinical profile of this disease includes developmental delay/intellectual disability, autism spectrum disorder, anxiety, aggressive behavior, attention deficit disorder, hypotonia, brain and spine anomalies, congenital heart defects, high/narrow palate, facial dysmorphisms, and obesity/increased BMI, especially in females. SPEN also emerges as a relevant gene for del1p36 syndrome by co-expression analyses. Finally, we show that haploinsufficiency of SPEN is associated with a distinctive DNA methylation episignature of the X chromosome in affected females, providing further evidence of a specific contribution of the protein to the epigenetic control of this chromosome, and a paradigm of an X chromosome-specific episignature that classifies syndromic traits. We conclude that SPEN is required for multiple developmental processes and SPEN haploinsufficiency is a major contributor to a disorder associated with deletions centromeric to the previously established 1p36 critical regions.

}, keywords = {Adolescent, Autism Spectrum Disorder, Child, Child, Preschool, Chromosome Deletion, Chromosome Disorders, Chromosomes, Human, Pair 1, Chromosomes, Human, X, DNA Methylation, DNA-Binding Proteins, Epigenesis, Genetic, Female, Haploinsufficiency, Humans, Intellectual Disability, Male, Neurodevelopmental Disorders, Phenotype, RNA-Binding Proteins, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2021.01.015}, author = {Radio, Francesca Clementina and Pang, Kaifang and Ciolfi, Andrea and Levy, Michael A and Hernandez-Garcia, Andres and Pedace, Lucia and Pantaleoni, Francesca and Liu, Zhandong and de Boer, Elke and Jackson, Adam and Bruselles, Alessandro and McConkey, Haley and Stellacci, Emilia and Lo Cicero, Stefania and Motta, Marialetizia and Carrozzo, Rosalba and Dentici, Maria Lisa and McWalter, Kirsty and Desai, Megha and Monaghan, Kristin G and Telegrafi, Aida and Philippe, Christophe and Vitobello, Antonio and Au, Margaret and Grand, Katheryn and Sanchez-Lara, Pedro A and Baez, Joanne and Lindstrom, Kristin and Kulch, Peggy and Sebastian, Jessica and Madan-Khetarpal, Suneeta and Roadhouse, Chelsea and MacKenzie, Jennifer J and Monteleone, Berrin and Saunders, Carol J and Jean Cuevas, July K and Cross, Laura and Zhou, Dihong and Hartley, Taila and Sawyer, Sarah L and Monteiro, Fabiola Paoli and Secches, Tania Vertemati and Kok, Fernando and Schultz-Rogers, Laura E and Macke, Erica L and Morava, Eva and Klee, Eric W and Kemppainen, Jennifer and Iascone, Maria and Selicorni, Angelo and Tenconi, Romano and Amor, David J and Pais, Lynn and Gallacher, Lyndon and Turnpenny, Peter D and Stals, Karen and Ellard, Sian and Cabet, Sara and Lesca, Gaetan and Pascal, Joset and Steindl, Katharina and Ravid, Sarit and Weiss, Karin and Castle, Alison M R and Carter, Melissa T and Kalsner, Louisa and de Vries, Bert B A and van Bon, Bregje W and Wevers, Marijke R and Pfundt, Rolph and Stegmann, Alexander P A and Kerr, Bronwyn and Kingston, Helen M and Chandler, Kate E and Sheehan, Willow and Elias, Abdallah F and Shinde, Deepali N and Towne, Meghan C and Robin, Nathaniel H and Goodloe, Dana and Vanderver, Adeline and Sherbini, Omar and Bluske, Krista and Hagelstrom, R Tanner and Zanus, Caterina and Faletra, Flavio and Musante, Luciana and Kurtz-Nelson, Evangeline C and Earl, Rachel K and Anderlid, Britt-Marie and Morin, Gilles and van Slegtenhorst, Marjon and Diderich, Karin E M and Brooks, Alice S and Gribnau, Joost and Boers, Ruben G and Finestra, Teresa Robert and Carter, Lauren B and Rauch, Anita and Gasparini, Paolo and Boycott, Kym M and Barakat, Tahsin Stefan and GrAHm, John M and Faivre, Laurence and Banka, Siddharth and Wang, Tianyun and Eichler, Evan E and Priolo, Manuela and Dallapiccola, Bruno and Vissers, Lisenka E L M and Sadikovic, Bekim and Scott, Daryl A and Holder, Jimmy Lloyd and Tartaglia, Marco} } @article {974, title = {Variants in GNAI1 cause a syndrome associated with variable features including developmental delay, seizures, and hypotonia.}, journal = {Genet Med}, volume = {23}, year = {2021}, month = {2021 05}, pages = {881-887}, abstract = {

PURPOSE: Neurodevelopmental disorders (NDDs) encompass a spectrum of genetically heterogeneous disorders with features that commonly include developmental delay, intellectual disability, and autism spectrum disorders. We sought to delineate the molecular and phenotypic spectrum of a novel neurodevelopmental disorder caused by variants in the GNAI1 gene.

METHODS: Through large cohort trio-based exome sequencing and international data-sharing, we identified 24 unrelated individuals with NDD phenotypes and a variant in GNAI1, which encodes the inhibitory Gαi1 subunit of heterotrimeric G-proteins. We collected detailed genotype and phenotype information for each affected individual.

RESULTS: We identified 16 unique variants in GNAI1 in 24 affected individuals; 23 occurred de novo and 1 was inherited from a mosaic parent. Most affected individuals have a severe neurodevelopmental disorder. Core features include global developmental delay, intellectual disability, hypotonia, and epilepsy.

CONCLUSION: This collaboration establishes GNAI1 variants as a cause of NDDs. GNAI1-related NDD is most often characterized by severe to profound delays, hypotonia, epilepsy that ranges from self-limiting to intractable, behavior problems, and variable mild dysmorphic features.

}, keywords = {Child, Developmental Disabilities, Humans, Intellectual Disability, Muscle Hypotonia, Neurodevelopmental Disorders, Seizures, Whole Exome Sequencing}, issn = {1530-0366}, doi = {10.1038/s41436-020-01076-8}, author = {Muir, Alison M and Gardner, Jennifer F and van Jaarsveld, Richard H and de Lange, Iris M and van der Smagt, Jasper J and Wilson, Golder N and Dubbs, Holly and Goldberg, Ethan M and Zitano, Lia and Bupp, Caleb and Martinez, Jose and Srour, Myriam and Accogli, Andrea and Alhakeem, Afnan and Meltzer, Meira and Gropman, Andrea and Brewer, Carole and Caswell, Richard C and Montgomery, Tara and McKenna, Caoimhe and McKee, Shane and Powell, Corinna and Vasudevan, Pradeep C and Brady, Angela F and Joss, Shelagh and Tysoe, Carolyn and Noh, Grace and Tarnopolsky, Mark and Brady, Lauren and Zafar, Muhammad and Schrier Vergano, Samantha A and Murray, Brianna and Sawyer, Lindsey and Hainline, Bryan E and Sapp, Katherine and DeMarzo, Danielle and Huismann, Darcy J and Wentzensen, Ingrid M and Schnur, Rhonda E and Monaghan, Kristin G and Juusola, Jane and Rhodes, Lindsay and Dobyns, William B and Lecoquierre, Francois and Goldenberg, Alice and Polster, Tilman and Axer-Schaefer, Susanne and Platzer, Konrad and Kl{\"o}ckner, Chiara and Hoffman, Trevor L and MacArthur, Daniel G and O{\textquoteright}Leary, Melanie C and VanNoy, Grace E and England, Eleina and Varghese, Vinod C and Mefford, Heather C} } @article {779, title = {Bi-allelic ADARB1 Variants Associated with Microcephaly, Intellectual Disability, and Seizures.}, journal = {Am J Hum Genet}, volume = {106}, year = {2020}, month = {2020 04 02}, pages = {467-483}, abstract = {

The RNA editing enzyme ADAR2 is essential for the recoding of brain transcripts. Impaired ADAR2 editing leads to early-onset epilepsy and premature death in a mouse model. Here, we report bi-allelic variants in ADARB1, the gene encoding ADAR2, in four unrelated individuals with microcephaly, intellectual disability, and epilepsy. In one individual, a homozygous variant in one of the double-stranded RNA-binding domains (dsRBDs) was identified. In the others, variants were situated in or around the deaminase domain. To evaluate the effects of these variants on ADAR2 enzymatic activity, we performed in~vitro assays with recombinant proteins in HEK293T cells and ex~vivo assays with fibroblasts derived from one of the individuals. We demonstrate that these ADAR2 variants lead to reduced editing activity on a known ADAR2 substrate. We also demonstrate that one variant leads to changes in splicing of ADARB1 transcript isoforms. These findings reinforce the importance of RNA editing in brain development and introduce ADARB1 as a genetic etiology in individuals with intellectual disability, microcephaly, and epilepsy.

}, keywords = {Adenosine Deaminase, Alleles, Alternative Splicing, Child, Child, Preschool, Genetic Predisposition to Disease, Genetic Variation, HEK293 Cells, Humans, Intellectual Disability, Male, Microcephaly, RNA Splicing, RNA-Binding Proteins, Seizures}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2020.02.015}, author = {Tan, Tiong Yang and Sedm{\'\i}k, Ji{\v r}{\'\i} and Fitzgerald, Mark P and Halevy, Rivka Sukenik and Keegan, Liam P and Helbig, Ingo and Basel-Salmon, Lina and Cohen, Lior and Straussberg, Rachel and Chung, Wendy K and Helal, Mayada and Maroofian, Reza and Houlden, Henry and Juusola, Jane and Sadedin, Simon and Pais, Lynn and Howell, Katherine B and White, Susan M and Christodoulou, John and O{\textquoteright}Connell, Mary A} } @article {945, title = {Biallelic in-frame deletion in TRAPPC4 in a family with developmental delay and cerebellar atrophy.}, journal = {Brain}, volume = {143}, year = {2020}, month = {2020 10 01}, pages = {e83}, keywords = {Atrophy, Cerebellar Diseases, Humans, Intellectual Disability, Sequence Deletion}, issn = {1460-2156}, doi = {10.1093/brain/awaa256}, author = {Saad, Ahmed K and Marafi, Dana and Mitani, Tadahiro and Jolly, Angad and Du, Haowei and Elbendary, Hasnaa M and Jhangiani, Shalini N and Akdemir, Zeynep C and Gibbs, Richard A and Hunter, Jill V and Carvalho, Claudia M B C and Pehlivan, Davut and Posey, Jennifer E and Zaki, MAH S and Lupski, James R} } @article {886, title = {Community-based recruitment and exome sequencing indicates high diagnostic yield in adults with intellectual disability.}, journal = {Mol Genet Genomic Med}, volume = {8}, year = {2020}, month = {2020 10}, pages = {e1439}, abstract = {

BACKGROUND: Establishing a genetic diagnosis for individuals with intellectual disability (ID) benefits patients and their families as it may inform the prognosis, lead to appropriate therapy, and facilitate access to medical and supportive services. Exome sequencing has been successfully applied in a diagnostic setting, but most clinical exome referrals are pediatric patients, with many adults with ID lacking a comprehensive genetic evaluation.

METHODS: Our unique recruitment strategy involved partnering with service and education providers for individuals with ID. We performed exome sequencing and analysis, and clinical variant interpretation for each recruited family.

RESULTS: All five families enrolled in the study opted-in for the return of genetic results. In three out of five families exome sequencing analysis identified pathogenic or likely pathogenic variants in KANSL1, TUSC3, and MED13L genes. Families discussed the results and any potential medical follow-up in an appointment with a board certified clinical geneticist.

CONCLUSION: Our study suggests high yield of exome sequencing as a diagnostic tool in adult patients with ID who have not undergone comprehensive sequencing-based genetic testing. Research studies including an option of return of results through a genetic clinic could help minimize the disparity in exome diagnostic testing between pediatric and adult patients with ID.

}, keywords = {Adult, Female, Genetic Testing, Humans, Independent Living, Intellectual Disability, Male, Mediator Complex, Membrane Proteins, Nuclear Proteins, Patient Selection, Sensitivity and Specificity, Tumor Suppressor Proteins, Whole Exome Sequencing}, issn = {2324-9269}, doi = {10.1002/mgg3.1439}, author = {Sabo, Aniko and Murdock, David and Dugan, Shannon and Meng, Qingchang and Gingras, Marie-Claude and Hu, Jianhong and Muzny, Donna and Gibbs, Richard} } @article {756, title = {Congenital myasthenic syndrome with mild intellectual disability caused by a recurrent SLC25A1 variant.}, journal = {Eur J Hum Genet}, volume = {28}, year = {2020}, month = {2020 03}, pages = {373-377}, abstract = {

Congenital myasthenic syndromes (CMS) are a clinically and genetically heterogeneous group of disorders caused by mutations which lead to impaired neuromuscular transmission. SLC25A1 encodes a mitochondrial citrate carrier, associated mainly with the severe neurometabolic disease combined D-2- and L-2-hydroxyglutaric aciduria (D/L-2-HGA). We previously reported a single family with a homozygous missense variant in SLC25A1 with a phenotype restricted to relatively mild CMS with intellectual disability, but to date no additional cases of this CMS subtype had been reported. Here, we performed whole exome sequencing (WES) in three additional and unrelated families presenting with CMS and mild intellectual disability to identify the underlying causative gene. The WES analysis revealed the presence of a homozygous c.740G>A; p.(Arg247Gln) missense SLC25A1 variant, the same SLC25A1 variant as identified in the original family with this phenotype. Electron microscopy of muscle from two cases revealed enlarged and accumulated mitochondria. Haplotype analysis performed in two unrelated families suggested that this variant is a result of recurrent mutation and not a founder effect. This suggests that p.(Arg247Gln) is associated with a relatively mild CMS phenotype with subtle mitochondrial abnormalities, while other variants in this gene cause more severe neurometabolic disease. In conclusion, the p.(Arg247Gln) SLC25A1 variant should be considered in patients presenting with a presynaptic CMS phenotype, particularly with accompanying intellectual disability.

}, keywords = {Adult, Female, Haplotypes, Homozygote, Humans, Intellectual Disability, Male, Mitochondrial Proteins, Muscle, Skeletal, Mutation, Missense, Myasthenic Syndromes, Congenital, Organic Anion Transporters}, issn = {1476-5438}, doi = {10.1038/s41431-019-0506-2}, author = {Balaraju, Sunitha and Topf, Ana and McMacken, Grace and Kumar, Veeramani Preethish and Pechmann, Astrid and Roper, Helen and Vengalil, Seena and Polavarapu, Kiran and Nashi, Saraswati and MAHjan, Niranjan Prakash and Barbosa, Ines A and Deshpande, Charu and Taylor, Robert W and Cossins, Judith and Beeson, David and Laurie, Steven and Kirschner, Janbernd and Horvath, Rita and McFarland, Robert and Nalini, Atchayaram and Lochm{\"u}ller, Hanns} } @article {738, title = {Deficiencies in vesicular transport mediated by TRAPPC4 are associated with severe syndromic intellectual disability.}, journal = {Brain}, volume = {143}, year = {2020}, month = {2020 01 01}, pages = {112-130}, abstract = {

The conserved transport protein particle (TRAPP) complexes regulate key trafficking events and are required for autophagy. TRAPPC4, like its yeast Trs23 orthologue, is a core component of the TRAPP complexes and one of the essential subunits for guanine nucleotide exchange factor activity for Rab1 GTPase. Pathogenic variants in specific TRAPP subunits are associated with neurological disorders. We undertook exome sequencing in three unrelated families of Caucasian, Turkish and French-Canadian ethnicities with seven affected children that showed features of early-onset seizures, developmental delay, microcephaly, sensorineural deafness, spastic quadriparesis and progressive cortical and cerebellar atrophy in an effort to determine the genetic aetiology underlying neurodevelopmental disorders. All seven affected subjects shared the same identical rare, homozygous, potentially pathogenic variant in a non-canonical, well-conserved splice site within TRAPPC4 (hg19:chr11:g.118890966A>G; TRAPPC4: NM_016146.5; c.454+3A>G). Single nucleotide polymorphism array analysis revealed there was no haplotype shared between the tested Turkish and Caucasian families suggestive of a variant hotspot region rather than a founder effect. In silico analysis predicted the variant to cause aberrant splicing. Consistent with this, experimental evidence showed both a reduction in full-length transcript levels and an increase in levels of a shorter transcript missing exon 3, suggestive of an incompletely penetrant splice defect. TRAPPC4 protein levels were significantly reduced whilst levels of other TRAPP complex subunits remained unaffected. Native polyacrylamide gel electrophoresis and size exclusion chromatography demonstrated a defect in TRAPP complex assembly and/or stability. Intracellular trafficking through the Golgi using the marker protein VSVG-GFP-ts045 demonstrated significantly delayed entry into and exit from the Golgi in fibroblasts derived from one of the affected subjects. Lentiviral expression of wild-type TRAPPC4 in these fibroblasts restored trafficking, suggesting that the trafficking defect was due to reduced TRAPPC4 levels. Consistent with the recent association of the TRAPP complex with autophagy, we found that the fibroblasts had a basal autophagy defect and a delay in autophagic flux, possibly due to unsealed autophagosomes. These results were validated using a yeast trs23 temperature sensitive variant that exhibits constitutive and stress-induced autophagic defects at permissive temperature and a secretory defect at restrictive temperature. In summary we provide strong evidence for pathogenicity of this variant in a member of the core TRAPP subunit, TRAPPC4 that associates with vesicular trafficking and autophagy defects. This is the first report of a TRAPPC4 variant, and our findings add to the growing number of TRAPP-associated neurological disorders.

}, keywords = {Atrophy, Autophagy, Cerebellum, Cerebral Cortex, Child, Child, Preschool, Craniofacial Abnormalities, Deafness, Developmental Disabilities, Epilepsy, Female, Fibroblasts, Hearing Loss, Sensorineural, Humans, Infant, Infant, Newborn, Intellectual Disability, Male, Microcephaly, Microscopy, Fluorescence, Muscle Spasticity, Nerve Tissue Proteins, Neurodevelopmental Disorders, Pedigree, Quadriplegia, RNA Splice Sites, Syndrome, Vesicular Transport Proteins}, issn = {1460-2156}, doi = {10.1093/brain/awz374}, author = {Van Bergen, Nicole J and Guo, Yiran and Al-Deri, Noraldin and Lipatova, Zhanna and Stanga, Daniela and Zhao, Sarah and Murtazina, Rakhilya and Gyurkovska, Valeriya and Pehlivan, Davut and Mitani, Tadahiro and Gezdirici, Alper and Antony, Jayne and Collins, Felicity and Willis, Mary J H and Coban Akdemir, Zeynep H and Liu, Pengfei and Punetha, Jaya and Hunter, Jill V and Jhangiani, Shalini N and Fatih, Jawid M and Rosenfeld, Jill A and Posey, Jennifer E and Gibbs, Richard A and Karaca, Ender and Massey, Sean and Ranasinghe, Thisara G and Sleiman, Patrick and Troedson, Chris and Lupski, James R and Sacher, Michael and Segev, Nava and Hakonarson, Hakon and Christodoulou, John} } @article {786, title = {Further delineation of the clinical spectrum of KAT6B disorders and allelic series of pathogenic variants.}, journal = {Genet Med}, volume = {22}, year = {2020}, month = {2020 08}, pages = {1338-1347}, abstract = {

PURPOSE: Genitopatellar syndrome and Say-Barber-Biesecker-Young-Simpson syndrome are caused by variants in the KAT6B gene and are part of a broad clinical spectrum called KAT6B disorders, whose variable expressivity is increasingly being recognized.

