@article {963, title = {Absent B cells, agammaglobulinemia, and hypertrophic cardiomyopathy in folliculin-interacting protein 1 deficiency.}, journal = {Blood}, volume = {137}, year = {2021}, month = {2021 01 28}, pages = {493-499}, abstract = {

Agammaglobulinemia is the most profound primary antibody deficiency that can occur due to an early termination of B-cell development. We here investigated 3 novel patients, including the first known adult, from unrelated families with agammaglobulinemia, recurrent infections, and hypertrophic cardiomyopathy (HCM). Two of them also presented with intermittent or severe chronic neutropenia. We identified homozygous or compound-heterozygous variants in the gene for folliculin interacting protein 1 (FNIP1), leading to loss of the FNIP1 protein. B-cell metabolism, including mitochondrial numbers and activity and phosphatidylinositol 3-kinase/AKT pathway, was impaired. These defects recapitulated the Fnip1-/- animal model. Moreover, we identified either uniparental disomy or copy-number variants (CNVs) in 2 patients, expanding the variant spectrum of this novel inborn error of immunity. The results indicate that FNIP1 deficiency can be caused by complex genetic mechanisms and support the clinical utility of exome sequencing and CNV analysis in patients with broad phenotypes, including agammaglobulinemia and HCM. FNIP1 deficiency is a novel inborn error of immunity characterized by early and severe B-cell development defect, agammaglobulinemia, variable neutropenia, and HCM. Our findings elucidate a functional and relevant role of FNIP1 in B-cell development and metabolism and potentially neutrophil activity.

}, keywords = {Adult, Agammaglobulinemia, Animals, B-Lymphocytes, Cardiomyopathy, Hypertrophic, Carrier Proteins, Child, Child, Preschool, Chromosomes, Human, Pair 5, Codon, Nonsense, Consanguinity, Crohn Disease, Developmental Disabilities, Disease Models, Animal, Disease Susceptibility, DNA Copy Number Variations, Female, Heart Defects, Congenital, Humans, Immunologic Deficiency Syndromes, Infections, Loss of Function Mutation, Lymphopenia, Male, Mice, Neutropenia, Pedigree, Uniparental Disomy, Whole Exome Sequencing}, issn = {1528-0020}, doi = {10.1182/blood.2020006441}, author = {Saettini, Francesco and Poli, Cecilia and Vengoechea, Jaime and Bonanomi, Sonia and Orellana, Julio C and Fazio, Grazia and Rodriguez, Fred H and Noguera, Loreani P and Booth, Claire and Jarur-Chamy, Valentina and Shams, Marissa and Iascone, Maria and Vukic, Maja and Gasperini, Serena and Quadri, Manuel and Barroeta Seijas, Amairelys and Rivers, Elizabeth and Mauri, Mario and Badolato, Raffaele and Cazzaniga, Gianni and Bugarin, Cristina and Gaipa, Giuseppe and Kroes, Wilma G M and Moratto, Daniele and van Oostaijen-Ten Dam, Monique M and Baas, Frank and van der Maarel, Silv{\`e}re and Piazza, Rocco and Coban-Akdemir, Zeynep H and Lupski, James R and Yuan, Bo and Chinn, Ivan K and Daxinger, Lucia and Biondi, Andrea} } @article {1007, title = {De novo TRIM8 variants impair its protein localization to nuclear bodies and cause developmental delay, epilepsy, and focal segmental glomerulosclerosis.}, journal = {Am J Hum Genet}, volume = {108}, year = {2021}, month = {2021 02 04}, pages = {357-367}, abstract = {

Focal segmental glomerulosclerosis (FSGS) is the main pathology underlying steroid-resistant nephrotic syndrome (SRNS) and a leading cause of chronic kidney disease. Monogenic forms of pediatric SRNS are predominantly caused by recessive mutations, while the contribution of de novo variants (DNVs) to this trait is poorly understood. Using exome sequencing (ES) in a proband with FSGS/SRNS, developmental delay, and epilepsy, we discovered a nonsense DNV in TRIM8, which encodes the E3 ubiquitin ligase tripartite motif containing 8. To establish whether TRIM8 variants represent a cause of FSGS, we aggregated exome/genome-sequencing data for 2,501 pediatric FSGS/SRNS-affected individuals and 48,556 control subjects, detecting eight heterozygous TRIM8 truncating variants in affected subjects but none in control subjects (p = 3.28~{\texttimes} 10). In all six cases with available parental DNA, we demonstrated de novo inheritance (p~=~2.21~{\texttimes} 10). Reverse phenotyping revealed neurodevelopmental disease in all eight families. We next analyzed ES from 9,067 individuals with epilepsy, yielding three additional families with truncating TRIM8 variants. Clinical review revealed FSGS in all. All TRIM8 variants cause protein truncation clustering within the last exon between residues 390 and 487 of the 551 amino acid protein, indicating a correlation between this syndrome and loss of the TRIM8 C-terminal region. Wild-type TRIM8 overexpressed in immortalized human podocytes and neuronal cells localized to nuclear bodies, while constructs harboring patient-specific variants mislocalized diffusely to the nucleoplasm. Co-localization studies demonstrated that Gemini and Cajal bodies frequently abut a TRIM8 nuclear body. Truncating TRIM8 DNVs cause a neuro-renal syndrome via aberrant TRIM8 localization, implicating nuclear bodies in FSGS and developmental brain disease.