METHODS: We herein present the phenotypes of 32 previously unreported individuals with a molecularly confirmed diagnosis of a KAT6B disorder, report 24 new pathogenic KAT6B variants, and review phenotypic information available on all published individuals with this condition. We also suggest a classification of clinical subtypes within the KAT6B disorder spectrum.

RESULTS: We demonstrate that cerebral anomalies, optic nerve hypoplasia, neurobehavioral difficulties, and distal limb anomalies other than long thumbs and great toes, such as polydactyly, are more frequently observed than initially reported. Intestinal malrotation and its serious consequences can be present in affected individuals. Additionally, we identified four children with Pierre Robin sequence, four individuals who had increased nuchal translucency/cystic hygroma prenatally, and two fetuses with severe renal anomalies leading to renal failure. We also report an individual in which a pathogenic variant was inherited from a mildly affected parent.

CONCLUSION: Our work provides a comprehensive review and expansion of the genotypic and phenotypic spectrum of KAT6B disorders that will assist clinicians in the assessment, counseling, and management of affected individuals.

}, keywords = {Blepharophimosis, Exons, Histone Acetyltransferases, Humans, Intellectual Disability, Mutation}, issn = {1530-0366}, doi = {10.1038/s41436-020-0811-8}, author = {Zhang, Li Xin and Lemire, Gabrielle and Gonzaga-Jauregui, Claudia and Molidperee, Sirinart and Galaz-Montoya, Carolina and Liu, David S and Verloes, Alain and Shillington, Amelle G and Izumi, Kosuke and Ritter, Alyssa L and Keena, Beth and Zackai, Elaine and Li, Dong and Bhoj, Elizabeth and Tarpinian, Jennifer M and Bedoukian, Emma and Kukolich, Mary K and Innes, A Micheil and Ediae, Grace U and Sawyer, Sarah L and Nair, Karippoth Mohandas and Soumya, Para Chottil and Subbaraman, Kinattinkara R and Probst, Frank J and Bassetti, Jennifer A and Sutton, Reid V and Gibbs, Richard A and Brown, Chester and Boone, Philip M and Holm, Ingrid A and Tartaglia, Marco and Ferrero, Giovanni Battista and Niceta, Marcello and Dentici, Maria Lisa and Radio, Francesca Clementina and Keren, Boris and Wells, Constance F and Coubes, Christine and Laquerri{\`e}re, Annie and Aziza, Jacqueline and Dubucs, Charlotte and Nampoothiri, Sheela and Mowat, David and Patel, Millan S and Bracho, Ana and Cammarata-Scalisi, Francisco and Gezdirici, Alper and Fern{\'a}ndez-Ja{\'e}n, Alberto and Hauser, Natalie and Zarate, Yuri A and Bosanko, Katherine A and Dieterich, Klaus and Carey, John C and Chong, Jessica X and Nickerson, Deborah A and Bamshad, Michael J and Lee, Brendan H and Yang, Xiang-Jiao and Lupski, James R and Campeau, Philippe M} } @article {749, title = {A missense mutation in the catalytic domain of O-GlcNAc transferase links perturbations in protein O-GlcNAcylation to X-linked intellectual disability.}, journal = {FEBS Lett}, volume = {594}, year = {2020}, month = {2020 02}, pages = {717-727}, abstract = {

X-linked intellectual disabilities (XLID) are common developmental disorders. The enzyme O-GlcNAc transferase encoded by OGT, a recently discovered XLID gene, attaches O-GlcNAc to nuclear and cytoplasmic proteins. As few missense mutations have been described, it is unclear what the aetiology of the patient phenotypes is. Here, we report the discovery of a missense mutation in the catalytic domain of OGT in an XLID patient. X-ray crystallography reveals that this variant leads to structural rearrangements in the catalytic domain. The mutation reduces in~vitro OGT activity on substrate peptides/protein. Mouse embryonic stem cells carrying the mutation reveal reduced O-GlcNAcase (OGA) and global O-GlcNAc levels. These data suggest a direct link between changes in the O-GlcNAcome and intellectual disability observed in patients carrying OGT mutations.

}, keywords = {Animals, Catalytic Domain, Cell Line, Glycosylation, Humans, Intellectual Disability, Mice, Models, Molecular, Mutation, Missense, N-Acetylglucosaminyltransferases}, issn = {1873-3468}, doi = {10.1002/1873-3468.13640}, author = {Pravata, Veronica M and Gundogdu, Mehmet and Bartual, Sergio G and Ferenbach, Andrew T and Stavridis, Marios and {\~O}unap, Katrin and Pajusalu, Sander and {\v Z}ordania, Riina and Wojcik, Monica H and van Aalten, Daan M F} } @article {770, title = {MN1 C-terminal truncation syndrome is a novel neurodevelopmental and craniofacial disorder with partial rhombencephalosynapsis.}, journal = {Brain}, volume = {143}, year = {2020}, month = {2020 01 01}, pages = {55-68}, abstract = {

MN1 encodes a transcriptional co-regulator without homology to other proteins, previously implicated in acute myeloid leukaemia and development of the palate. Large deletions encompassing MN1 have been reported in individuals with variable neurodevelopmental anomalies and non-specific facial features. We identified a cluster of de novo truncating mutations in MN1 in a cohort of 23 individuals with strikingly similar dysmorphic facial features, especially midface hypoplasia, and intellectual disability with severe expressive language delay. Imaging revealed an atypical form of rhombencephalosynapsis, a distinctive brain malformation characterized by partial or complete loss of the cerebellar vermis with fusion of the cerebellar hemispheres, in 8/10 individuals. Rhombencephalosynapsis has no previously known definitive genetic or environmental causes. Other frequent features included perisylvian polymicrogyria, abnormal posterior clinoid processes and persistent trigeminal artery. MN1 is encoded by only two exons. All mutations, including the recurrent variant p.Arg1295* observed in 8/21 probands, fall in the terminal exon or the extreme 3{\textquoteright} region of exon 1, and are therefore predicted to result in escape from nonsense-mediated mRNA decay. This was confirmed in fibroblasts from three individuals. We propose that the condition described here, MN1 C-terminal truncation (MCTT) syndrome, is not due to MN1 haploinsufficiency but rather is the result of dominantly acting C-terminally truncated MN1 protein. Our data show that MN1 plays a critical role in human craniofacial and brain development, and opens the door to understanding the biological mechanisms underlying rhombencephalosynapsis.

}, keywords = {Abnormalities, Multiple, Adolescent, Basilar Artery, Carotid Arteries, Cerebellar Vermis, Cerebellum, Child, Child, Preschool, Cohort Studies, Comparative Genomic Hybridization, Craniofacial Abnormalities, Female, Fibroblasts, Humans, Imaging, Three-Dimensional, Infant, Intellectual Disability, Language Development Disorders, Magnetic Resonance Imaging, Male, Middle Aged, Mutation, Nervous System Malformations, Nonsense Mediated mRNA Decay, Polymicrogyria, Real-Time Polymerase Chain Reaction, RNA-Seq, Syndrome, Tomography, X-Ray Computed, Trans-Activators, Tumor Suppressor Proteins, Whole Exome Sequencing, Whole Genome Sequencing}, issn = {1460-2156}, doi = {10.1093/brain/awz379}, author = {Mak, Christopher C Y and Doherty, Dan and Lin, Angela E and Vegas, Nancy and Cho, Megan T and Viot, G{\'e}raldine and Dimartino, Cl{\'e}mantine and Weisfeld-Adams, James D and Lessel, Davor and Joss, Shelagh and Li, Chumei and Gonzaga-Jauregui, Claudia and Zarate, Yuri A and Ehmke, Nadja and Horn, Denise and Troyer, Caitlin and Kant, Sarina G and Lee, Youngha and Ishak, Gisele E and Leung, Gordon and Barone Pritchard, Amanda and Yang, Sandra and Bend, Eric G and Filippini, Francesca and Roadhouse, Chelsea and Lebrun, Nicolas and Mehaffey, Michele G and Martin, Pierre-Marie and Apple, Benjamin and Millan, Francisca and Puk, Oliver and Hoffer, Mariette J V and Henderson, Lindsay B and McGowan, Ruth and Wentzensen, Ingrid M and Pei, Steven and Zahir, Farah R and Yu, Mullin and Gibson, William T and Seman, Ann and Steeves, Marcie and Murrell, Jill R and Luettgen, Sabine and Francisco, Elizabeth and Strom, Tim M and Amlie-Wolf, Louise and Kaindl, Angela M and Wilson, William G and Halbach, Sara and Basel-Salmon, Lina and Lev-El, Noa and Denecke, Jonas and Vissers, Lisenka E L M and Radtke, Kelly and Chelly, Jamel and Zackai, Elaine and Friedman, Jan M and Bamshad, Michael J and Nickerson, Deborah A and Reid, Russell R and Devriendt, Koenraad and Chae, Jong-Hee and Stolerman, Elliot and McDougall, Carey and Powis, Z{\"o}e and Bienvenu, Thierry and Tan, Tiong Y and Orenstein, Naama and Dobyns, William B and Shieh, Joseph T and Choi, Murim and Waggoner, Darrel and Gripp, Karen W and Parker, Michael J and Stoler, Joan and Lyonnet, Stanislas and Cormier-Daire, Val{\'e}rie and Viskochil, David and Hoffman, Trevor L and Amiel, Jeanne and Chung, Brian H Y and Gordon, Christopher T} } @article {707, title = {Phenotypic expansion of POGZ-related intellectual disability syndrome (White-Sutton syndrome).}, journal = {Am J Med Genet A}, volume = {182}, year = {2020}, month = {2020 01}, pages = {38-52}, abstract = {

White-Sutton syndrome (WHSUS) is a recently-identified genetic disorder resulting from de novo heterozygous pathogenic variants in POGZ. Thus far, over 50 individuals have been reported worldwide, however phenotypic characterization and data regarding the natural history are still incomplete. Here we report the clinical features of 22 individuals with 21 unique loss of function POGZ variants. We observed a broad spectrum of intellectual disability and/or developmental delay with or without autism, and speech delay in all individuals. Other common problems included ocular abnormalities, hearing loss and gait abnormalities. A validated sleep disordered breathing questionnaire identified symptoms of obstructive sleep apnea in 4/12 (33\%) individuals. A higher-than-expected proportion of cases also had gastrointestinal phenotypes, both functional and anatomical, as well as genitourinary anomalies. In line with previous publications, we observed an increased body mass index (BMI) z-score compared to the general population (mean 0.59, median 0.9; p 0.0253). Common facial features included microcephaly, broad forehead, midface hypoplasia, triangular mouth, broad nasal root and flat nasal bridge. Analysis of the Baylor Genetics clinical laboratory database revealed that POGZ variants were implicated in approximately 0.14\% of cases who underwent clinical exome sequencing for neurological indications with or without involvement of other body systems. This study describes a greater allelic series and expands the phenotypic spectrum of this new syndromic form of intellectual disability and autism.

}, keywords = {Adolescent, Adult, Autistic Disorder, Child, Child, Preschool, Exome, Female, Heterozygote, Humans, Infant, Intellectual Disability, Language Development Disorders, Male, Microcephaly, Middle Aged, Mutation, Phenotype, Transposases, Whole Exome Sequencing, Young Adult}, issn = {1552-4833}, doi = {10.1002/ajmg.a.61380}, author = {Assia Batzir, Nurit and Posey, Jennifer E and Song, Xiaofei and Akdemir, Zeynep Coban and Rosenfeld, Jill A and Brown, Chester W and Chen, Emily and Holtrop, Shannon G and Mizerik, Elizabeth and Nieto Moreno, Margarita and Payne, Katelyn and Raas-Rothschild, Annick and Scott, Richard and Vernon, Hilary J and Zadeh, Neda and Lupski, James R and Sutton, V Reid} } @article {912, title = {Phenotypic spectrum and transcriptomic profile associated with germline variants in TRAF7.}, journal = {Genet Med}, volume = {22}, year = {2020}, month = {2020 07}, pages = {1215-1226}, abstract = {

PURPOSE: Somatic variants in tumor necrosis factor receptor-associated factor 7 (TRAF7) cause meningioma, while germline variants have recently been identified in seven patients with developmental delay and cardiac, facial, and digital anomalies. We aimed to define the clinical and mutational spectrum associated with TRAF7 germline variants in a large series of patients, and to determine the molecular effects of the variants through transcriptomic analysis of patient fibroblasts.

METHODS: We performed exome, targeted capture, and Sanger sequencing of patients with undiagnosed developmental disorders, in multiple independent diagnostic or research centers. Phenotypic and mutational comparisons were facilitated through data exchange platforms. Whole-transcriptome sequencing was performed on RNA from patient- and control-derived fibroblasts.

RESULTS: We identified heterozygous missense variants in TRAF7 as the cause of a developmental delay-malformation syndrome in 45 patients. Major features include a recognizable facial gestalt (characterized in particular by blepharophimosis), short neck, pectus carinatum, digital deviations, and patent ductus arteriosus. Almost all variants occur in the WD40 repeats and most are recurrent. Several differentially expressed genes were identified in patient fibroblasts.

CONCLUSION: We provide the first large-scale analysis of the clinical and mutational spectrum associated with the TRAF7 developmental syndrome, and we shed light on its molecular etiology through transcriptome studies.

}, keywords = {Exome, Germ Cells, Humans, Intellectual Disability, Mutation, Missense, Phenotype, Transcriptome, Tumor Necrosis Factor Receptor-Associated Peptides and Proteins}, issn = {1530-0366}, doi = {10.1038/s41436-020-0792-7}, author = {Castilla-Vallmanya, Laura and Selmer, Kaja K and Dimartino, Cl{\'e}mantine and Rabionet, Raquel and Blanco-S{\'a}nchez, Bernardo and Yang, Sandra and Reijnders, Margot R F and van Essen, Antonie J and Oufadem, Myriam and Vigeland, Magnus D and Stadheim, Barbro and Houge, Gunnar and Cox, Helen and Kingston, Helen and Clayton-Smith, Jill and Innis, Jeffrey W and Iascone, Maria and Cereda, Anna and Gabbiadini, Sara and Chung, Wendy K and Sanders, Victoria and Charrow, Joel and Bryant, Emily and Millichap, John and Vitobello, Antonio and Thauvin, Christel and Mau-Them, Frederic Tran and Faivre, Laurence and Lesca, Gaetan and Labalme, Audrey and Rougeot, Christelle and Chatron, Nicolas and Sanlaville, Damien and Christensen, Katherine M and Kirby, Amelia and Lewandowski, Raymond and Gannaway, Rachel and Aly, MAH and Lehman, Anna and Clarke, Lorne and Graul-Neumann, Luitgard and Zweier, Christiane and Lessel, Davor and Lozic, Bernarda and Aukrust, Ingvild and Peretz, Ryan and Stratton, Robert and Smol, Thomas and Dieux-Co{\"e}slier, Anne and Meira, Joanna and Wohler, Elizabeth and Sobreira, Nara and Beaver, Erin M and Heeley, Jennifer and Briere, Lauren C and High, Frances A and Sweetser, David A and Walker, Melissa A and Keegan, Catherine E and Jayakar, Parul and Shinawi, Marwan and Kerstjens-Frederikse, Wilhelmina S and Earl, Dawn L and Siu, Victoria M and Reesor, Emma and Yao, Tony and Hegele, Robert A and Vaske, Olena M and Rego, Shannon and Shapiro, Kevin A and Wong, Brian and Gambello, Michael J and McDonald, Marie and Karlowicz, Danielle and Colombo, Roberto and Serretti, Alessandro and Pais, Lynn and O{\textquoteright}Donnell-Luria, Anne and Wray, Alison and Sadedin, Simon and Chong, Belinda and Tan, Tiong Y and Christodoulou, John and White, Susan M and Slavotinek, Anne and Barbouth, Deborah and Morel Swols, Dayna and Parisot, M{\'e}lanie and Bole-Feysot, Christine and Nitschk{\'e}, Patrick and Pingault, V{\'e}ronique and Munnich, Arnold and Cho, Megan T and Cormier-Daire, Val{\'e}rie and Balcells, Susanna and Lyonnet, Stanislas and Grinberg, Daniel and Amiel, Jeanne and Urreizti, Roser and Gordon, Christopher T} } @article {684, title = {The pleiotropy associated with de novo variants in CHD4, CNOT3, and SETD5 extends to moyamoya angiopathy.}, journal = {Genet Med}, volume = {22}, year = {2020}, month = {2020 02}, pages = {427-431}, abstract = {

PURPOSE: Moyamoya angiopathy (MMA) is a cerebrovascular disease characterized by occlusion of large arteries, which leads to strokes starting in childhood. Twelve altered genes predispose to MMA but the majority of cases of European descent do not have an identified genetic trigger.

METHODS: Exome sequencing from 39 trios were analyzed.

RESULTS: We identified four de novo variants in three genes not previously associated with MMA: CHD4, CNOT3, and SETD5. Identification of additional rare variants in these genes in 158 unrelated MMA probands provided further support that rare pathogenic variants in CHD4 and CNOT3 predispose to MMA. Previous studies identified de novo variants in these genes in children with developmental disorders (DD), intellectual disability, and congenital heart disease.

CONCLUSION: These genes encode proteins involved in chromatin remodeling, and taken together with previously reported genes leading to MMA-like cerebrovascular occlusive disease (YY1AP1, SMARCAL1), implicate disrupted chromatin remodeling as a molecular pathway predisposing to early onset, large artery occlusive cerebrovascular disease. Furthermore, these data expand the spectrum of phenotypic pleiotropy due to alterations of CHD4, CNOT3, and SETD5 beyond DD to later onset disease in the cerebrovascular arteries and emphasize the need to assess clinical complications into adulthood for genes associated with DD.

}, keywords = {Adult, Cell Cycle Proteins, Cerebrovascular Disorders, Child, Child, Preschool, Developmental Disabilities, DNA Helicases, Exome, Female, Genetic Predisposition to Disease, Humans, Intellectual Disability, Male, Methyltransferases, Mi-2 Nucleosome Remodeling and Deacetylase Complex, Middle Aged, Moyamoya Disease, Mutation, Nuclear Proteins, Transcription Factors, Whole Exome Sequencing}, issn = {1530-0366}, doi = {10.1038/s41436-019-0639-2}, author = {Pinard, Amelie and Guey, St{\'e}phanie and Guo, Dongchuan and Cecchi, Alana C and Kharas, Natasha and Wallace, Stephanie and Regalado, Ellen S and Hostetler, Ellen M and Sharrief, Anjail Z and Bergametti, Fran{\c c}oise and Kossorotoff, Manoelle and Herv{\'e}, Dominique and Kraemer, Markus and Bamshad, Michael J and Nickerson, Deborah A and Smith, Edward R and Tournier-Lasserve, Elisabeth and Milewicz, Dianna M} } @article {940, title = {Polymicrogyria is Associated With Pathogenic Variants in PTEN.}, journal = {Ann Neurol}, volume = {88}, year = {2020}, month = {2020 12}, pages = {1153-1164}, abstract = {

OBJECTIVE: Congenital structural brain malformations have been described in patients with pathogenic phosphatase and tensin homologue (PTEN) variants, but the frequency of cortical malformations in patients with PTEN variants and their impact on clinical phenotype are not well understood. Our goal was to systematically characterize brain malformations in patients with PTEN variants and assess the relevance of their brain malformations to clinical presentation.

METHODS: We systematically searched a local radiology database for patients with PTEN variants who had available brain magnetic resonance imaging (MRI). The MRI scans were reviewed systematically for cortical abnormalities. We reviewed electroencephalogram (EEG) data and evaluated the electronic medical record for evidence of epilepsy and developmental delay.

RESULTS: In total, we identified 22 patients with PTEN pathogenic variants for which brain MRIs were available (age range 0.4-17 years). Twelve among these 22 patients (54\%) had polymicrogyria (PMG). Variants associated with PMG or atypical gyration encoded regions of the phosphatase or C2 domains of PTEN. Interestingly, epilepsy was present in only 2 of the 12 patients with PMG. We found a trend toward higher rates of global developmental delay (GDD), intellectual disability (ID), and motor delay in individuals with cortical abnormalities, although cohort size limited statistical significance.

INTERPRETATION: Malformations of cortical development, PMG in particular, represent an under-recognized phenotype associated with PTEN pathogenic variants and may have an association with cognitive and motor delays. Epilepsy was infrequent compared to the previously reported high risk of epilepsy in patients with PMG. ANN NEUROL 2020;88:1153-1164.

}, keywords = {Adolescent, Brain, Child, Child, Preschool, Comorbidity, Databases, Genetic, Developmental Disabilities, Electroencephalography, Female, Humans, Infant, Intellectual Disability, Magnetic Resonance Imaging, Male, Massachusetts, Neuroimaging, Polymicrogyria, PTEN Phosphohydrolase}, issn = {1531-8249}, doi = {10.1002/ana.25904}, author = {Shao, Diane D and Achkar, Christelle M and Lai, Abbe and Srivastava, Siddharth and Doan, Ryan N and Rodan, Lance H and Chen, Allen Y and Poduri, Annapurna and Yang, Edward and Walsh, Christopher A} } @article {580, title = {De novo and inherited TCF20 pathogenic variants are associated with intellectual disability, dysmorphic features, hypotonia, and neurological impairments with similarities to Smith-Magenis syndrome.}, journal = {Genome Med}, volume = {11}, year = {2019}, month = {2019 02 28}, pages = {12}, abstract = {

BACKGROUND: Neurodevelopmental disorders are genetically and phenotypically heterogeneous encompassing developmental delay (DD), intellectual disability (ID), autism spectrum disorders (ASDs), structural brain abnormalities, and neurological manifestations with variants in a large number of genes (hundreds) associated. To date, a few de novo mutations potentially disrupting TCF20 function in patients with ID, ASD, and hypotonia have been reported. TCF20 encodes a transcriptional co-regulator structurally related to RAI1, the dosage-sensitive gene responsible for Smith-Magenis syndrome (deletion/haploinsufficiency) and Potocki-Lupski syndrome (duplication/triplosensitivity).

METHODS: Genome-wide analyses by exome sequencing (ES) and chromosomal microarray analysis (CMA) identified individuals with heterozygous, likely damaging, loss-of-function alleles in TCF20. We implemented further molecular and clinical analyses to determine the inheritance of the pathogenic variant alleles and studied the spectrum of phenotypes.

RESULTS: We report 25 unique inactivating single nucleotide variants/indels (1 missense, 1 canonical splice-site variant, 18 frameshift, and 5 nonsense) and 4 deletions of TCF20. The pathogenic variants were detected in 32 patients and 4 affected parents from 31 unrelated families. Among cases with available parental samples, the variants were de novo in 20 instances and inherited from 4 symptomatic parents in 5, including in one set of monozygotic twins. Two pathogenic loss-of-function variants were recurrent in unrelated families. Patients presented with a phenotype characterized by developmental delay, intellectual disability, hypotonia, variable dysmorphic features, movement disorders, and sleep disturbances.

CONCLUSIONS: TCF20 pathogenic variants are associated with a novel syndrome manifesting clinical characteristics similar to those observed in Smith-Magenis syndrome. Together with previously described cases, the clinical entity of TCF20-associated neurodevelopmental disorders (TAND) emerges from a genotype-driven perspective.

}, keywords = {Adolescent, Child, Child, Preschool, Craniofacial Abnormalities, Developmental Disabilities, Female, Humans, INDEL Mutation, Infant, Intellectual Disability, Male, Muscle Hypotonia, Smith-Magenis Syndrome, Transcription Factors, Young Adult}, issn = {1756-994X}, doi = {10.1186/s13073-019-0623-0}, author = {Vetrini, Francesco and McKee, Shane and Rosenfeld, Jill A and Suri, Mohnish and Lewis, Andrea M and Nugent, Kimberly Margaret and Roeder, Elizabeth and Littlejohn, Rebecca O and Holder, Sue and Zhu, Wenmiao and Alaimo, Joseph T and Graham, Brett and Harris, Jill M and Gibson, James B and Pastore, Matthew and McBride, Kim L and Komara, Makanko and Al-Gazali, Lihadh and Al Shamsi, Aisha and Fanning, Elizabeth A and Wierenga, Klaas J and Scott, Daryl A and Ben-Neriah, Ziva and Meiner, Vardiella and Cassuto, Hanoch and Elpeleg, Orly and Holder, J Lloyd and Burrage, Lindsay C and Seaver, Laurie H and Van Maldergem, Lionel and Mahida, Sonal and Soul, Janet S and Marlatt, Margaret and Matyakhina, Ludmila and Vogt, Julie and Gold, June-Anne and Park, Soo-Mi and Varghese, Vinod and Lampe, Anne K and Kumar, Ajith and Lees, Melissa and Holder-Espinasse, Muriel and McConnell, Vivienne and Bernhard, Birgitta and Blair, Ed and Harrison, Victoria and Muzny, Donna M and Gibbs, Richard A and Elsea, Sarah H and Posey, Jennifer E and Bi, Weimin and Lalani, Seema and Xia, Fan and Yang, Yaping and Eng, Christine M and Lupski, James R and Liu, Pengfei} } @article {577, title = {ZMIZ1 Variants Cause a Syndromic Neurodevelopmental Disorder.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 02 07}, pages = {319-330}, abstract = {

ZMIZ1 is a coactivator of several transcription factors, including p53, the androgen receptor, and NOTCH1. Here, we report 19 subjects with intellectual disability and developmental delay carrying variants in ZMIZ1. The associated features include growth failure, feeding difficulties, microcephaly, facial dysmorphism, and various other congenital malformations. Of these 19, 14 unrelated subjects carried de~novo heterozygous single-nucleotide variants (SNVs) or single-base insertions/deletions, 3 siblings harbored a heterozygous single-base insertion, and 2 subjects had a balanced translocation disrupting ZMIZ1 or involving a regulatory region of ZMIZ1. In total, we identified 13 point mutations that affect key protein regions, including a SUMO acceptor site, a central disordered alanine-rich motif, a proline-rich domain, and a transactivation domain. All identified variants were absent from all available exome and genome databases. In~vitro, ZMIZ1 showed impaired coactivation of the androgen receptor. In~vivo, overexpression of ZMIZ1 mutant alleles in developing mouse brains using in utero electroporation resulted in abnormal pyramidal neuron morphology, polarization, and positioning, underscoring the importance of ZMIZ1 in neural development and supporting mutations in ZMIZ1 as the cause of a rare neurodevelopmental syndrome.

}, keywords = {Alleles, Animals, Child, Child, Preschool, Developmental Disabilities, Female, Humans, Infant, Intellectual Disability, Male, Mice, Point Mutation, Syndrome, Transcription Factors}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.12.007}, author = {Carapito, Raphael and Ivanova, Ekaterina L and Morlon, Aurore and Meng, Linyan and Molitor, Anne and Erdmann, Eva and Kieffer, Bruno and Pichot, Ang{\'e}lique and Naegely, Lydie and Kolmer, Aline and Paul, Nicod{\`e}me and Hanauer, Antoine and Tran Mau-Them, Fr{\'e}d{\'e}ric and Jean-Mar{\c c}ais, Nolwenn and Hiatt, Susan M and Cooper, Gregory M and Tvrdik, Tatiana and Muir, Alison M and Dimartino, Cl{\'e}mantine and Chopra, Maya and Amiel, Jeanne and Gordon, Christopher T and Dutreux, Fabien and Garde, Aurore and Thauvin-Robinet, Christel and Wang, Xia and Leduc, Magalie S and Phillips, Meredith and Crawford, Heather P and Kukolich, Mary K and Hunt, David and Harrison, Victoria and Kharbanda, Mira and Smigiel, Robert and Gold, Nina and Hung, Christina Y and Viskochil, David H and Dugan, Sarah L and Bayrak-Toydemir, Pinar and Joly-Helas, G{\'e}raldine and Guerrot, Anne-Marie and Schluth-Bolard, Caroline and Rio, Marl{\`e}ne and Wentzensen, Ingrid M and McWalter, Kirsty and Schnur, Rhonda E and Lewis, Andrea M and Lalani, Seema R and Mensah-Bonsu, No{\"e}l and C{\'e}raline, Jocelyn and Sun, Zijie and Ploski, Rafal and Bacino, Carlos A and Mefford, Heather C and Faivre, Laurence and Bodamer, Olaf and Chelly, Jamel and Isidor, Bertrand and Bahram, Seiamak} } @article {436, title = {Additional features of Gillespie syndrome in two Brazilian siblings with a novel ITPR1 homozygous pathogenic variant.}, journal = {Eur J Med Genet}, volume = {61}, year = {2018}, month = {2018 Mar}, pages = {134-138}, abstract = {

Gillespie syndrome (GS) [MIM: 206700] is a very rare condition characterized by bilateral iris defect, congenital hypotonia, cerebellar ataxia and intellectual disability. The typical iris anomaly is considered necessary to the diagnosis of GS. Recently, variants in ITPR1 were described causing GS. Non-neurological features were reported in few patients. Here we describe two consanguineous siblings with GS and a novel homozygous ITPR1 pathogenic variant (p.N984fs). They also present a cardiac defect (pulmonary valve stenosis) and one sib had a genitourinary malformation (ureteropelvic junction obstruction). Our report reinforces ITPR1 as the cause of GS and suggests a possible role of ITPR1 in the development of other organs.

}, keywords = {Aniridia, Brazil, Cerebellar Ataxia, Child, Preschool, Consanguinity, Female, Homozygote, Humans, Infant, Inositol 1,4,5-Trisphosphate Receptors, Intellectual Disability, Male, Mutation, Pedigree, Siblings}, issn = {1878-0849}, doi = {10.1016/j.ejmg.2017.11.005}, author = {Carvalho, Daniel R and Medeiros, Jo{\~a}o Eugenio G and Ribeiro, Daniela Sebestyan M and Martins, Bernardo J A F and Sobreira, Nara L M} } @article {452, title = {Biallelic variants in KIF14 cause intellectual disability with microcephaly.}, journal = {Eur J Hum Genet}, volume = {26}, year = {2018}, month = {2018 03}, pages = {330-339}, abstract = {

Kinesin proteins are critical for various cellular functions such as intracellular transport and cell division, and many members of the family have been linked to monogenic disorders and cancer. We report eight individuals with intellectual disability and microcephaly from four unrelated families with parental consanguinity. In the affected individuals of each family, homozygosity for likely pathogenic variants in KIF14 were detected; two loss-of-function (p.Asn83Ilefs*3 and p.Ser1478fs), and two missense substitutions (p.Ser841Phe and p.Gly459Arg). KIF14 is a mitotic motor protein that is required for spindle localization of the mitotic citron rho-interacting kinase, CIT, also mutated in microcephaly. Our results demonstrate the involvement of KIF14 in development and reveal a wide phenotypic variability ranging from fetal lethality to moderate developmental delay and microcephaly.

}, keywords = {Child, Child, Preschool, Female, Humans, Intellectual Disability, Kinesin, Loss of Function Mutation, Microcephaly, Mutation, Missense, Oncogene Proteins, Pedigree, Phenotype, Protein Domains, Syndrome}, issn = {1476-5438}, doi = {10.1038/s41431-017-0088-9}, author = {Makrythanasis, Periklis and Maroofian, Reza and Stray-Pedersen, Asbj{\o}rg and Musaev, Damir and Zaki, Maha S and Mahmoud, Iman G and Selim, Laila and Elbadawy, Amera and Jhangiani, Shalini N and Coban Akdemir, Zeynep H and Gambin, Tomasz and Sorte, Hanne S and Heiberg, Arvid and McEvoy-Venneri, Jennifer and James, Kiely N and Stanley, Valentina and Belandres, Denice and Guipponi, Michel and Santoni, Federico A and Ahangari, Najmeh and Tara, Fatemeh and Doosti, Mohammad and Iwaszkiewicz, Justyna and Zoete, Vincent and Backe, Paul Hoff and Hamamy, Hanan and Gleeson, Joseph G and Lupski, James R and Karimiani, Ehsan Ghayoor and Antonarakis, Stylianos E} } @article {491, title = {Dual Molecular Effects of Dominant RORA Mutations Cause Two Variants of Syndromic Intellectual Disability with Either Autism or Cerebellar Ataxia.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 05 03}, pages = {744-759}, abstract = {

RORα, the RAR-related orphan nuclear receptor alpha, is essential for cerebellar development. The spontaneous mutant mouse staggerer, with an ataxic gait caused by neurodegeneration of cerebellar Purkinje cells, was discovered two decades ago to result from homozygous intragenic Rora deletions. However, RORA mutations were hitherto undocumented in humans. Through a multi-centric collaboration, we identified three copy-number variant deletions (two de novo and one dominantly inherited in three generations), one de novo disrupting duplication, and nine de novo point mutations (three truncating, one canonical splice site, and five missense mutations) involving RORA in 16 individuals from 13 families with variable neurodevelopmental delay and intellectual disability (ID)-associated autistic features, cerebellar ataxia, and epilepsy. Consistent with the human and mouse data, disruption of the D.~rerio ortholog, roraa, causes significant reduction in the size of the developing cerebellum. Systematic in~vivo complementation studies showed that, whereas wild-type human RORA mRNA could complement the cerebellar pathology, missense variants had two distinct pathogenic mechanisms of either haploinsufficiency or a dominant toxic effect according to their localization in the ligand-binding or DNA-binding domains, respectively. This dichotomous direction of effect is likely relevant to the phenotype in humans: individuals with loss-of-function variants leading to haploinsufficiency show ID with autistic features, while individuals with de novo dominant toxic variants present with ID, ataxia, and cerebellar atrophy. Our combined genetic and functional data highlight the complex mutational landscape at the human RORA locus and suggest that dual mutational effects likely determine phenotypic outcome.

}, keywords = {Adolescent, Adult, Aged, 80 and over, Alleles, Animals, Autistic Disorder, Brain, Cerebellar Ataxia, Child, Child, Preschool, Disease Models, Animal, DNA Copy Number Variations, Female, Genes, Dominant, Genetic Complementation Test, Humans, Intellectual Disability, Larva, Magnetic Resonance Imaging, Male, Middle Aged, Mutation, Missense, Nuclear Receptor Subfamily 1, Group F, Member 1, Purkinje Cells, Syndrome, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.02.021}, author = {Guissart, Claire and Latypova, X{\'e}nia and Rollier, Paul and Khan, Tahir N and Stamberger, Hannah and McWalter, Kirsty and Cho, Megan T and Kjaergaard, Susanne and Weckhuysen, Sarah and Lesca, Gaetan and Besnard, Thomas and {\~O}unap, Katrin and Schema, Lynn and Chiocchetti, Andreas G and McDonald, Marie and de Bellescize, Julitta and Vincent, Marie and Van Esch, Hilde and Sattler, Shannon and Forghani, Irman and Thiffault, Isabelle and Freitag, Christine M and Barbouth, Deborah Sara and Cadieux-Dion, Maxime and Willaert, Rebecca and Guillen Sacoto, Maria J and Safina, Nicole P and Dubourg, Christ{\`e}le and Grote, Lauren and Carr{\'e}, Wilfrid and Saunders, Carol and Pajusalu, Sander and Farrow, Emily and Boland, Anne and Karlowicz, Danielle Hays and Deleuze, Jean-Fran{\c c}ois and Wojcik, Monica H and Pressman, Rena and Isidor, Bertrand and Vogels, Annick and Van Paesschen, Wim and Al-Gazali, Lihadh and Al Shamsi, Aisha Mohamed and Claustres, Mireille and Pujol, Aurora and Sanders, Stephan J and Rivier, Fran{\c c}ois and Leboucq, Nicolas and Cogn{\'e}, Benjamin and Sasorith, Souphatta and Sanlaville, Damien and Retterer, Kyle and Odent, Sylvie and Katsanis, Nicholas and B{\'e}zieau, St{\'e}phane and Koenig, Michel and Davis, Erica E and Pasquier, Laurent and K{\"u}ry, S{\'e}bastien} } @article {498, title = {Novel candidate genes and variants underlying autosomal recessive neurodevelopmental disorders with intellectual disability.}, journal = {Hum Genet}, volume = {137}, year = {2018}, month = {2018 Sep}, pages = {735-752}, abstract = {

Identification of Mendelian genes for neurodevelopmental disorders using exome sequencing to study autosomal recessive (AR) consanguineous pedigrees has been highly successful. To identify causal variants for syndromic and non-syndromic intellectual disability (ID), exome sequencing was performed using DNA samples from 22 consanguineous Pakistani families with ARID, of which 21 have additional phenotypes including microcephaly. To aid in variant identification, homozygosity mapping and linkage analysis were performed. DNA samples from affected family member(s) from every pedigree underwent exome sequencing. Identified rare damaging exome variants were tested for co-segregation with ID using Sanger sequencing. For seven ARID families, variants were identified in genes not previously associated with ID, including: EI24, FXR1 and TET3 for which knockout mouse models have brain defects; and CACNG7 and TRAPPC10 where cell studies suggest roles in important neural pathways. For two families, the novel ARID genes CARNMT1 and GARNL3 lie within previously reported ID microdeletion regions. We also observed homozygous variants in two ID candidate genes, GRAMD1B and TBRG1, for which each has been previously reported in a single family. An additional 14 families have homozygous variants in established ID genes, of which 11 variants are novel. All ARID genes have increased expression in specific structures of the developing and adult human brain and 91\% of the genes are differentially expressed in utero or during early childhood. The identification of novel ARID candidate genes and variants adds to the knowledge base that is required to further understand human brain function and development.

}, keywords = {Adult, Consanguinity, Family, Female, Genes, Recessive, Genetic Markers, Humans, Intellectual Disability, Male, Middle Aged, Mutation, Neurodevelopmental Disorders, Pedigree}, issn = {1432-1203}, doi = {10.1007/s00439-018-1928-6}, author = {Santos-Cortez, Regie Lyn P and Khan, Valeed and Khan, Falak Sher and Mughal, Zaib-Un-Nisa and Chakchouk, Imen and Lee, Kwanghyuk and Rasheed, Memoona and Hamza, Rifat and Acharya, Anushree and Ullah, Ehsan and Saqib, Muhammad Arif Nadeem and Abbe, Izoduwa and Ali, Ghazanfar and Hassan, Muhammad Jawad and Khan, Saadullah and Azeem, Zahid and Ullah, Irfan and Bamshad, Michael J and Nickerson, Deborah A and Schrauwen, Isabelle and Ahmad, Wasim and Ansar, Muhammad and Leal, Suzanne M} } @article {613, title = {A novel NAA10 variant with impaired acetyltransferase activity causes developmental delay, intellectual disability, and hypertrophic cardiomyopathy.}, journal = {Eur J Hum Genet}, volume = {26}, year = {2018}, month = {2018 09}, pages = {1294-1305}, abstract = {

The NAA10-NAA15 complex (NatA) is an N-terminal acetyltransferase that catalyzes N-terminal acetylation of ~40\% of all human proteins. N-terminal acetylation has several different roles in the cell, including altering protein stability and degradation, protein localization and protein-protein interactions. In recent years several X-linked NAA10 variants have been associated with genetic disorders. We have identified a previously undescribed NAA10 c.215T>C p.(Ile72Thr) variant in three boys from two unrelated families with a milder phenotypic spectrum in comparison to most of the previously described patients with NAA10 variants. These boys have development delay, intellectual disability, and cardiac abnormalities as overlapping phenotypes. Functional studies reveal that NAA10 Ile72Thr is destabilized, while binding to NAA15 most likely is intact. Surprisingly, the NatA activity of NAA10 Ile72Thr appears normal while its monomeric activity is decreased. This study further broadens the phenotypic spectrum associated with NAA10 deficiency, and adds to the evidence that genotype-phenotype correlations for NAA10 variants are much more complex than initially anticipated.