}, keywords = {Adult, Animals, Carrier Proteins, Cell Line, Child, Child, Preschool, Codon, Nonsense, Developmental Disabilities, Epilepsy, Female, Glomerulosclerosis, Focal Segmental, Humans, Intranuclear Space, Kidney, Male, Mice, Mutation, Nephrotic Syndrome, Nerve Tissue Proteins, Phenotype, Podocytes, Whole Exome Sequencing}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2021.01.008}, author = {Weng, Patricia L and Majmundar, Amar J and Khan, Kamal and Lim, Tze Y and Shril, Shirlee and Jin, Gina and Musgrove, John and Wang, Minxian and Ahram, Dina F and Aggarwal, Vimla S and Bier, Louise E and Heinzen, Erin L and Onuchic-Whitford, Ana C and Mann, Nina and Buerger, Florian and Schneider, Ronen and Deutsch, Konstantin and Kitzler, Thomas M and Kl{\"a}mbt, Verena and Kolb, Amy and Mao, Youying and Moufawad El Achkar, Christelle and Mitrotti, Adele and Martino, Jeremiah and Beck, Bodo B and Altm{\"u}ller, Janine and Benz, Marcus R and Yano, Shoji and Mikati, Mohamad A and Gunduz, Talha and Cope, Heidi and Shashi, Vandana and Trachtman, Howard and Bodria, Monica and Caridi, Gianluca and Pisani, Isabella and Fiaccadori, Enrico and AbuMaziad, Asmaa S and Martinez-Agosto, Julian A and Yadin, Ora and Zuckerman, Jonathan and Kim, Arang and John-Kroegel, Ulrike and Tyndall, Amanda V and Parboosingh, Jillian S and Innes, A Micheil and Bierzynska, Agnieszka and Koziell, Ania B and Muorah, Mordi and Saleem, Moin A and Hoefele, Julia and Riedhammer, Korbinian M and Gharavi, Ali G and Jobanputra, Vaidehi and Pierce-Hoffman, Emma and Seaby, Eleanor G and O{\textquoteright}Donnell-Luria, Anne and Rehm, Heidi L and Mane, Shrikant and D{\textquoteright}Agati, Vivette D and Pollak, Martin R and Ghiggeri, Gian Marco and Lifton, Richard P and Goldstein, David B and Davis, Erica E and Hildebrandt, Friedhelm and Sanna-Cherchi, Simone} } @article {1001, title = {Loss of function mutations in GEMIN5 cause a neurodevelopmental disorder.}, journal = {Nat Commun}, volume = {12}, year = {2021}, month = {2021 05 07}, pages = {2558}, abstract = {

GEMIN5, an RNA-binding protein is essential for assembly of the survival motor neuron (SMN) protein complex and facilitates the formation of small nuclear ribonucleoproteins (snRNPs), the building blocks of spliceosomes. Here, we have identified 30 affected individuals from 22 unrelated families presenting with developmental delay, hypotonia, and cerebellar ataxia harboring biallelic variants in the GEMIN5 gene. Mutations in GEMIN5 perturb the subcellular distribution, stability, and expression of GEMIN5 protein and its interacting partners in patient iPSC-derived neurons, suggesting a potential loss-of-function mechanism. GEMIN5 mutations result in disruption of snRNP complex assembly formation in patient iPSC neurons. Furthermore, knock down of rigor mortis, the fly homolog of human GEMIN5, leads to developmental defects, motor dysfunction, and a reduced lifespan. Interestingly, we observed that GEMIN5 variants disrupt a distinct set of transcripts and pathways as compared to SMA patient neurons, suggesting different molecular pathomechanisms. These findings collectively provide evidence that pathogenic variants in GEMIN5 perturb physiological functions and result in a neurodevelopmental delay and ataxia syndrome.