}, keywords = {Cardiomyopathy, Hypertrophic, Child, Preschool, Developmental Disabilities, Enzyme Stability, HeLa Cells, Humans, Infant, Intellectual Disability, Male, Mutation, N-Terminal Acetyltransferase A, N-Terminal Acetyltransferase E, Phenotype, Protein Binding, Syndrome}, issn = {1476-5438}, doi = {10.1038/s41431-018-0136-0}, author = {St{\o}ve, Svein Isungset and Blenski, Marina and Stray-Pedersen, Asbj{\o}rg and Wierenga, Klaas J and Jhangiani, Shalini N and Akdemir, Zeynep Coban and Crawford, David and McTiernan, Nina and Myklebust, Line M and Purcarin, Gabriela and McNall-Knapp, Rene and Wadley, Alexandrea and Belmont, John W and Kim, Jeffrey J and Lupski, James R and Arnesen, Thomas} } @article {464, title = {Truncating Variants in NAA15 Are Associated with Variable Levels of Intellectual Disability, Autism Spectrum Disorder, and Congenital Anomalies.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 05 03}, pages = {985-994}, abstract = {

N-alpha-acetylation is a common co-translational protein modification that is essential for normal cell function in humans. We previously identified the genetic basis of an X-linked infantile lethal Mendelian disorder involving a c.109T>C (p.Ser37Pro) missense variant in NAA10, which encodes the catalytic subunit of the N-terminal acetyltransferase A (NatA) complex. The auxiliary subunit of the NatA complex, NAA15, is the dimeric binding partner for NAA10. Through a genotype-first approach with whole-exome or genome sequencing (WES/WGS) and targeted sequencing analysis, we identified and phenotypically characterized 38 individuals from 33 unrelated families with 25 different de novo or inherited, dominantly acting likely gene disrupting (LGD) variants in NAA15. Clinical features of affected individuals with LGD variants in NAA15 include variable levels of intellectual disability, delayed speech and motor milestones, and autism spectrum disorder. Additionally, mild craniofacial dysmorphology, congenital cardiac anomalies, and seizures are present in some subjects. RNA analysis in cell lines from two individuals showed degradation of the transcripts with LGD variants, probably as a result of nonsense-mediated decay. Functional assays in yeast confirmed a deleterious effect for two of the LGD variants in NAA15. Further supporting a mechanism of haploinsufficiency, individuals with copy-number variant (CNV) deletions involving NAA15 and surrounding genes can present with mild intellectual disability, mild dysmorphic features, motor delays, and decreased growth. We propose that defects in NatA-mediated N-terminal acetylation (NTA) lead to variable levels of neurodevelopmental disorders in humans, supporting the importance of the NatA complex in normal human development.

}, keywords = {Abnormalities, Multiple, Adolescent, Adult, Autism Spectrum Disorder, Cell Line, Child, Exons, Female, Gene Expression Regulation, Genetic Predisposition to Disease, Genetic Variation, Humans, Intellectual Disability, Male, Middle Aged, Mutation, N-Terminal Acetyltransferase A, N-Terminal Acetyltransferase E, Pedigree, Phenotype, RNA, Messenger, Saccharomyces cerevisiae}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.03.004}, author = {Cheng, Hanyin and Dharmadhikari, Avinash V and Varland, Sylvia and Ma, Ning and Domingo, Deepti and Kleyner, Robert and Rope, Alan F and Yoon, Margaret and Stray-Pedersen, Asbj{\o}rg and Posey, Jennifer E and Crews, Sarah R and Eldomery, Mohammad K and Akdemir, Zeynep Coban and Lewis, Andrea M and Sutton, Vernon R and Rosenfeld, Jill A and Conboy, Erin and Agre, Katherine and Xia, Fan and Walkiewicz, Magdalena and Longoni, Mauro and High, Frances A and van Slegtenhorst, Marjon A and Mancini, Grazia M S and Finnila, Candice R and van Haeringen, Arie and den Hollander, Nicolette and Ruivenkamp, Claudia and Naidu, Sakkubai and Mahida, Sonal and Palmer, Elizabeth E and Murray, Lucinda and Lim, Derek and Jayakar, Parul and Parker, Michael J and Giusto, Stefania and Stracuzzi, Emanuela and Romano, Corrado and Beighley, Jennifer S and Bernier, Raphael A and K{\"u}ry, S{\'e}bastien and Nizon, Mathilde and Corbett, Mark A and Shaw, Marie and Gardner, Alison and Barnett, Christopher and Armstrong, Ruth and Kassahn, Karin S and Van Dijck, Anke and Vandeweyer, Geert and Kleefstra, Tjitske and Schieving, Jolanda and Jongmans, Marjolijn J and de Vries, Bert B A and Pfundt, Rolph and Kerr, Bronwyn and Rojas, Samantha K and Boycott, Kym M and Person, Richard and Willaert, Rebecca and Eichler, Evan E and Kooy, R Frank and Yang, Yaping and Wu, Joseph C and Lupski, James R and Arnesen, Thomas and Cooper, Gregory M and Chung, Wendy K and Gecz, Jozef and Stessman, Holly A F and Meng, Linyan and Lyon, Gholson J} } @article {335, title = {De Novo Disruption of the Proteasome Regulatory Subunit PSMD12 Causes a Syndromic Neurodevelopmental Disorder.}, journal = {Am J Hum Genet}, volume = {100}, year = {2017}, month = {2017 Feb 02}, pages = {352-363}, abstract = {

Degradation of proteins by the ubiquitin-proteasome system (UPS) is an essential biological process in the development of eukaryotic organisms. Dysregulation of this mechanism leads to numerous human neurodegenerative or neurodevelopmental disorders. Through a multi-center collaboration, we identified six de novo genomic deletions and four de novo point mutations involving PSMD12, encoding the non-ATPase subunit PSMD12 (aka RPN5) of the 19S regulator of 26S proteasome complex, in unrelated individuals with intellectual disability, congenital malformations, ophthalmologic anomalies, feeding difficulties, deafness, and subtle dysmorphic facial features. We observed reduced PSMD12 levels and an accumulation of ubiquitinated proteins without any impairment of proteasome catalytic activity. Our PSMD12 loss-of-function zebrafish CRISPR/Cas9 model exhibited microcephaly, decreased convolution of the renal tubules, and abnormal craniofacial morphology. Our data support the biological importance of PSMD12 as a scaffolding subunit in proteasome function during development and neurogenesis in particular; they enable the definition of a neurodevelopmental disorder due to PSMD12 variants, expanding the phenotypic spectrum of UPS-dependent disorders.

}, keywords = {Adolescent, Animals, Child, Child, Preschool, Disease Models, Animal, DNA Copy Number Variations, Down-Regulation, Female, Gene Deletion, Humans, Infant, Intellectual Disability, Male, Microcephaly, Neurodevelopmental Disorders, Polymorphism, Single Nucleotide, Proteasome Endopeptidase Complex, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.01.003}, author = {K{\"u}ry, S{\'e}bastien and Besnard, Thomas and Ebstein, Fr{\'e}d{\'e}ric and Khan, Tahir N and Gambin, Tomasz and Douglas, Jessica and Bacino, Carlos A and Craigen, William J and Sanders, Stephan J and Lehmann, Andrea and Latypova, X{\'e}nia and Khan, Kamal and Pacault, Mathilde and Sacharow, Stephanie and Glaser, Kimberly and Bieth, Eric and Perrin-Sabourin, Laurence and Jacquemont, Marie-Line and Cho, Megan T and Roeder, Elizabeth and Denomm{\'e}-Pichon, Anne-Sophie and Monaghan, Kristin G and Yuan, Bo and Xia, Fan and Simon, Sylvain and Bonneau, Dominique and Parent, Philippe and Gilbert-Dussardier, Brigitte and Odent, Sylvie and Toutain, Annick and Pasquier, Laurent and Barbouth, Deborah and Shaw, Chad A and Patel, Ankita and Smith, Janice L and Bi, Weimin and Schmitt, S{\'e}bastien and Deb, Wallid and Nizon, Mathilde and Mercier, Sandra and Vincent, Marie and Rooryck, Caroline and Malan, Val{\'e}rie and Brice{\~n}o, Ignacio and G{\'o}mez, Alberto and Nugent, Kimberly M and Gibson, James B and Cogn{\'e}, Benjamin and Lupski, James R and Stessman, Holly A F and Eichler, Evan E and Retterer, Kyle and Yang, Yaping and Redon, Richard and Katsanis, Nicholas and Rosenfeld, Jill A and Kloetzel, Peter-Michael and Golzio, Christelle and B{\'e}zieau, St{\'e}phane and Stankiewicz, Pawe{\l} and Isidor, Bertrand} } @article {424, title = {De Novo Missense Mutations in DHX30 Impair Global Translation and Cause a Neurodevelopmental Disorder.}, journal = {Am J Hum Genet}, volume = {101}, year = {2017}, month = {2017 Nov 02}, pages = {716-724}, abstract = {

DHX30 is a member of the family of DExH-box helicases, which use ATP hydrolysis to unwind RNA secondary structures. Here we identified six different de novo missense mutations in DHX30 in twelve unrelated individuals affected by global developmental delay (GDD), intellectual disability (ID), severe speech impairment and gait abnormalities. While four mutations are recurrent, two are unique with one affecting the codon of one recurrent mutation. All amino acid changes are located within highly conserved helicase motifs and were found to either impair ATPase activity or RNA recognition in different in~vitro assays. Moreover, protein variants exhibit an increased propensity to trigger stress granule (SG) formation resulting in global translation inhibition. Thus, our findings highlight the prominent role of translation control in development and function of the central nervous system and also provide molecular insight into how DHX30 dysfunction might cause a neurodevelopmental disorder.

}, keywords = {Adenosine Triphosphatases, Adolescent, Amino Acids, Cell Line, Cell Line, Tumor, Central Nervous System, Child, Child, Preschool, Developmental Disabilities, Female, HEK293 Cells, Humans, Intellectual Disability, Male, Mutation, Missense, RNA, RNA Helicases}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.09.014}, author = {Lessel, Davor and Schob, Claudia and K{\"u}ry, S{\'e}bastien and Reijnders, Margot R F and Harel, Tamar and Eldomery, Mohammad K and Coban-Akdemir, Zeynep and Denecke, Jonas and Edvardson, Shimon and Colin, Estelle and Stegmann, Alexander P A and Gerkes, Erica H and Tessarech, Marine and Bonneau, Dominique and Barth, Magalie and Besnard, Thomas and Cogn{\'e}, Benjamin and Revah-Politi, Anya and Strom, Tim M and Rosenfeld, Jill A and Yang, Yaping and Posey, Jennifer E and Immken, LaDonna and Oundjian, Nelly and Helbig, Katherine L and Meeks, Naomi and Zegar, Kelsey and Morton, Jenny and Schieving, Jolanda H and Claasen, Ana and Huentelman, Matthew and Narayanan, Vinodh and Ramsey, Keri and Brunner, Han G and Elpeleg, Orly and Mercier, Sandra and B{\'e}zieau, St{\'e}phane and Kubisch, Christian and Kleefstra, Tjitske and Kindler, Stefan and Lupski, James R and Kreienkamp, Hans-J{\"u}rgen} } @article {633, title = {De novo mutations in HNRNPU result in a neurodevelopmental syndrome.}, journal = {Am J Med Genet A}, volume = {173}, year = {2017}, month = {2017 Nov}, pages = {3003-3012}, abstract = {

Exome sequencing in the context of developmental disorders is a useful technique, but variants found need to be interpreted in the context of detailed phenotypic information. Whole gene deletions and loss-of-function-mutations in the HNRNPU gene have been associated with intellectual disability and seizures in some patients. However, a unifying syndromic phenotype has not been previously elucidated. Here, we report a total of seven patients (six patients identified through the Wellcome Trust Deciphering Developmental Disorders study, with one additional patient), who have heterozygous de novo mutations in HNRNPU. These were found via trio-based exome sequencing. All but one of the mutations is predicted to cause loss-of-function. These patients have dysmorphic features in common, including prominent eyebrows, long palpebral fissures, overhanging columella, and thin upper lip. All patients have developmental delay and intellectual disability (ID), ranging from moderate to severe. Seizures are common from early childhood. These initially occur in the context of febrile episodes. This series demonstrates common phenotypic features, including emerging dysmorphism, associated with heterozygous HNRNPU mutations. This allows us to define a novel neurodevelopmental syndrome, with a likely mechanism of haploinsufficiency.

}, keywords = {Adolescent, Adult, Child, Child, Preschool, Developmental Disabilities, Exome, Female, Genetic Predisposition to Disease, Haploinsufficiency, Heterogeneous-Nuclear Ribonucleoprotein U, Heterozygote, Humans, Infant, Intellectual Disability, Male, Mutation, Neurodevelopmental Disorders, Phenotype, Seizures, Young Adult}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38492}, author = {Yates, T Michael and Vasudevan, Pradeep C and Chandler, Kate E and Donnelly, Deirdre E and Stark, Zornitza and Sadedin, Simon and Willoughby, Josh and Balasubramanian, Meena} } @article {361, title = {Dual molecular diagnosis contributes to atypical Prader-Willi phenotype in monozygotic twins.}, journal = {Am J Med Genet A}, volume = {173}, year = {2017}, month = {2017 Sep}, pages = {2451-2455}, abstract = {

We describe monozygotic twin girls with genetic variation at two separate loci resulting in a blended phenotype of Prader-Willi syndrome and Pitt-Hopkins syndrome. These girls were diagnosed in early infancy with Prader-Willi syndrome, but developed an atypical phenotype, with apparent intellectual deficiency and lack of obesity. Array-comparative genomic hybridization confirmed a de novo paternal deletion of the 15q11.2q13 region and exome sequencing identified a second mutational event in both girls, which was a novel variant c.145+1G>A affecting a TCF4 canonical splicing site inherited from the mosaic mother. RNA studies showed that the variant abolished the donor splicing site, which was accompanied by activation of an alternative non-canonical splicing-site which then predicts a premature stop codon in the following exon. Clinical re-evaluation of the twins indicated that both variants are likely contributing to the more severe phenotypic presentation. Our data show that atypical clinical presentations may actually be the expression of blended clinical phenotypes arising from independent pathogenic events at two loci.

}, keywords = {Adolescent, Base Sequence, Child, Chromosome Deletion, Chromosomes, Human, Pair 15, Comparative Genomic Hybridization, Exome, Facies, Female, Humans, Hyperventilation, Intellectual Disability, Obesity, Pathology, Molecular, Phenotype, Prader-Willi Syndrome, Transcription Factor 4, Twins, Monozygotic}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38315}, author = {Jehee, Fernanda S and de Oliveira, Valdirene T and Gurgel-Giannetti, Juliana and Pietra, Rafaella X and Rubatino, Fernando V M and Carobin, Nat{\'a}lia V and Vianna, Gabrielle S and de Freitas, Mariana L and Fernandes, Karla S and Ribeiro, Beatriz S V and Br{\"u}ggenwirth, Hennie T and Ali-Amin, Roza and White, Janson J and Akdemir, Zeynep C and Jhangiani, Shalini N and Gibbs, Richard A and Lupski, James R and Varela, Monica C and Koiffmann, C{\'e}lia and Rosenberg, Carla and Carvalho, Claudia M B} } @article {369, title = {Haploinsufficiency of the E3 ubiquitin-protein ligase gene TRIP12 causes intellectual disability with or without autism spectrum disorders, speech delay, and dysmorphic features.}, journal = {Hum Genet}, volume = {136}, year = {2017}, month = {2017 04}, pages = {377-386}, abstract = {

Impairment of ubiquitin-proteasome system activity involving ubiquitin ligase genes UBE3A, UBE3B, and HUWE1 and deubiquitinating enzyme genes USP7 and USP9X has been reported in patients with neurodevelopmental delays. To date, only a handful of single-nucleotide variants (SNVs) and copy-number variants (CNVs) involving TRIP12, encoding a member of the HECT domain E3 ubiquitin ligases family on chromosome 2q36.3 have been reported. Using chromosomal microarray analysis and whole-exome sequencing (WES), we have identified, respectively, five deletion CNVs and four inactivating SNVs (two frameshifts, one missense, and one splicing) in TRIP12. Seven of these variants were found to be de novo; parental studies could not be completed in two families. Quantitative PCR analyses of the splicing mutation showed a dramatically decreased level of TRIP12 mRNA in the proband compared to the family controls, indicating a loss-of-function mechanism. The shared clinical features include intellectual disability with or without autistic spectrum disorders, speech delay, and facial dysmorphism. Our findings demonstrate that E3 ubiquitin ligase TRIP12 plays an important role in nervous system development and function. The nine presented pathogenic variants further document that TRIP12 haploinsufficiency causes a childhood-onset neurodevelopmental disorder. Finally, our data enable expansion of the phenotypic spectrum of ubiquitin-proteasome dependent disorders.

}, keywords = {Adolescent, Autism Spectrum Disorder, Carrier Proteins, Child, Child, Preschool, Cohort Studies, DNA Copy Number Variations, Facies, Female, Haploinsufficiency, Humans, Infant, Intellectual Disability, Language Development Disorders, Male, Ubiquitin-Protein Ligases}, issn = {1432-1203}, doi = {10.1007/s00439-017-1763-1}, author = {Zhang, Jing and Gambin, Tomasz and Yuan, Bo and Szafranski, Przemyslaw and Rosenfeld, Jill A and Balwi, Mohammed Al and Alswaid, Abdulrahman and Al-Gazali, Lihadh and Shamsi, Aisha M Al and Komara, Makanko and Ali, Bassam R and Roeder, Elizabeth and McAuley, Laura and Roy, Daniel S and Manchester, David K and Magoulas, Pilar and King, Lauren E and Hannig, Vickie and Bonneau, Dominique and Denomm{\'e}-Pichon, Anne-Sophie and Charif, Majida and Besnard, Thomas and B{\'e}zieau, St{\'e}phane and Cogn{\'e}, Benjamin and Andrieux, Joris and Zhu, Wenmiao and He, Weimin and Vetrini, Francesco and Ward, Patricia A and Cheung, Sau Wai and Bi, Weimin and Eng, Christine M and Lupski, James R and Yang, Yaping and Patel, Ankita and Lalani, Seema R and Xia, Fan and Stankiewicz, Pawe{\l}} } @article {391, title = {Heterozygous variants in ACTL6A, encoding a component of the BAF complex, are associated with intellectual disability.}, journal = {Hum Mutat}, volume = {38}, year = {2017}, month = {2017 10}, pages = {1365-1371}, abstract = {

Pathogenic variants in genes encoding components of the BRG1-associated factor (BAF) chromatin remodeling complex have been associated with intellectual disability syndromes. We identified heterozygous, novel variants in ACTL6A, a gene encoding a component of the BAF complex, in three subjects with varying degrees of intellectual disability. Two subjects have missense variants affecting highly conserved amino acid residues within the actin-like domain. Missense mutations in the homologous region in yeast actin were previously reported to be dominant lethal and were associated with impaired binding of the human ACTL6A to β-actin and BRG1. A third subject has a splicing variant that creates an in-frame deletion. Our findings suggest that the variants identified in our subjects may have a deleterious effect on the function of the protein by disturbing the integrity of the BAF complex. Thus, ACTL6A gene mutation analysis should be considered in patients with intellectual disability, learning disabilities, or developmental language disorder.

}, keywords = {Actins, Adolescent, Child, Chromatin Assembly and Disassembly, Chromosomal Proteins, Non-Histone, DNA Helicases, DNA-Binding Proteins, Exome, Face, Female, Hand Deformities, Congenital, Heterozygote, Humans, Intellectual Disability, Male, Micrognathism, Multiprotein Complexes, Mutation, Missense, Nuclear Proteins, Protein Binding, Transcription Factors}, issn = {1098-1004}, doi = {10.1002/humu.23282}, author = {Marom, Ronit and Jain, Mahim and Burrage, Lindsay C and Song, I-Wen and Graham, Brett H and Brown, Chester W and Stevens, Servi J C and Stegmann, Alexander P A and Gunter, Andrew T and Kaplan, Julie D and Gavrilova, Ralitza H and Shinawi, Marwan and Rosenfeld, Jill A and Bae, Yangjin and Tran, Alyssa A and Chen, Yuqing and Lu, James T and Gibbs, Richard A and Eng, Christine and Yang, Yaping and Rousseau, Justine and de Vries, Bert B A and Campeau, Philippe M and Lee, Brendan} } @article {453, title = {High Rate of Recurrent De Novo Mutations in Developmental and Epileptic Encephalopathies.}, journal = {Am J Hum Genet}, volume = {101}, year = {2017}, month = {2017 Nov 02}, pages = {664-685}, abstract = {

Developmental and epileptic encephalopathy (DEE) is a group of conditions characterized by the co-occurrence of epilepsy and intellectual disability (ID), typically with developmental plateauing or regression associated with frequent epileptiform activity. The cause of DEE remains unknown in the majority of cases. We performed whole-genome sequencing (WGS) in 197 individuals with unexplained DEE and pharmaco-resistant seizures and in their unaffected parents. We focused our attention on de novo mutations (DNMs) and identified candidate genes containing such variants. We sought to identify additional subjects with DNMs in these genes by performing targeted sequencing in another series of individuals with DEE and by mining various sequencing datasets. We also performed meta-analyses to document enrichment of DNMs in candidate genes by leveraging our WGS dataset with those of several DEE and ID series. By combining these strategies, we were able to provide a causal link between DEE and the following genes: NTRK2, GABRB2, CLTC, DHDDS, NUS1, RAB11A, GABBR2, and SNAP25. Overall, we established a molecular diagnosis in 63/197 (32\%) individuals in our WGS series. The main cause of DEE in these individuals was de novo point mutations (53/63 solved cases), followed by inherited mutations (6/63 solved cases) and de novo CNVs (4/63 solved cases). De novo missense variants explained a larger proportion of individuals in our series than in other series that were primarily ascertained because of ID. Moreover, these DNMs were more frequently recurrent than those identified in ID series. These observations indicate that the genetic landscape of DEE might be different from that of ID without epilepsy.

}, keywords = {Brain Diseases, Child, Child, Preschool, Epilepsy, Female, Genome, Human, Genome-Wide Association Study, Humans, Intellectual Disability, Male, Mutation, Recurrence, Seizures}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.09.008}, author = {Hamdan, Fadi F and Myers, Candace T and Cossette, Patrick and Lemay, Philippe and Spiegelman, Dan and Laporte, Alexandre Dionne and Nassif, Christina and Diallo, Ousmane and Monlong, Jean and Cadieux-Dion, Maxime and Dobrzeniecka, Sylvia and Meloche, Caroline and Retterer, Kyle and Cho, Megan T and Rosenfeld, Jill A and Bi, Weimin and Massicotte, Christine and Miguet, Marguerite and Brunga, Ledia and Regan, Brigid M and Mo, Kelly and Tam, Cory and Schneider, Amy and Hollingsworth, Georgie and FitzPatrick, David R and Donaldson, Alan and Canham, Natalie and Blair, Edward and Kerr, Bronwyn and Fry, Andrew E and Thomas, Rhys H and Shelagh, Joss and Hurst, Jane A and Brittain, Helen and Blyth, Moira and Lebel, Robert Roger and Gerkes, Erica H and Davis-Keppen, Laura and Stein, Quinn and Chung, Wendy K and Dorison, Sara J and Benke, Paul J and Fassi, Emily and Corsten-Janssen, Nicole and Kamsteeg, Erik-Jan and Mau-Them, Frederic T and Bruel, Ange-Line and Verloes, Alain and {\~O}unap, Katrin and Wojcik, Monica H and Albert, Dara V F and Venkateswaran, Sunita and Ware, Tyson and Jones, Dean and Liu, Yu-Chi and Mohammad, Shekeeb S and Bizargity, Peyman and Bacino, Carlos A and Leuzzi, Vincenzo and Martinelli, Simone and Dallapiccola, Bruno and Tartaglia, Marco and Blumkin, Lubov and Wierenga, Klaas J and Purcarin, Gabriela and O{\textquoteright}Byrne, James J and Stockler, Sylvia and Lehman, Anna and Keren, Boris and Nougues, Marie-Christine and Mignot, Cyril and Auvin, St{\'e}phane and Nava, Caroline and Hiatt, Susan M and Bebin, Martina and Shao, Yunru and Scaglia, Fernando and Lalani, Seema R and Frye, Richard E and Jarjour, Imad T and Jacques, St{\'e}phanie and Boucher, Renee-Myriam and Riou, Emilie and Srour, Myriam and Carmant, Lionel and Lortie, Anne and Major, Philippe and Diadori, Paola and Dubeau, Fran{\c c}ois and D{\textquoteright}Anjou, Guy and Bourque, Guillaume and Berkovic, Samuel F and Sadleir, Lynette G and Campeau, Philippe M and Kibar, Zoha and Lafreni{\`e}re, Ronald G and Girard, Simon L and Mercimek-Mahmutoglu, Saadet and Boelman, Cyrus and Rouleau, Guy A and Scheffer, Ingrid E and Mefford, Heather C and Andrade, Danielle M and Rossignol, Elsa and Minassian, Berge A and Michaud, Jacques L} } @article {359, title = {Kaufman oculo-cerebro-facial syndrome in a child with small and absent terminal phalanges and absent nails.}, journal = {J Hum Genet}, volume = {62}, year = {2017}, month = {2017 Apr}, pages = {465-471}, abstract = {

Kaufman oculo-cerebro-facial syndrome (KOS) is caused by recessive UBE3B mutations and presents with microcephaly, ocular abnormalities, distinctive facial morphology, low cholesterol levels and intellectual disability. We describe a child with microcephaly, brachycephaly, hearing loss, ptosis, blepharophimosis, hypertelorism, cleft palate, multiple renal cysts, absent nails, small or absent terminal phalanges, absent speech and intellectual disability. Syndromes that were initially considered include DOORS syndrome, Coffin-Siris syndrome and Dubowitz syndrome. Clinical investigations coupled with karyotype analysis, array-comparative genomic hybridization, exome and Sanger sequencing were performed to characterize the condition in this child. Sanger sequencing was negative for the DOORS syndrome gene TBC1D24 but exome sequencing identified a homozygous deletion in UBE3B (NM_183415:c.3139_3141del, p.1047_1047del) located within the terminal portion of the HECT domain. This finding coupled with the presence of characteristic features such as brachycephaly, ptosis, blepharophimosis, hypertelorism, short palpebral fissures, cleft palate and developmental delay allowed us to make a diagnosis of KOS. In conclusion, our findings highlight the importance of considering KOS as a differential diagnosis for patients under evaluation for DOORS syndrome and expand the phenotype of KOS to include small or absent terminal phalanges, nails, and the presence of hallux varus and multicystic dysplastic kidneys.

}, keywords = {Abnormalities, Multiple, Adult, Carrier Proteins, Child, Child, Preschool, Diagnosis, Differential, Eczema, Eye Abnormalities, Face, Facies, Female, Growth Disorders, Hand Deformities, Congenital, Humans, Intellectual Disability, Karyotype, Limb Deformities, Congenital, Male, Microcephaly, Micrognathism, Mutation, Neck, Pathology, Molecular, Sequence Analysis, DNA, Ubiquitin-Protein Ligases}, issn = {1435-232X}, doi = {10.1038/jhg.2016.151}, author = {Kariminejad, Ariana and Ajeawung, Norbert Fonya and Bozorgmehr, Bita and Dionne-Laporte, Alexandre and Molidperee, Sirinart and Najafi, Kimia and Gibbs, Richard A and Lee, Brendan H and Hennekam, Raoul C and Campeau, Philippe M} } @article {338, title = {Mutations in EBF3 Disturb Transcriptional Profiles and Cause Intellectual Disability, Ataxia, and Facial Dysmorphism.}, journal = {Am J Hum Genet}, volume = {100}, year = {2017}, month = {2017 Jan 05}, pages = {117-127}, abstract = {

From a GeneMatcher-enabled international collaboration, we identified ten individuals affected by intellectual disability, speech delay, ataxia, and facial dysmorphism and carrying a deleterious EBF3 variant detected by whole-exome sequencing. One 9-bp duplication and one splice-site, five missense, and two nonsense variants in EBF3 were found; the mutations occurred de novo in eight individuals, and the missense variant c.625C>T (p.Arg209Trp) was inherited by two affected siblings from their healthy mother, who is mosaic. EBF3 belongs to the early B cell factor family (also known as Olf, COE, or O/E) and is a transcription factor involved in neuronal differentiation and maturation. Structural assessment predicted that the five amino acid substitutions have damaging effects on DNA binding of EBF3. Transient expression of EBF3 mutant proteins in HEK293T cells revealed mislocalization of all but one mutant in the cytoplasm, as well as nuclear localization. By transactivation assays, all EBF3 mutants showed significantly reduced or no ability to activate transcription of the reporter gene CDKN1A, and in~situ subcellular fractionation experiments demonstrated that EBF3 mutant proteins were less tightly associated with chromatin. Finally, in RNA-seq and ChIP-seq experiments, EBF3 acted as a transcriptional regulator, and mutant EBF3 had reduced genome-wide DNA binding and gene-regulatory activity. Our findings demonstrate that variants disrupting EBF3-mediated transcriptional regulation cause intellectual disability and developmental delay and are present in \~{}0.1\% of individuals with unexplained neurodevelopmental disorders.

}, keywords = {Adolescent, Adult, Amino Acid Substitution, Ataxia, Child, Child, Preschool, Chromatin, Cyclin-Dependent Kinase Inhibitor p21, Developmental Disabilities, Exome, Face, Female, Gene Expression Regulation, Genes, Reporter, HEK293 Cells, Humans, Intellectual Disability, Language Development Disorders, Male, Models, Molecular, Mosaicism, Mutation, Neurodevelopmental Disorders, Protein Transport, Syndrome, Transcription Factors, Transcription, Genetic}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.11.012}, author = {Harms, Frederike Leonie and Girisha, Katta M and Hardigan, Andrew A and Kort{\"u}m, Fanny and Shukla, Anju and Alawi, Malik and Dalal, Ashwin and Brady, Lauren and Tarnopolsky, Mark and Bird, Lynne M and Ceulemans, Sophia and Bebin, Martina and Bowling, Kevin M and Hiatt, Susan M and Lose, Edward J and Primiano, Michelle and Chung, Wendy K and Juusola, Jane and Akdemir, Zeynep C and Bainbridge, Matthew and Charng, Wu-Lin and Drummond-Borg, Margaret and Eldomery, Mohammad K and El-Hattab, Ayman W and Saleh, Mohammed A M and B{\'e}zieau, St{\'e}phane and Cogn{\'e}, Benjamin and Isidor, Bertrand and K{\"u}ry, S{\'e}bastien and Lupski, James R and Myers, Richard M and Cooper, Gregory M and Kutsche, Kerstin} } @article {396, title = {A novel mutation in GMPPA in siblings with apparent intellectual disability, epilepsy, dysmorphism, and autonomic dysfunction.}, journal = {Am J Med Genet A}, volume = {173}, year = {2017}, month = {2017 Aug}, pages = {2246-2250}, abstract = {

GMPPA encodes the GDP-mannose pyrophosphorylase A protein (GMPPA). The function of GMPPA is not well defined, however it is a homolog of GMPPB which catalyzes the reaction that converts mannose-1-phosphate and guanosine-5{\textquoteright}-triphosphate to GDP-mannose. Previously, biallelic mutations in GMPPA were reported to cause a disorder characterized by achalasia, alacrima, neurological deficits, and intellectual disability. In this study, we report a female proband with achalasia, alacrima, hypohydrosis, apparent intellectual disability, seizures, microcephaly, esotropia, and craniofacial dysmorphism. Exome sequencing identified a previously unreported homozygous c.853+1G>A variant in GMPPA in the proband and her affected sister. Their unaffected parents were heterozygous, and unaffected brother homozygous wild type for this variant. Lymphoblast cells from the affected sisters showed complete loss of the GMPPA protein by Western blotting, and increased levels of GDP-mannose in lymphoblasts on high performance liquid chromatography. Based on our findings and the previous report describing patients with an overlapping phenotype, we conclude that this novel variant in GMPPA, identified by exome sequencing in the proband and her affected sister, is the genetic cause of their phenotype and may expand the known phenotype of this recently described glycosylation disorder.

}, keywords = {Abnormalities, Multiple, Child, Child, Preschool, Craniofacial Abnormalities, Epilepsy, Exome, Facies, Female, Heterozygote, Humans, Intellectual Disability, Microcephaly, Muscular Atrophy, Mutation, Missense, Nucleotidyltransferases, Pedigree, Phenotype, Seizures}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38292}, author = {Gold, Wendy A and Sobreira, Nara and Wiame, Elsa and Marbaix, Alexandre and Van Schaftingen, Emile and Franzka, Patricia and Riley, Lisa G and Worgan, Lisa and H{\"u}bner, Christian A and Christodoulou, John and Ad{\`e}s, Lesley C} } @article {442, title = {Phenotypic and molecular characterisation of CDK13-related congenital heart defects, dysmorphic facial features and intellectual developmental disorders.}, journal = {Genome Med}, volume = {9}, year = {2017}, month = {2017 08 14}, pages = {73}, abstract = {

BACKGROUND: De novo missense variants in CDK13 have been described as the cause of syndromic congenital heart defects in seven individuals ascertained from a large congenital cardiovascular malformations cohort. We aimed to further define the phenotypic and molecular spectrum of this newly described disorder.

METHODS: To minimise ascertainment bias, we recruited nine additional individuals with CDK13 pathogenic variants from clinical and research exome laboratory sequencing cohorts. Each individual underwent dysmorphology exam and comprehensive medical history review.

RESULTS: We demonstrate greater than expected phenotypic heterogeneity, including 33\% (3/9) of individuals without structural heart disease on echocardiogram. There was a high penetrance for a unique constellation of facial dysmorphism and global developmental delay, as well as less frequently seen renal and sacral anomalies. Two individuals had novel CDK13 variants (p.Asn842Asp, p.Lys734Glu), while the remaining seven unrelated individuals had a recurrent, previously published p.Asn842Ser variant. Summary of all variants published to date demonstrates apparent restriction of pathogenic variants to the protein kinase domain with clustering in the ATP and magnesium binding sites.

CONCLUSIONS: Here we provide detailed phenotypic and molecular characterisation of individuals with pathogenic variants in CDK13 and propose management guidelines based upon the estimated prevalence of anomalies identified.

}, keywords = {Adolescent, Adult, CDC2 Protein Kinase, Child, Child, Preschool, Face, Female, Heart Defects, Congenital, Humans, Infant, Intellectual Disability, Male, Mutation, Phenotype, Syndrome}, issn = {1756-994X}, doi = {10.1186/s13073-017-0463-8}, author = {Bostwick, Bret L and McLean, Scott and Posey, Jennifer E and Streff, Haley E and Gripp, Karen W and Blesson, Alyssa and Powell-Hamilton, Nina and Tusi, Jessica and Stevenson, David A and Farrelly, Ellyn and Hudgins, Louanne and Yang, Yaping and Xia, Fan and Wang, Xia and Liu, Pengfei and Walkiewicz, Magdalena and McGuire, Marianne and Grange, Dorothy K and Andrews, Marisa V and Hummel, Marybeth and Madan-Khetarpal, Suneeta and Infante, Elena and Coban-Akdemir, Zeynep and Miszalski-Jamka, Karol and Jefferies, John L and Rosenfeld, Jill A and Emrick, Lisa and Nugent, Kimberly M and Lupski, James R and Belmont, John W and Lee, Brendan and Lalani, Seema R} } @article {334, title = {A Recurrent De Novo Variant in NACC1 Causes a Syndrome Characterized by Infantile Epilepsy, Cataracts, and Profound Developmental Delay.}, journal = {Am J Hum Genet}, volume = {100}, year = {2017}, month = {2017 Feb 02}, pages = {343-351}, abstract = {

Whole-exome sequencing (WES) has increasingly enabled new pathogenic gene variant identification for undiagnosed neurodevelopmental disorders and provided insights into both gene function and disease biology. Here, we describe seven children with a neurodevelopmental disorder characterized by microcephaly, profound developmental delays and/or intellectual disability, cataracts, severe epilepsy including infantile spasms, irritability, failure to thrive, and stereotypic hand movements. Brain imaging in these individuals reveals delay in myelination and cerebral atrophy. We observe an identical recurrent de novo heterozygous c.892C>T (p.Arg298Trp) variant in the nucleus accumbens associated 1 (NACC1) gene in seven affected individuals. One of the seven individuals is mosaic for this variant. NACC1 encodes a transcriptional repressor implicated in gene expression and has not previously been associated with germline disorders. The probability of finding the same missense NACC1 variant by chance in 7 out of 17,228 individuals who~underwent WES for diagnoses of neurodevelopmental phenotypes is extremely small and achieves genome-wide significance (p~= 1.25~{\texttimes} 10). Selective constraint against missense variants in NACC1 makes this excess of an identical missense variant in all seven individuals more remarkable. Our findings are consistent with a germline recurrent mutational hotspot associated with an allele-specific neurodevelopmental phenotype in NACC1.