}, keywords = {Alleles, Amino Acid Sequence, Animals, Child, Preschool, Developmental Disabilities, Drosophila, Female, Gene Expression Regulation, Developmental, Gene Knockdown Techniques, Gene Ontology, HEK293 Cells, Humans, Induced Pluripotent Stem Cells, Loss of Function Mutation, Male, Muscle Hypotonia, Myoclonic Cerebellar Dyssynergia, Neurodevelopmental Disorders, Neurons, Pedigree, Polymorphism, Single Nucleotide, Ribonucleoproteins, Small Nuclear, Rigor Mortis, RNA-Seq, SMN Complex Proteins}, issn = {2041-1723}, doi = {10.1038/s41467-021-22627-w}, author = {Kour, Sukhleen and Rajan, Deepa S and Fortuna, Tyler R and Anderson, Eric N and Ward, Caroline and Lee, Youngha and Lee, Sangmoon and Shin, Yong Beom and Chae, Jong-Hee and Choi, Murim and Siquier, Karine and Cantagrel, Vincent and Amiel, Jeanne and Stolerman, Elliot S and Barnett, Sarah S and Cousin, Margot A and Castro, Diana and McDonald, Kimberly and Kirmse, Brian and Nemeth, Andrea H and Rajasundaram, Dhivyaa and Innes, A Micheil and Lynch, Danielle and Frosk, Patrick and Collins, Abigail and Gibbons, Melissa and Yang, Michele and Desguerre, Isabelle and Boddaert, Nathalie and Gitiaux, Cyril and Rydning, Siri Lynne and Selmer, Kaja K and Urreizti, Roser and Garcia-Oguiza, Alberto and Osorio, Andr{\'e}s Nascimento and Verdura, Edgard and Pujol, Aurora and McCurry, Hannah R and Landers, John E and Agnihotri, Sameer and Andriescu, E Corina and Moody, Shade B and Phornphutkul, Chanika and Sacoto, Maria J Guillen and Begtrup, Amber and Houlden, Henry and Kirschner, Janbernd and Schorling, David and Rudnik-Sch{\"o}neborn, Sabine and Strom, Tim M and Leiz, Steffen and Juliette, Kali and Richardson, Randal and Yang, Ying and Zhang, Yuehua and Wang, Minghui and Wang, Jia and Wang, Xiaodong and Platzer, Konrad and Donkervoort, Sandra and B{\"o}nnemann, Carsten G and Wagner, Matias and Issa, Mahmoud Y and Elbendary, Hasnaa M and Stanley, Valentina and Maroofian, Reza and Gleeson, Joseph G and Zaki, MAH S and Senderek, Jan and Pandey, Udai Bhan} } @article {941, title = {MED27 Variants Cause Developmental Delay, Dystonia, and Cerebellar Hypoplasia.}, journal = {Ann Neurol}, volume = {89}, year = {2021}, month = {2021 04}, pages = {828-833}, abstract = {

The Mediator multiprotein complex functions as a regulator of RNA polymerase II-catalyzed gene transcription. In this study, exome sequencing detected biallelic putative disease-causing variants in MED27, encoding Mediator complex subunit 27, in 16 patients from 11 families with a novel neurodevelopmental syndrome. Patient phenotypes are highly homogeneous, including global developmental delay, intellectual disability, axial hypotonia with distal spasticity, dystonic movements, and cerebellar hypoplasia. Seizures and cataracts were noted in severely affected individuals. Identification of multiple patients with biallelic MED27 variants supports the critical role of MED27 in normal human neural development, particularly for the cerebellum. ANN NEUROL 2021;89:828-833.

}, keywords = {Adolescent, Adult, Amino Acid Sequence, Cataract, Cerebellum, Child, Child, Preschool, Developmental Disabilities, Dystonia, Epilepsy, Genetic Variation, Humans, Infant, Mediator Complex, Nervous System Malformations, Phenotype, Whole Exome Sequencing}, issn = {1531-8249}, doi = {10.1002/ana.26019}, author = {Meng, Linyan and Isohanni, Pirjo and Shao, Yunru and GrAHm, Brett H and Hickey, Scott E and Brooks, Stephanie and Suomalainen, Anu and Joset, Pascal and Steindl, Katharina and Rauch, Anita and Hackenberg, Annette and High, Frances A and Armstrong-Javors, Amy and Mencacci, Niccol{\`o} E and Gonz{\`a}lez-Latapi, Paulina and Kamel, Walaa A and Al-Hashel, Jasem Y and Bustos, Bernab{\'e} I and Hernandez, Alejandro V and Krainc, Dimitri and Lubbe, Steven J and Van Esch, Hilde and De Luca, Chiara and Ballon, Katleen and Ravelli, Claudia and Burglen, Lydie and Qebibo, Leila and Calame, Daniel G and Mitani, Tadahiro and Marafi, Dana and Pehlivan, Davut and Saadi, Nebal W and Sahin, Yavuz and Maroofian, Reza and Efthymiou, Stephanie and Houlden, Henry and Maqbool, Shazia and Rahman, Fatima and Gu, Shen and Posey, Jennifer E and Lupski, James R and Hunter, Jill V and Wangler, Michael F and Carroll, Christopher J and Yang, Yaping} } @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 {962, title = {Bi-allelic Variations of SMO in Humans Cause a Broad Spectrum of Developmental Anomalies Due to Abnormal Hedgehog Signaling.}, journal = {Am J Hum Genet}, volume = {106}, year = {2020}, month = {2020 06 04}, pages = {779-792}, abstract = {