}, keywords = {Alleles, Amino Acid Sequence, Brain, Cataract, Child, Child, Preschool, Female, Genetic Variation, Genome-Wide Association Study, Humans, Infant, Intellectual Disability, Magnetic Resonance Imaging, Male, Microcephaly, Mutation, Missense, Neoplasm Proteins, Pedigree, Phenotype, Repressor Proteins, Spasms, Infantile}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.12.013}, author = {Schoch, Kelly and Meng, Linyan and Szelinger, Szabolcs and Bearden, David R and Stray-Pedersen, Asbjorg and Busk, Oyvind L and Stong, Nicholas and Liston, Eriskay and Cohn, Ronald D and Scaglia, Fernando and Rosenfeld, Jill A and Tarpinian, Jennifer and Skraban, Cara M and Deardorff, Matthew A and Friedman, Jeremy N and Akdemir, Zeynep Coban and Walley, Nicole and Mikati, Mohamad A and Kranz, Peter G and Jasien, Joan and McConkie-Rosell, Allyn and McDonald, Marie and Wechsler, Stephanie Burns and Freemark, Michael and Kansagra, Sujay and Freedman, Sharon and Bali, Deeksha and Millan, Francisca and Bale, Sherri and Nelson, Stanley F and Lee, Hane and Dorrani, Naghmeh and Goldstein, David B and Xiao, Rui and Yang, Yaping and Posey, Jennifer E and Martinez-Agosto, Julian A and Lupski, James R and Wangler, Michael F and Shashi, Vandana} } @article {99, title = {Biallelic Mutations in UNC80 Cause Persistent Hypotonia, Encephalopathy, Growth Retardation, and Severe Intellectual Disability.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Jan 07}, pages = {202-9}, abstract = {

Ion channel proteins are required for both the establishment of resting membrane potentials and the generation of action potentials. Hundreds of mutations in genes encoding voltage-gated ion channels responsible for action potential generation have been found to cause severe neurological diseases. In contrast, the roles of voltage-independent "leak" channels, important for the establishment and maintenance of resting membrane potentials upon which action potentials are generated, are not well established in human disease. UNC80 is a large component of the NALCN sodium-leak channel complex that regulates the basal excitability of the nervous system. Loss-of-function mutations of NALCN cause infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF). We report four individuals from three unrelated families who have homozygous missense or compound heterozygous truncating mutations in UNC80 and persistent hypotonia, encephalopathy, growth failure, and severe intellectual disability. Compared to control cells, HEK293T cells transfected with an expression plasmid containing the c.5098C>T (p.Pro1700Ser) UNC80 mutation found in one individual showed markedly decreased NALCN channel currents. Our findings demonstrate the fundamental significance of UNC80 and basal ionic conductance to human health.

}, keywords = {Adolescent, Alleles, Brain Diseases, Carrier Proteins, Child, Child, Preschool, Female, Growth Disorders, Humans, Intellectual Disability, Membrane Proteins, Muscle Hypotonia, Mutation, Severity of Illness Index}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.11.004}, author = {Stray-Pedersen, Asbj{\o}rg and Cobben, Jan-Maarten and Prescott, Trine E and Lee, Sora and Cang, Chunlei and Aranda, Kimberly and Ahmed, Sohnee and Alders, Marielle and Gerstner, Thorsten and Aslaksen, Kathinka and T{\'e}treault, Martine and Qin, Wen and Hartley, Taila and Jhangiani, Shalini N and Muzny, Donna M and Tarailo-Graovac, Maja and van Karnebeek, Clara D M and Lupski, James R and Ren, Dejian and Yoon, Grace} } @article {414, title = {De novo missense variants in PPP1CB are associated with intellectual disability and congenital heart disease.}, journal = {Hum Genet}, volume = {135}, year = {2016}, month = {2016 12}, pages = {1399-1409}, abstract = {

Intellectual disabilities are genetically heterogeneous and can be associated with congenital anomalies. Using whole-exome sequencing (WES), we identified five different de novo missense variants in the protein phosphatase-1 catalytic subunit beta (PPP1CB) gene in eight unrelated individuals who share an overlapping phenotype of dysmorphic features, macrocephaly, developmental delay or intellectual disability (ID), congenital heart disease, short stature, and skeletal and connective tissue abnormalities. Protein phosphatase-1 (PP1) is a serine/threonine-specific protein phosphatase involved in the dephosphorylation of a variety of proteins. The PPP1CB gene encodes a PP1 subunit that regulates the level of protein phosphorylation. All five altered amino acids we observed are highly conserved among the PP1 subunit family, and all are predicted to disrupt PP1 subunit binding and impair dephosphorylation. Our data suggest that our heterozygous de novo PPP1CB pathogenic variants are associated with syndromic intellectual disability.

}, keywords = {Adolescent, Adult, Child, Child, Preschool, Exome, Female, Genetic Association Studies, Genetic Predisposition to Disease, Heart Defects, Congenital, Humans, Intellectual Disability, Male, Mutation, Missense, Phosphorylation, Protein Phosphatase 1}, issn = {1432-1203}, doi = {10.1007/s00439-016-1731-1}, author = {Ma, Lijiang and Bayram, Yavuz and McLaughlin, Heather M and Cho, Megan T and Krokosky, Alyson and Turner, Clesson E and Lindstrom, Kristin and Bupp, Caleb P and Mayberry, Katey and Mu, Weiyi and Bodurtha, Joann and Weinstein, Veronique and Zadeh, Neda and Alcaraz, Wendy and Powis, Z{\"o}e and Shao, Yunru and Scott, Daryl A and Lewis, Andrea M and White, Janson J and Jhangiani, Shalani N and Gulec, Elif Yilmaz and Lalani, Seema R and Lupski, James R and Retterer, Kyle and Schnur, Rhonda E and Wentzensen, Ingrid M and Bale, Sherri and Chung, Wendy K} } @article {28, title = {De Novo Mutations in SON Disrupt RNA Splicing of Genes Essential for Brain Development and Metabolism, Causing an Intellectual-Disability Syndrome.}, journal = {Am J Hum Genet}, volume = {99}, year = {2016}, month = {2016 Sep 01}, pages = {711-719}, abstract = {

The overall understanding of the molecular etiologies of intellectual disability (ID) and developmental delay (DD) is increasing as next-generation sequencing technologies identify genetic variants in individuals with such disorders. However, detailed analyses conclusively confirming these variants, as well as the underlying molecular mechanisms explaining the diseases, are often lacking. Here, we report on an ID syndrome caused by de novo heterozygous loss-of-function (LoF) mutations in SON. The syndrome is characterized by ID and/or DD, malformations of the cerebral cortex, epilepsy, vision problems, musculoskeletal abnormalities, and congenital malformations. Knockdown of son in zebrafish resulted in severe malformation of the spine, brain, and eyes. Importantly, analyses of RNA from affected individuals revealed that genes critical for neuronal migration and cortex organization (TUBG1, FLNA, PNKP, WDR62, PSMD3, and~HDAC6) and metabolism (PCK2, PFKL, IDH2, ACY1, and ADA) are significantly downregulated because of the accumulation of mis-spliced transcripts resulting from erroneous SON-mediated RNA splicing. Our data highlight SON as a master regulator governing neurodevelopment and demonstrate the importance of SON-mediated RNA splicing in human development.

}, keywords = {Animals, Brain, Developmental Disabilities, DNA-Binding Proteins, Eye Abnormalities, Female, Genes, Essential, Haploinsufficiency, Head, Heterozygote, Humans, Intellectual Disability, Male, Metabolic Diseases, Minor Histocompatibility Antigens, Mutation, Pedigree, RNA Splicing, RNA, Messenger, Spine, Syndrome, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.06.029}, author = {Kim, Jung-Hyun and Shinde, Deepali N and Reijnders, Margot R F and Hauser, Natalie S and Belmonte, Rebecca L and Wilson, Gregory R and Bosch, Dani{\"e}lle G M and Bubulya, Paula A and Shashi, Vandana and Petrovski, Slav{\'e} and Stone, Joshua K and Park, Eun Young and Veltman, Joris A and Sinnema, Margje and Stumpel, Connie T R M and Draaisma, Jos M and Nicolai, Joost and Yntema, Helger G and Lindstrom, Kristin and de Vries, Bert B A and Jewett, Tamison and Santoro, Stephanie L and Vogt, Julie and Bachman, Kristine K and Seeley, Andrea H and Krokosky, Alyson and Turner, Clesson and Rohena, Luis and Hempel, Maja and Kort{\"u}m, Fanny and Lessel, Davor and Neu, Axel and Strom, Tim M and Wieczorek, Dagmar and Bramswig, Nuria and Laccone, Franco A and Behunova, Jana and Rehder, Helga and Gordon, Christopher T and Rio, Marl{\`e}ne and Romana, Serge and Tang, Sha and El-Khechen, Dima and Cho, Megan T and McWalter, Kirsty and Douglas, Ganka and Baskin, Berivan and Begtrup, Amber and Funari, Tara and Schoch, Kelly and Stegmann, Alexander P A and Stevens, Servi J C and Zhang, Dong-Er and Traver, David and Yao, Xu and MacArthur, Daniel G and Brunner, Han G and Mancini, Grazia M and Myers, Richard M and Owen, Laurie B and Lim, Ssang-Taek and Stachura, David L and Vissers, Lisenka E L M and Ahn, Eun-Young Erin} } @article {100, title = {Expansion of the spectrum of ITGB6-related disorders to adolescent alopecia, dentogingival abnormalities and intellectual disability.}, journal = {Eur J Hum Genet}, volume = {24}, year = {2016}, month = {2016 08}, pages = {1223-7}, abstract = {

Alopecia with mental retardation (APMR) is a very rare disorder. In this study, we report on a consanguineous Pakistani family (AP91) with mild-to-moderate intellectual disability, adolescent alopecia and dentogingival abnormalities. Using homozygosity mapping, linkage analysis and exome sequencing, we identified a novel rare missense variant c.898G>A (p.(Glu300Lys)) in ITGB6, which co-segregates with the phenotype within the family and is predicted to be deleterious. Structural modeling shows that Glu300 lies in the β-propeller domain, and is surrounded by several residues that are important for heterodimerization with α integrin. Previous studies showed that ITGB6 variants can cause amelogenesis imperfecta in humans, but patients from family AP91 who are homozygous for the c.898G>A variant present with neurological and dermatological features, indicating a role for ITGB6 beyond enamel formation. Our study demonstrates that a rare deleterious variant within ITGB6 causes not only dentogingival anomalies but also intellectual disability and alopecia.

}, keywords = {Adolescent, Adult, Alopecia, Child, Female, Humans, Integrin beta Chains, Intellectual Disability, Male, Mutation, Missense, Pedigree, Phenotype, Protein Domains, Syndrome, Tooth Abnormalities}, issn = {1476-5438}, doi = {10.1038/ejhg.2015.260}, author = {Ansar, Muhammad and Jan, Abid and Santos-Cortez, Regie Lyn P and Wang, Xin and Suliman, Muhammad and Acharya, Anushree and Habib, Rabia and Abbe, Izoduwa and Ali, Ghazanfar and Lee, Kwanghyuk and Smith, Joshua D and Nickerson, Deborah A and Shendure, Jay and Bamshad, Michael J and Ahmad, Wasim and Leal, Suzanne M} } @article {65, title = {Germline De Novo Mutations in GNB1 Cause Severe Neurodevelopmental Disability, Hypotonia, and Seizures.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 05 05}, pages = {1001-1010}, abstract = {

Whole-exome sequencing of 13 individuals with developmental delay commonly accompanied by abnormal muscle tone and seizures identified de novo missense mutations enriched within a sub-region of GNB1, a gene encoding the guanine nucleotide-binding protein~subunit beta-1, Gβ. These 13 individuals were identified among a base of 5,855 individuals recruited for various undiagnosed genetic disorders. The probability of observing 13 or more de novo mutations by chance among 5,855 individuals is very low (p~=~7.1~{\texttimes} 10(-21)), implicating GNB1 as a genome-wide-significant disease-associated gene. The majority of these 13 mutations affect known Gβ binding sites, which suggests that a likely disease mechanism is through the disruption of the protein interface required for Gα-Gβγ interaction (resulting in a constitutively active Gβγ) or through the disruption of residues relevant for interaction between Gβγ and certain downstream effectors (resulting in reduced interaction with the effectors). Strikingly, 8 of the 13 individuals recruited here for a neurodevelopmental disorder have a germline de novo GNB1 mutation that overlaps a set of five recurrent somatic tumor mutations for which recent functional studies demonstrated a gain-of-function effect due to constitutive activation of G protein downstream signaling cascades for some of the affected residues.

}, keywords = {Adolescent, Adult, Child, Child, Preschool, Developmental Disabilities, Exome, Female, Germ-Line Mutation, GTP-Binding Protein beta Subunits, Humans, Infant, Intellectual Disability, Male, Muscle Hypotonia, Phenotype, Protein Conformation, Seizures, Signal Transduction, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.03.011}, author = {Petrovski, Slav{\'e} and K{\"u}ry, S{\'e}bastien and Myers, Candace T and Anyane-Yeboa, Kwame and Cogn{\'e}, Benjamin and Bialer, Martin and Xia, Fan and Hemati, Parisa and Riviello, James and Mehaffey, Michele and Besnard, Thomas and Becraft, Emily and Wadley, Alexandrea and Politi, Anya Revah and Colombo, Sophie and Zhu, Xiaolin and Ren, Zhong and Andrews, Ian and Dudding-Byth, Tracy and Schneider, Amy L and Wallace, Geoffrey and Rosen, Aaron B I and Schelley, Susan and Enns, Gregory M and Corre, Pierre and Dalton, Joline and Mercier, Sandra and Latypova, X{\'e}nia and Schmitt, S{\'e}bastien and Guzman, Edwin and Moore, Christine and Bier, Louise and Heinzen, Erin L and Karachunski, Peter and Shur, Natasha and Grebe, Theresa and Basinger, Alice and Nguyen, Joanne M and B{\'e}zieau, St{\'e}phane and Wierenga, Klaas and Bernstein, Jonathan A and Scheffer, Ingrid E and Rosenfeld, Jill A and Mefford, Heather C and Isidor, Bertrand and Goldstein, David B} } @article {126, title = {Gonadal mosaicism in ARID1B gene causes intellectual disability and dysmorphic features in three siblings.}, journal = {Am J Med Genet A}, volume = {170A}, year = {2016}, month = {2016 Jan}, pages = {156-61}, abstract = {

The gene encoding the AT-rich interaction domain-containing protein 1B (ARID1B) has recently been shown to be one of the most frequently mutated genes in patients with intellectual disability (ID). The phenotypic spectrums associated with variants in this gene vary widely ranging for mild to severe non-specific ID to Coffin-Siris syndrome. In this study, we evaluated three children from a consanguineous Emirati family affected with ID and dysmorphic features. Genomic DNA from all affected siblings was analyzed using CGH array and whole-exome sequencing (WES). Based on a recessive mode of inheritance, homozygous or compound heterozygous variants shared among all three affected children could not be identified. However, further analysis revealed a heterozygous variant (c.4318C>T; p.Q1440*) in the three affected children in an autosomal dominant ID causing gene, ARID1B. This variant was absent in peripheral blood samples obtained from both parents and unaffected siblings. Therefore, we propose that the most likely explanation for this situation is that one of the parents is a gonadal mosaic for the variant. To the best of our knowledge, this is the first report of a gonadal mosaicism inheritance of an ARID1B variant leading to familial ID recurrence.

}, keywords = {Abnormalities, Multiple, Adolescent, Child, DNA-Binding Proteins, Exome, Face, Female, Hand Deformities, Congenital, Heterozygote, Humans, Intellectual Disability, Male, Micrognathism, Mosaicism, Mutation, Neck, Pedigree, Siblings, Transcription Factors}, issn = {1552-4833}, doi = {10.1002/ajmg.a.37405}, author = {Ben-Salem, Salma and Sobreira, Nara and Akawi, Nadia A and Al-Shamsi, Aisha M and John, Anne and Pramathan, Thachillath and Valle, David and Ali, Bassam R and Al-Gazali, Lihadh} } @article {59, title = {Identification of Intellectual Disability Genes in Female Patients with a Skewed X-Inactivation Pattern.}, journal = {Hum Mutat}, volume = {37}, year = {2016}, month = {2016 08}, pages = {804-11}, abstract = {

Intellectual disability (ID) is a heterogeneous disorder with an unknown molecular etiology in many cases. Previously, X-linked ID (XLID) studies focused on males because of the hemizygous state of their X chromosome. Carrier females are generally unaffected because of the presence of a second normal allele, or inactivation of the mutant X chromosome in most of their cells (skewing). However, in female ID patients, we hypothesized that the presence of skewing of X-inactivation would be an indicator for an X chromosomal ID cause. We analyzed the X-inactivation patterns of 288 females with ID, and found that 22 (7.6\%) had extreme skewing (>90\%), which is significantly higher than observed in the general population (3.6\%; P~=~0.029). Whole-exome sequencing of 19 females with extreme skewing revealed causal variants in six females in the XLID genes DDX3X, NHS, WDR45, MECP2, and SMC1A. Interestingly, variants in genes escaping X-inactivation presumably cause both XLID and skewing of X-inactivation in three of these patients. Moreover, variants likely accounting for skewing only were detected in MED12, HDAC8, and TAF9B. All tested candidate causative variants were de novo events. Hence, extreme skewing is a good indicator for the presence of X-linked variants in female patients.

}, keywords = {Carrier Proteins, Cell Cycle Proteins, Chromosomal Proteins, Non-Histone, DEAD-box RNA Helicases, Exome, Female, Genetic Variation, Humans, Intellectual Disability, Methyl-CpG-Binding Protein 2, Nuclear Proteins, Sequence Analysis, DNA, X Chromosome Inactivation}, issn = {1098-1004}, doi = {10.1002/humu.23012}, author = {Fieremans, Nathalie and Van Esch, Hilde and Holvoet, Maureen and Van Goethem, Gert and Devriendt, Koenraad and Rosello, Monica and Mayo, Sonia and Martinez, Francisco and Jhangiani, Shalini and Muzny, Donna M and Gibbs, Richard A and Lupski, James R and Vermeesch, Joris R and Marynen, Peter and Froyen, Guy} } @article {23, title = {Mutations in MBOAT7, Encoding Lysophosphatidylinositol Acyltransferase I, Lead to Intellectual Disability Accompanied by Epilepsy and Autistic Features.}, journal = {Am J Hum Genet}, volume = {99}, year = {2016}, month = {2016 Oct 06}, pages = {912-916}, abstract = {

The risk of epilepsy among individuals with intellectual disability (ID) is approximately ten times that of the general population. From a cohort of >5,000 families affected by neurodevelopmental disorders, we identified six consanguineous families harboring homozygous inactivating variants in MBOAT7, encoding lysophosphatidylinositol acyltransferase (LPIAT1). Subjects presented with ID frequently accompanied by epilepsy and autistic features. LPIAT1 is a membrane-bound phospholipid-remodeling enzyme that transfers arachidonic acid (AA) to lysophosphatidylinositol to produce AA-containing phosphatidylinositol. This study suggests a role for AA-containing phosphatidylinositols in the development of ID accompanied by epilepsy and autistic features.

}, keywords = {Acyltransferases, Arachidonic Acid, Autistic Disorder, Child, Child, Preschool, Consanguinity, Epilepsy, Female, Homozygote, Humans, Infant, Intellectual Disability, Lysophospholipids, Male, Membrane Proteins, Mutation, Pedigree, Phosphatidylinositols}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.07.019}, author = {Johansen, Anide and Rosti, Rasim O and Musaev, Damir and Sticca, Evan and Harripaul, Ricardo and Zaki, Maha and {\c C}a{\u g}layan, Ahmet Okay and Azam, Matloob and Sultan, Tipu and Froukh, Tawfiq and Reis, Andr{\'e} and Popp, Bernt and Ahmed, Iltaf and John, Peter and Ayub, Muhammad and Ben-Omran, Tawfeg and Vincent, John B and Gleeson, Joseph G and Abou Jamra, Rami} } @article {41, title = {Nonrecurrent PMP22-RAI1 contiguous gene deletions arise from replication-based mechanisms and result in Smith-Magenis syndrome with evident peripheral neuropathy.}, journal = {Hum Genet}, volume = {135}, year = {2016}, month = {2016 Oct}, pages = {1161-74}, abstract = {

Hereditary neuropathy with liability to pressure palsies (HNPP) and Smith-Magenis syndrome (SMS) are genomic disorders associated with deletion copy number variants involving chromosome 17p12 and 17p11.2, respectively. Nonallelic homologous recombination (NAHR)-mediated recurrent deletions are responsible for the majority of HNPP and SMS cases; the rearrangement products encompass the key dosage-sensitive genes PMP22 and RAI1, respectively, and result in haploinsufficiency for these genes. Less frequently, nonrecurrent genomic rearrangements occur at this locus. Contiguous gene duplications encompassing both PMP22 and RAI1, i.e., PMP22-RAI1 duplications, have been investigated, and replication-based mechanisms rather than NAHR have been proposed for these rearrangements. In the current study, we report molecular and clinical characterizations of six subjects with the reciprocal phenomenon of deletions spanning both genes, i.e., PMP22-RAI1 deletions. Molecular studies utilizing high-resolution array comparative genomic hybridization and breakpoint junction sequencing identified mutational signatures that were suggestive of replication-based mechanisms. Systematic clinical studies revealed features consistent with SMS, including features of intellectual disability, speech and gross motor delays, behavioral problems and ocular abnormalities. Five out of six subjects presented clinical signs and/or objective electrophysiologic studies of peripheral neuropathy. Clinical profiling may improve the clinical management of this unique group of subjects, as the peripheral neuropathy can be more severe or of earlier onset as compared to SMS patients having the common recurrent deletion. Moreover, the current study, in combination with the previous report of PMP22-RAI1 duplications, contributes to the understanding of rare complex phenotypes involving multiple dosage-sensitive genes from a genetic mechanistic standpoint.

}, keywords = {Adolescent, Adult, Child, Child, Preschool, Chromosomes, Human, Pair 17, DNA Copy Number Variations, DNA Replication, Female, Gene Deletion, Haploinsufficiency, Homologous Recombination, Humans, Intellectual Disability, Male, Mutation, Myelin Proteins, Smith-Magenis Syndrome, Trans-Activators, Transcription Factors}, issn = {1432-1203}, doi = {10.1007/s00439-016-1703-5}, author = {Yuan, Bo and Neira, Juanita and Gu, Shen and Harel, Tamar and Liu, Pengfei and Brice{\~n}o, Ignacio and Elsea, Sarah H and G{\'o}mez, Alberto and Potocki, Lorraine and Lupski, James R} } @article {97, title = {POGZ truncating alleles cause syndromic intellectual disability.}, journal = {Genome Med}, volume = {8}, year = {2016}, month = {2016 Jan 06}, pages = {3}, abstract = {

BACKGROUND: Large-scale cohort-based whole exome sequencing of individuals with neurodevelopmental disorders (NDDs) has identified numerous novel candidate disease genes; however, detailed phenotypic information is often lacking in such studies. De novo mutations in pogo transposable element with zinc finger domain (POGZ) have been identified in six independent and diverse cohorts of individuals with NDDs ranging from autism spectrum disorder to developmental delay.

METHODS: Whole exome sequencing was performed on five unrelated individuals. Sanger sequencing was used to validate variants and segregate mutations with the phenotype in available family members.

RESULTS: We identified heterozygous truncating mutations in POGZ in five unrelated individuals, which were confirmed to be de novo or not present in available parental samples. Careful review of the phenotypes revealed shared features that included developmental delay, intellectual disability, hypotonia, behavioral abnormalities, and similar facial characteristics. Variable features included short stature, microcephaly, strabismus and hearing loss.

CONCLUSIONS: While POGZ has been associated with neurodevelopmental disorders in large cohort studies, our data suggest that loss of function variants in POGZ lead to an identifiable syndrome of NDD with specific phenotypic traits. This study exemplifies the era of human reverse clinical genomics ushered in by large disease-directed cohort studies; first defining a new syndrome molecularly and, only subsequently, phenotypically.

}, keywords = {Adolescent, Adult, Alleles, Child, Preschool, Exome, Female, Heterozygote, Humans, Infant, Intellectual Disability, Male, Mutation, Sequence Analysis, DNA, Transposases}, issn = {1756-994X}, doi = {10.1186/s13073-015-0253-0}, author = {White, Janson and Beck, Christine R and Harel, Tamar and Posey, Jennifer E and Jhangiani, Shalini N and Tang, Sha and Farwell, Kelly D and Powis, Z{\"o}e and Mendelsohn, Nancy J and Baker, Janice A and Pollack, Lynda and Mason, Kati J and Wierenga, Klaas J and Arrington, Daniel K and Hall, Melissa and Psychogios, Apostolos and Fairbrother, Laura and Walkiewicz, Magdalena and Person, Richard E and Niu, Zhiyv and Zhang, Jing and Rosenfeld, Jill A and Muzny, Donna M and Eng, Christine and Beaudet, Arthur L and Lupski, James R and Boerwinkle, Eric and Gibbs, Richard A and Yang, Yaping and Xia, Fan and Sutton, V Reid} } @article {62, title = {A Syndromic Intellectual Disability Disorder Caused by Variants in TELO2, a Gene Encoding a Component of the TTT Complex.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 05 05}, pages = {909-918}, abstract = {

The proteins encoded by TELO2, TTI1, and TTI2 interact to form the TTT complex, a co-chaperone for maturation of the phosphatidylinositol 3-kinase-related protein kinases (PIKKs). Here we report six affected individuals from four families with intellectual disability (ID) and neurological and other congenital abnormalities associated with compound heterozygous variants in TELO2. Although their fibroblasts showed reduced steady-state levels of TELO2 and the other components of the TTT complex, PIKK functions were normal in cellular assays. Our results suggest that these TELO2 missense variants result in loss of function, perturb TTT complex stability, and cause an autosomal-recessive syndromic form of ID.

}, keywords = {Adolescent, Carrier Proteins, Child, Female, Humans, Intellectual Disability, Male, Molecular Chaperones, Pedigree, Phosphatidylinositol 3-Kinases, Protein-Serine-Threonine Kinases, Telomere-Binding Proteins}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.03.014}, author = {You, Jing and Sobreira, Nara L and Gable, Dustin L and Jurgens, Julie and Grange, Dorothy K and Belnap, Newell and Siniard, Ashley and Szelinger, Szabolcs and Schrauwen, Isabelle and Richholt, Ryan F and Vallee, Stephanie E and Dinulos, Mary Beth P and Valle, David and Armanios, Mary and Hoover-Fong, Julie} } @article {413, title = {Whole-exome sequencing identifies novel variants in PNPT1 causing oxidative phosphorylation defects and severe multisystem disease.}, journal = {Eur J Hum Genet}, volume = {25}, year = {2016}, month = {2016 01}, pages = {79-84}, abstract = {

Recent advances in next-generation sequencing strategies have led to the discovery of many novel disease genes. We describe here a non-consanguineous family with two affected boys presenting with early onset of severe axonal neuropathy, optic atrophy, intellectual disability, auditory neuropathy and chronic respiratory and gut disturbances. Whole-exome sequencing (WES) was performed on all family members and we identified compound heterozygous variants (c.[760C>A];[1528G>C];p.[(Gln254Lys);(Ala510Pro)] in the polyribonucleotide nucleotidyltransferase 1 (PNPT1) gene in both affected individuals. PNPT1 encodes the polynucleotide phosphorylase (PNPase) protein, which is involved in the transport of small RNAs into the mitochondria. These RNAs are involved in the mitochondrial translation machinery, responsible for the synthesis of mitochondrially encoded subunits of the oxidative phosphorylation (OXPHOS) complexes. Both PNPT1 variants are within highly conserved regions and predicted to be damaging. These variants resulted in quaternary defects in the PNPase protein and a clear reduction in protein and mRNA expression of PNPT1 in patient fibroblasts compared with control cells. Protein analysis of the OXPHOS complexes showed a significant reduction in complex I (CI), complex III (CIII) and complex IV (CIV). Enzyme activity of CI and CIV was clearly reduced in patient fibroblasts compared with controls along with a 33\% reduction in total mitochondrial protein synthesis. In vitro rescue experiments, using exogenous expression of wild-type PNPT1 in patient fibroblasts, ameliorated the deficiencies in the OXPHOS complex protein expression, supporting the likely pathogenicity of these variants and the importance of WES in efficiently identifying rare genetic disease genes.

}, keywords = {Axons, Exome, Exoribonucleases, High-Throughput Nucleotide Sequencing, Humans, Intellectual Disability, Male, Mitochondria, Mutation, Optic Atrophy, Oxidative Phosphorylation, Pedigree, Protein Structure, Quaternary}, issn = {1476-5438}, doi = {10.1038/ejhg.2016.128}, author = {Alodaib, Ahmad and Sobreira, Nara and Gold, Wendy A and Riley, Lisa G and Van Bergen, Nicole J and Wilson, Meredith J and Bennetts, Bruce and Thorburn, David R and Boehm, Corinne and Christodoulou, John} } @article {184, title = {Cerebral visual impairment and intellectual disability caused by PGAP1 variants.}, journal = {Eur J Hum Genet}, volume = {23}, year = {2015}, month = {2015 Dec}, pages = {1689-93}, abstract = {

Homozygous variants in PGAP1 (post-GPI attachment to proteins 1) have recently been identified in two families with developmental delay, seizures and/or spasticity. PGAP1 is a member of the glycosylphosphatidylinositol anchor biosynthesis and remodeling pathway and defects in this pathway are a subclass of congenital disorders of glycosylation. Here we performed whole-exome sequencing in an individual with cerebral visual impairment (CVI), intellectual disability (ID), and factor XII deficiency and revealed compound heterozygous variants in PGAP1, c.274_276del (p.(Pro92del)) and c.921_925del (p.(Lys308Asnfs*25)). Subsequently, PGAP1-deficient Chinese hamster ovary (CHO)-cell lines were transfected with either mutant or wild-type constructs and their sensitivity to phosphatidylinositol-specific phospholipase C (PI-PLC) treatment was measured. The mutant constructs could not rescue the PGAP1-deficient CHO cell lines resistance to PI-PLC treatment. In addition, lymphoblastoid cell lines (LCLs) of the affected individual showed no sensitivity to PI-PLC treatment, whereas the LCLs of the heterozygous carrier parents were partially resistant. In conclusion, we report novel PGAP1 variants in a boy with CVI and ID and a proven functional loss of PGAP1 and show, to our knowledge, for the first time this genetic association with CVI.

}, keywords = {Animals, Cell Line, Tumor, Child, CHO Cells, Cricetinae, Cricetulus, Humans, Intellectual Disability, Male, Membrane Proteins, Mutation, Phosphoinositide Phospholipase C, Phosphoric Monoester Hydrolases, Syndrome, Vision Disorders, Visual Perception}, issn = {1476-5438}, doi = {10.1038/ejhg.2015.42}, author = {Bosch, Dani{\"e}lle G M and Boonstra, F Nienke and Kinoshita, Taroh and Jhangiani, Shalini and de Ligt, Joep and Cremers, Frans P M and Lupski, James R and Murakami, Yoshiko and de Vries, Bert B A} } @article {160, title = {Cognitive phenotypes and genomic copy number variations.}, journal = {JAMA}, volume = {313}, year = {2015}, month = {2015 May 26}, pages = {2029-30}, keywords = {DNA Copy Number Variations, Female, Heterozygote, Humans, Intellectual Disability, Male, Mental Disorders}, issn = {1538-3598}, doi = {10.1001/jama.2015.4846}, author = {Lupski, James R} } @article {146, title = {GeneMatcher aids in the identification of a new malformation syndrome with intellectual disability, unique facial dysmorphisms, and skeletal and connective tissue abnormalities caused by de novo variants in HNRNPK.}, journal = {Hum Mutat}, volume = {36}, year = {2015}, month = {2015 Oct}, pages = {1009-1014}, abstract = {

We report a new syndrome due to loss-of-function variants in the heterogeneous nuclear ribonucleoprotein K gene (HNRNPK). We describe two probands: one with a de novo frameshift (NM_002140.3: c.953+1dup), and the other with a de novo splice donor site variant (NM_002140.3: c.257G>A). Both probands have intellectual disability, a shared unique craniofacial phenotype, and connective tissue and skeletal abnormalities. The identification of this syndrome was made possible by a new online tool, GeneMatcher, which facilitates connections between clinicians and researchers based on shared interest in candidate genes. This report demonstrates that new Web-based approaches can be effective in helping investigators solve exome sequencing projects, and also highlights the newer paradigm of "reverse phenotyping," where characterization of syndromic features follows the identification of genetic variants.

}, keywords = {Abnormalities, Multiple, Adolescent, Child, Craniofacial Abnormalities, Databases, Genetic, Genetic Predisposition to Disease, Heterogeneous-Nuclear Ribonucleoprotein K, Humans, Information Dissemination, Intellectual Disability, Male, Muscular Atrophy, Phenotype, Polymorphism, Single Nucleotide, Ribonucleoproteins, Software, Web Browser}, issn = {1098-1004}, doi = {10.1002/humu.22837}, author = {Au, P Y Billie and You, Jing and Caluseriu, Oana and Schwartzentruber, Jeremy and Majewski, Jacek and Bernier, Francois P and Ferguson, Marcia and Valle, David and Parboosingh, Jillian S and Sobreira, Nara and Innes, A Micheil and Kline, Antonie D} } @article {130, title = {Mutations in SPATA5 Are Associated with Microcephaly, Intellectual Disability, Seizures, and Hearing Loss.}, journal = {Am J Hum Genet}, volume = {97}, year = {2015}, month = {2015 Sep 03}, pages = {457-64}, abstract = {

Using whole-exome sequencing, we have identified in ten families 14 individuals with microcephaly, developmental delay, intellectual disability, hypotonia, spasticity, seizures, sensorineural hearing loss, cortical visual impairment, and rare autosomal-recessive predicted pathogenic variants in spermatogenesis-associated protein 5 (SPATA5). SPATA5 encodes a ubiquitously expressed member of the ATPase associated with diverse activities (AAA) protein family and is involved in mitochondrial morphogenesis during early spermatogenesis. It might also play a role in post-translational modification during cell differentiation in neuronal development. Mutations in SPATA5 might affect brain development and function, resulting in microcephaly, developmental delay, and intellectual disability.

}, keywords = {Abnormalities, Multiple, Amino Acid Sequence, ATPases Associated with Diverse Cellular Activities, Base Sequence, Exome, Female, Gene Frequency, Genes, Recessive, Hearing Loss, Homeodomain Proteins, Humans, Intellectual Disability, Male, Microcephaly, Molecular Sequence Data, Mutation, Seizures, Sequence Alignment, Sequence Analysis, DNA}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.07.014}, author = {Tanaka, Akemi J and Cho, Megan T and Millan, Francisca and Juusola, Jane and Retterer, Kyle and Joshi, Charuta and Niyazov, Dmitriy and Garnica, Adolfo and Gratz, Edward and Deardorff, Matthew and Wilkins, Alisha and Ortiz-Gonzalez, Xilma and Mathews, Katherine and Panzer, Karin and Brilstra, Eva and van Gassen, Koen L I and Volker-Touw, Catharina M L and van Binsbergen, Ellen and Sobreira, Nara and Hamosh, Ada and McKnight, Dianalee and Monaghan, Kristin G and Chung, Wendy K} } @article {223, title = {NGLY1 mutation causes neuromotor impairment, intellectual disability, and neuropathy.}, journal = {Eur J Med Genet}, volume = {58}, year = {2015}, month = {2015 Jan}, pages = {39-43}, abstract = {

N-glycanase 1 (NGLY1) is a conserved enzyme that is responsible for the deglycosylation of misfolded N-glycosylated proteins in the cytoplasm prior to their proteasome-mediated degradation. Disruption of this degradation process has been associated with various neurologic diseases including amyotrophic lateral sclerosis and Parkinson{\textquoteright}s disease. Here, we describe two siblings with neuromotor impairment, apparent intellectual disability, corneal opacities, and neuropathy who were found to possess a novel homozygous frame-shift mutation due to a 4 base pair deletion in NGLY1 (c.1533_1536delTCAA, p.Asn511LysfsX51). We hypothesize that this mutation likely limits the capability of neuronal cells to respond to stress due to accumulation of misfolded proteins, thereby impairing their survival and resulting in progressive loss of neurological function.

}, keywords = {Abnormalities, Multiple, Adolescent, Child, Corneal Opacity, Developmental Disabilities, Female, Frameshift Mutation, Genotype, Humans, Intellectual Disability, Male, Movement Disorders, Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase, Peripheral Nervous System Diseases}, issn = {1878-0849}, doi = {10.1016/j.ejmg.2014.08.008}, author = {{\c C}a{\u g}layan, Ahmet Okay and Comu, Sinan and Baranoski, Jacob F and Parman, Yesim and Kaymak{\c c}alan, Hande and Akg{\"u}m{\"u}{\c s}, G{\"o}zde Tu{\u g}ce and Caglar, Caner and D{\"o}len, Duygu and Erson-Omay, Emine Zeynep and Harmanci, Akdes Serin and Mishra-Gorur, Ketu and Freeze, Hudson H and Yasuno, Katsuhito and Bilguvar, Kaya and G{\"u}nel, Murat} } @article {205, title = {Biallelic truncating mutations in FMN2, encoding the actin-regulatory protein Formin 2, cause nonsyndromic autosomal-recessive intellectual disability.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Dec 04}, pages = {721-8}, abstract = {

Dendritic spines represent the major site of neuronal activity in the brain; they serve as the receiving point for neurotransmitters and undergo rapid activity-dependent morphological changes that correlate with learning and memory. Using a combination of homozygosity mapping and next-generation sequencing in two consanguineous families affected by nonsyndromic autosomal-recessive intellectual disability, we identified truncating mutations in formin 2 (FMN2), encoding a protein that belongs to the formin family of actin cytoskeleton nucleation factors and is highly expressed in the maturing brain. We found that FMN2 localizes to punctae along dendrites and that germline inactivation of mouse Fmn2 resulted in animals with decreased spine density; such mice were previously demonstrated to have a conditioned fear-learning defect. Furthermore, patient neural cells derived from induced pluripotent stem cells showed correlated decreased synaptic density. Thus, FMN2 mutations link intellectual disability either directly or indirectly to the regulation of actin-mediated synaptic spine density.

}, keywords = {Adolescent, Adult, Base Sequence, Chromosome Disorders, Cohort Studies, Consanguinity, Egypt, Exome, Female, Genes, Recessive, Genetic Linkage, High-Throughput Nucleotide Sequencing, Homozygote, Humans, Intellectual Disability, Male, Microfilament Proteins, Molecular Sequence Data, Nuclear Proteins, Pakistan, Pedigree, Sequence Analysis, DNA, Sequence Deletion}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.10.016}, author = {Law, Rosalind and Dixon-Salazar, Tracy and Jerber, Julie and Cai, Na and Abbasi, Ansar A and Zaki, Maha S and Mittal, Kirti and Gabriel, Stacey B and Rafiq, Muhammad Arshad and Khan, Valeed and Nguyen, Maria and Ali, Ghazanfar and Copeland, Brett and Scott, Eric and Vasli, Nasim and Mikhailov, Anna and Khan, Muhammad Nasim and Andrade, Danielle M and Ayaz, Muhammad and Ansar, Muhammad and Ayub, Muhammad and Vincent, John B and Gleeson, Joseph G} } @article {248, title = {De novo truncating mutations in AHDC1 in individuals with syndromic expressive language delay, hypotonia, and sleep apnea.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 May 01}, pages = {784-9}, abstract = {

Clinical whole-exome sequencing (WES) for identification of mutations leading to Mendelian disease has been offered to the medical community since 2011. Clinically undiagnosed neurological disorders are the most frequent basis for test referral, and currently, approximately 25\% of such cases are diagnosed at the molecular level. To date, there are approximately 4,000 "known" disease-associated loci, and many are associated with striking dysmorphic features, making genotype-phenotype correlations relatively straightforward. A significant fraction of cases, however, lack characteristic dysmorphism or clinical pathognomonic traits and are dependent upon molecular tests for definitive diagnoses. Further, many molecular diagnoses are guided by recent gene-disease association discoveries. Hence, there is a critical interplay between clinical testing and research leading to gene-disease association discovery. Here, we describe four probands, all of whom presented with hypotonia, intellectual disability, global developmental delay, and mildly dysmorphic facial features. Three of the four also had sleep apnea. Each was a simplex case without a remarkable family history. Using WES, we identified AHDC1 de novo truncating mutations that most likely cause this genetic syndrome.

}, keywords = {Child, Child, Preschool, DNA-Binding Proteins, Exome, Female, Humans, Infant, Intellectual Disability, Language Development Disorders, Male, Muscle Hypotonia, Mutation, Sleep Apnea Syndromes, Syndrome}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.04.006}, author = {Xia, Fan and Bainbridge, Matthew N and Tan, Tiong Yang and Wangler, Michael F and Scheuerle, Angela E and Zackai, Elaine H and Harr, Margaret H and Sutton, V Reid and Nalam, Roopa L and Zhu, Wenmiao and Nash, Margot and Ryan, Monique M and Yaplito-Lee, Joy and Hunter, Jill V and Deardorff, Matthew A and Penney, Samantha J and Beaudet, Arthur L and Plon, Sharon E and Boerwinkle, Eric A and Lupski, James R and Eng, Christine M and Muzny, Donna M and Yang, Yaping and Gibbs, Richard A} } @article {209, title = {Dosage changes of a segment at 17p13.1 lead to intellectual disability and microcephaly as a result of complex genetic interaction of multiple genes.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Nov 06}, pages = {565-78}, abstract = {

The 17p13.1 microdeletion syndrome is a recently described genomic disorder with a core clinical phenotype of intellectual disability, poor to absent speech, dysmorphic features, and a constellation of more variable clinical features, most prominently microcephaly. We identified five subjects with copy-number variants (CNVs) on 17p13.1 for whom we performed detailed clinical and molecular studies. Breakpoint mapping and retrospective analysis of published cases refined the smallest region of overlap (SRO) for microcephaly to a genomic interval containing nine genes. Dissection of this phenotype in zebrafish embryos revealed a complex genetic architecture: dosage perturbation of four genes (ASGR1, ACADVL, DVL2, and GABARAP) impeded neurodevelopment and decreased dosage of the same loci caused a reduced mitotic index in~vitro. Moreover, epistatic analyses in~vivo showed that dosage perturbations of discrete gene pairings induce microcephaly. Taken together, these studies support a model in which concomitant dosage perturbation of multiple genes within the CNV drive the microcephaly and possibly other neurodevelopmental phenotypes associated with rearrangements in the 17p13.1 SRO.

}, keywords = {Abnormalities, Multiple, Acyl-CoA Dehydrogenase, Long-Chain, Adaptor Proteins, Signal Transducing, Animals, Asialoglycoprotein Receptor, Base Sequence, Cell Line, Chromosome Breakpoints, Chromosome Deletion, Chromosomes, Human, Pair 17, Dishevelled Proteins, Flow Cytometry, Gene Dosage, Humans, Immunohistochemistry, Intellectual Disability, Microcephaly, Microtubule-Associated Proteins, Molecular Sequence Data, Phosphoproteins, Retrospective Studies, Sequence Analysis, DNA, Smith-Magenis Syndrome, Syndrome, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.10.006}, author = {Carvalho, Claudia M B and Vasanth, Shivakumar and Shinawi, Marwan and Russell, Chad and Ramocki, Melissa B and Brown, Chester W and Graakjaer, Jesper and Skytte, Anne-Bine and Vianna-Morgante, Angela M and Krepischi, Ana C V and Patel, Gayle S and Immken, LaDonna and Aleck, Kyrieckos and Lim, Cynthia and Cheung, Sau Wai and Rosenberg, Carla and Katsanis, Nicholas and Lupski, James R} } @article {227, title = {Exome sequencing identifies a recurrent de novo ZSWIM6 mutation associated with acromelic frontonasal dysostosis.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Aug 07}, pages = {235-40}, abstract = {

Acromelic frontonasal dysostosis (AFND) is a rare disorder characterized by distinct craniofacial, brain, and limb malformations, including frontonasal dysplasia, interhemispheric lipoma, agenesis of the corpus callosum, tibial hemimelia, preaxial polydactyly of the feet, and intellectual disability. Exome sequencing of one trio and two unrelated probands revealed the same heterozygous variant (c.3487C>T [p. Arg1163Trp]) in a highly conserved protein domain of ZSWIM6; this variant has not been seen in the 1000 Genomes data, dbSNP, or the Exome Sequencing Project. Sanger validation of the three trios confirmed that the variant was de novo and was also present in a fourth isolated proband. In situ hybridization of early zebrafish embryos at 24 hr postfertilization (hpf) demonstrated telencephalic expression of zswim6 and onset of midbrain, hindbrain, and retinal expression at 48 hpf. Immunohistochemistry of later-stage mouse embryos demonstrated tissue-specific expression in the derivatives of all three germ layers. qRT-PCR expression analysis of osteoblast and fibroblast cell lines available from two probands was suggestive of Hedgehog pathway activation, indicating that the ZSWIM6 mutation associated with AFND may lead to the craniofacial, brain and limb malformations through the disruption of Hedgehog signaling.

}, keywords = {Abnormalities, Multiple, Amino Acid Sequence, Animals, Base Sequence, Craniofacial Abnormalities, DNA Mutational Analysis, DNA-Binding Proteins, Exome, Face, Hedgehog Proteins, Humans, Intellectual Disability, Limb Deformities, Congenital, Mandibulofacial Dysostosis, Mice, Molecular Sequence Data, Mutation, Protein Structure, Tertiary, Zebrafish, Zinc Fingers}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.07.008}, author = {Smith, Joshua D and Hing, Anne V and Clarke, Christine M and Johnson, Nathan M and Perez, Francisco A and Park, Sarah S and Horst, Jeremy A and Mecham, Brig and Maves, Lisa and Nickerson, Deborah A and Cunningham, Michael L} } @article {258, title = {Expanding the phenotypic spectrum of ARID1B-mediated disorders and identification of altered cell-cycle dynamics due to ARID1B haploinsufficiency.}, journal = {Orphanet J Rare Dis}, volume = {9}, year = {2014}, month = {2014 Mar 27}, pages = {43}, abstract = {

BACKGROUND: Mutations in genes encoding components of the Brahma-associated factor (BAF) chromatin remodeling complex have recently been shown to contribute to multiple syndromes characterised by developmental delay and intellectual disability. ARID1B mutations have been identified as the predominant cause of Coffin-Siris syndrome and have also been shown to be a frequent cause of nonsyndromic intellectual disability. Here, we investigate the molecular basis of a patient with an overlapping but distinctive phenotype of intellectual disability, plantar fat pads and facial dysmorphism.

METHODS/RESULTS: High density microarray analysis of the patient demonstrated a heterozygous deletion at 6q25.3, which resulted in the loss of four genes including AT Rich Interactive Domain 1B (ARID1B). Subsequent quantitative real-time PCR analysis revealed ARID1B haploinsufficiency in the patient. Analysis of both patient-derived and ARID1B knockdown fibroblasts after serum starvation demonstrated delayed cell cycle re-entry associated with reduced cell number in the S1 phase. Based on the patient{\textquoteright}s distinctive phenotype, we ascertained four additional patients and identified heterozygous de novo ARID1B frameshift or nonsense mutations in all of them.

CONCLUSIONS: This study broadens the spectrum of ARID1B associated phenotypes by describing a distinctive phenotype including plantar fat pads but lacking the hypertrichosis or fifth nail hypoplasia associated with Coffin-Siris syndrome. We present the first direct evidence in patient-derived cells that alterations in cell cycle contribute to the underlying pathogenesis of syndromes associated with ARID1B haploinsufficiency.

}, keywords = {Abnormalities, Multiple, Cell Cycle, Chromatin Assembly and Disassembly, DNA-Binding Proteins, Face, Female, Hand Deformities, Congenital, Haploinsufficiency, Humans, Intellectual Disability, Male, Micrognathism, Neck, Transcription Factors}, issn = {1750-1172}, doi = {10.1186/1750-1172-9-43}, author = {Sim, Joe C H and White, Susan M and Fitzpatrick, Elizabeth and Wilson, Gabrielle R and Gillies, Greta and Pope, Kate and Mountford, Hayley S and Torring, Pernille M and McKee, Shane and Vulto-van Silfhout, Anneke T and Jhangiani, Shalini N and Muzny, Donna M and Leventer, Richard J and Delatycki, Martin B and Amor, David J and Lockhart, Paul J} } @article {281, title = {The genetic basis of DOORS syndrome: an exome-sequencing study.}, journal = {Lancet Neurol}, volume = {13}, year = {2014}, month = {2014 Jan}, pages = {44-58}, abstract = {

BACKGROUND: Deafness, onychodystrophy, osteodystrophy, mental retardation, and seizures (DOORS) syndrome is a rare autosomal recessive disorder of unknown cause. We aimed to identify the genetic basis of this syndrome by sequencing most coding exons in affected individuals.

METHODS: Through a search of available case studies and communication with collaborators, we identified families that included at least one individual with at least three of the five main features of the DOORS syndrome: deafness, onychodystrophy, osteodystrophy, intellectual disability, and seizures. Participants were recruited from 26 centres in 17 countries. Families described in this study were enrolled between Dec 1, 2010, and March 1, 2013. Collaborating physicians enrolling participants obtained clinical information and DNA samples from the affected child and both parents if possible. We did whole-exome sequencing in affected individuals as they were enrolled, until we identified a candidate gene, and Sanger sequencing to confirm mutations. We did expression studies in human fibroblasts from one individual by real-time PCR and western blot analysis, and in mouse tissues by immunohistochemistry and real-time PCR.

FINDINGS: 26 families were included in the study. We did exome sequencing in the first 17 enrolled families; we screened for TBC1D24 by Sanger sequencing in subsequent families. We identified TBC1D24 mutations in 11 individuals from nine families (by exome sequencing in seven families, and Sanger sequencing in two families). 18 families had individuals with all five main features of DOORS syndrome, and TBC1D24 mutations were identified in half of these families. The seizure types in individuals with TBC1D24 mutations included generalised tonic-clonic, complex partial, focal clonic, and infantile spasms. Of the 18 individuals with DOORS syndrome from 17 families without TBC1D24 mutations, eight did not have seizures and three did not have deafness. In expression studies, some mutations abrogated TBC1D24 mRNA stability. We also detected Tbc1d24 expression in mouse phalangeal chondrocytes and calvaria, which suggests a role of TBC1D24 in skeletogenesis.

INTERPRETATION: Our findings suggest that mutations in TBC1D24 seem to be an important cause of DOORS syndrome and can cause diverse phenotypes. Thus, individuals with DOORS syndrome without deafness and seizures but with the other features should still be screened for TBC1D24 mutations. More information is needed to understand the cellular roles of TBC1D24 and identify the genes responsible for DOORS phenotypes in individuals who do not have a mutation in TBC1D24.

FUNDING: US National Institutes of Health, the CIHR (Canada), the NIHR (UK), the Wellcome Trust, the Henry Smith Charity, and Action Medical Research.

}, keywords = {Adolescent, Carrier Proteins, Child, Child, Preschool, Craniofacial Abnormalities, Exome, Female, Hand Deformities, Congenital, Hearing Loss, Sensorineural, Humans, Infant, Intellectual Disability, Internationality, Male, Nails, Malformed, Phenotype, Sequence Analysis, DNA, Young Adult}, issn = {1474-4465}, doi = {10.1016/S1474-4422(13)70265-5}, author = {Campeau, Philippe M and Kasperaviciute, Dalia and Lu, James T and Burrage, Lindsay C and Kim, Choel and Hori, Mutsuki and Powell, Berkley R and Stewart, Fiona and F{\'e}lix, T{\^e}mis Maria and van den Ende, Jenneke and Wisniewska, Marzena and Kayserili, H{\"u}lya and Rump, Patrick and Nampoothiri, Sheela and Aftimos, Salim and Mey, Antje and Nair, Lal D V and Begleiter, Michael L and De Bie, Isabelle and Meenakshi, Girish and Murray, Mitzi L and Repetto, Gabriela M and Golabi, Mahin and Blair, Edward and Male, Alison and Giuliano, Fabienne and Kariminejad, Ariana and Newman, William G and Bhaskar, Sanjeev S and Dickerson, Jonathan E and Kerr, Bronwyn and Banka, Siddharth and Giltay, Jacques C and Wieczorek, Dagmar and Tostevin, Anna and Wiszniewska, Joanna and Cheung, Sau Wai and Hennekam, Raoul C and Gibbs, Richard A and Lee, Brendan H and Sisodiya, Sanjay M} } @article {243, title = {Monoallelic and biallelic mutations in MAB21L2 cause a spectrum of major eye malformations.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 Jun 05}, pages = {915-23}, abstract = {

We identified four different missense mutations in the single-exon gene MAB21L2 in eight individuals with bilateral eye malformations from five unrelated families via three independent exome sequencing projects. Three mutational events altered the same amino acid (Arg51), and two were identical de novo mutations (c.151C>T [p.Arg51Cys]) in unrelated children with bilateral anophthalmia, intellectual disability, and rhizomelic skeletal dysplasia. c.152G>A (p.Arg51His) segregated with autosomal-dominant bilateral colobomatous microphthalmia in a large multiplex family. The fourth heterozygous mutation (c.145G>A [p.Glu49Lys]) affected an amino acid within two residues of Arg51 in an adult male with bilateral colobomata. In a fifth family, a homozygous mutation (c.740G>A [p.Arg247Gln]) altering a different region of the protein was identified in two male siblings with bilateral retinal colobomata. In mouse embryos, Mab21l2 showed strong expression in the developing eye, pharyngeal arches, and limb bud. As predicted by structural homology, wild-type MAB21L2 bound single-stranded RNA, whereas this activity was lost in all altered forms of the protein. MAB21L2 had no detectable nucleotidyltransferase activity in~vitro, and its function remains unknown. Induced expression of wild-type MAB21L2 in human embryonic kidney 293 cells increased phospho-ERK (pERK1/2) signaling. Compared to the wild-type and p.Arg247Gln proteins, the proteins with the Glu49 and Arg51 variants had increased stability. Abnormal persistence of pERK1/2 signaling in MAB21L2-expressing cells during development is a plausible pathogenic mechanism for the heterozygous mutations. The phenotype associated with the homozygous mutation might be a consequence of complete loss of MAB21L2 RNA binding, although the cellular function of this interaction remains unknown.

}, keywords = {Adult, Alleles, Animals, Anophthalmos, Brain Diseases, Metabolic, Inborn, Coloboma, Corneal Opacity, Exome, Eye Proteins, Female, Gene Expression, HEK293 Cells, Heterozygote, Homozygote, Humans, Intellectual Disability, Intracellular Signaling Peptides and Proteins, Male, Mice, Microcephaly, Microphthalmos, Mutation, Missense, Pedigree, Phenotype, Protein Conformation, Signal Transduction}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.05.005}, author = {Rainger, Joe and Pehlivan, Davut and Johansson, Stefan and Bengani, Hemant and Sanchez-Pulido, Luis and Williamson, Kathleen A and Ture, Mehmet and Barker, Heather and Rosendahl, Karen and Spranger, J{\"u}rgen and Horn, Denise and Meynert, Alison and Floyd, James A B and Prescott, Trine and Anderson, Carl A and Rainger, Jacqueline K and Karaca, Ender and Gonzaga-Jauregui, Claudia and Jhangiani, Shalini and Muzny, Donna M and Seawright, Anne and Soares, Dinesh C and Kharbanda, Mira and Murday, Victoria and Finch, Andrew and Gibbs, Richard A and van Heyningen, Veronica and Taylor, Martin S and Yakut, Tahsin and Knappskog, Per M and Hurles, Matthew E and Ponting, Chris P and Lupski, James R and Houge, Gunnar and FitzPatrick, David R} } @article {271, title = {NR2F1 mutations cause optic atrophy with intellectual disability.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 Feb 06}, pages = {303-9}, abstract = {

Optic nerve atrophy and hypoplasia can be primary disorders or can result from trans-synaptic degeneration arising from cerebral visual impairment (CVI). Here we report six individuals with CVI and/or optic nerve abnormalities, born after an uneventful pregnancy and delivery, who have either de novo heterozygous missense mutations in NR2F1, also known as COUP-TFI, or deletions encompassing NR2F1. All affected individuals show mild to moderate intellectual impairment. NR2F1 encodes a nuclear receptor protein that regulates transcription. A reporter assay showed that missense mutations in the zinc-finger DNA-binding domain and the putative ligand-binding domain decrease NR2F1 transcriptional activity. These findings indicate that NR2F1 plays an important role in the neurodevelopment of the visual system and that its disruption can lead to optic atrophy with intellectual disability.

}, keywords = {Adolescent, Adult, Amino Acid Sequence, Child, Child, Preschool, COUP Transcription Factor I, DNA-Binding Proteins, Female, Genotype, Humans, Intellectual Disability, Male, Molecular Sequence Data, Mutation, Missense, Optic Atrophy, Phenotype, Young Adult, Zinc Fingers}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.01.002}, author = {Bosch, Dani{\"e}lle G M and Boonstra, F Nienke and Gonzaga-Jauregui, Claudia and Xu, Mafei and de Ligt, Joep and Jhangiani, Shalini and Wiszniewski, Wojciech and Muzny, Donna M and Yntema, Helger G and Pfundt, Rolph and Vissers, Lisenka E L M and Spruijt, Liesbeth and Blokland, Ellen A W and Chen, Chun-An and Lewis, Richard A and Tsai, Sophia Y and Gibbs, Richard A and Tsai, Ming-Jer and Lupski, James R and Zoghbi, Huda Y and Cremers, Frans P M and de Vries, Bert B A and Schaaf, Christian P} } @article {272, title = {Whole-exome sequencing links TMCO1 defect syndrome with cerebro-facio-thoracic dysplasia.}, journal = {Eur J Hum Genet}, volume = {22}, year = {2014}, month = {2014 Sep}, pages = {1145-8}, abstract = {

Whole-exome sequencing (WES) is a type of disruptive technology that has tremendous influence on human and clinical genetics research. An efficient and cost-effective method, WES is now widely used as a diagnostic tool for identifying the molecular basis of genetic syndromes that are often challenging to diagnose. Here we report a patient with a clinical diagnosis of cerebro-facio-thoracic dysplasia (CFTD; MIM$\#$213980) in whom we identified a homozygous splice-site mutation in the transmembrane and coiled-coil domains 1 (TMCO1) gene using WES. TMCO1 mutations cause craniofacial dysmorphism, skeletal anomalies characterized by multiple malformations of the vertebrae and ribs, and intellectual disability (MIM$\#$614132). A retrospective review revealed that clinical manifestations of both syndromes are very similar and overlap remarkably. We propose that mutations of TMCO1 are not only responsible for craniofacial dysmorphism, skeletal anomalies and mental retardation syndrome but also for CFTD.

}, keywords = {Abnormalities, Multiple, Exome, Humans, Infant, Intellectual Disability, Male, Membrane Proteins, Mutation, Protein Isoforms}, issn = {1476-5438}, doi = {10.1038/ejhg.2013.291}, author = {Pehlivan, Davut and Karaca, Ender and Aydin, Hatip and Beck, Christine R and Gambin, Tomasz and Muzny, Donna M and Bilge Geckinli, B and Karaman, Ali and Jhangiani, Shalini N and Gibbs, Richard A and Lupski, James R} }