The evolutionarily conserved hedgehog (Hh) pathway is essential for organogenesis and plays critical roles in postnatal tissue maintenance and renewal. A unique feature of the vertebrate Hh pathway is that signal transduction requires the primary cilium (PC) where major pathway components are dynamically enriched. These factors include smoothened (SMO) and patched, which constitute the core reception system for sonic hedgehog (SHH) as well as GLI transcription factors, the key mediators of the pathway. Here, we report bi-allelic loss-of-function variations in SMO in seven individuals from five independent families; these variations cause a wide phenotypic spectrum of developmental anomalies affecting the brain (hypothalamic hamartoma and microcephaly), heart (atrioventricular septal defect), skeleton (postaxial polydactyly, narrow chest, and shortening of long bones), and enteric nervous system (aganglionosis). Cells derived from affected individuals showed normal ciliogenesis but severely altered Hh-signal transduction as a result of either altered PC trafficking or abnormal activation of the pathway downstream of SMO. In addition, Hh-independent GLI2 accumulation at the PC tip in cells from the affected individuals suggests a potential function of SMO in regulating basal ciliary trafficking of GLI2 when the pathway is off. Thus, loss of SMO function results in abnormal PC dynamics of key components of the Hh signaling pathway and leads to a large continuum of malformations in humans.

}, keywords = {Alleles, Base Sequence, Child, Child, Preschool, Cilia, Developmental Disabilities, Female, Hedgehog Proteins, Humans, Infant, Male, Models, Molecular, Neoplasms, Nerve Tissue Proteins, Nuclear Proteins, Pedigree, Signal Transduction, Smoothened Receptor, Zinc Finger Protein Gli2, Zinc Finger Protein Gli3}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2020.04.010}, author = {Le, Thuy-Linh and Sribudiani, Yunia and Dong, Xiaomin and Huber, Celine and Kois, Chelsea and Baujat, Genevi{\`e}ve and Gordon, Christopher T and Mayne, Valerie and Galmiche, Louise and Serre, Val{\'e}rie and Goudin, Nicolas and Zarhrate, Mohammed and Bole-Feysot, Christine and Masson, Cecile and Nitschk{\'e}, Patrick and Verheijen, Frans W and Pais, Lynn and Pelet, Anna and Sadedin, Simon and Pugh, John A and Shur, Natasha and White, Susan M and El Chehadeh, Salima and Christodoulou, John and Cormier-Daire, Val{\'e}rie and Hofstra, R M W and Lyonnet, Stanislas and Tan, Tiong Yang and Atti{\'e}-Bitach, Tania and Kerstjens-Frederikse, Wilhelmina S and Amiel, Jeanne and Thomas, Sophie} } @article {780, title = {De novo EIF2AK1 and EIF2AK2 Variants Are Associated with Developmental Delay, Leukoencephalopathy, and Neurologic Decompensation.}, journal = {Am J Hum Genet}, volume = {106}, year = {2020}, month = {2020 04 02}, pages = {570-583}, abstract = {

EIF2AK1 and EIF2AK2 encode members of the eukaryotic translation initiation factor 2 alpha kinase (EIF2AK) family that inhibits protein synthesis in response to physiologic stress conditions. EIF2AK2 is also involved in innate immune response and the regulation of signal transduction, apoptosis, cell proliferation, and differentiation. Despite these findings, human disorders associated with deleterious variants in EIF2AK1 and EIF2AK2 have not been reported. Here, we describe the identification of nine unrelated individuals with heterozygous de novo missense variants in EIF2AK1 (1/9) or EIF2AK2 (8/9). Features seen in these nine individuals include white matter alterations (9/9), developmental delay (9/9), impaired language (9/9), cognitive impairment (8/9), ataxia (6/9), dysarthria in probands with verbal ability (6/9), hypotonia (7/9), hypertonia (6/9), and involuntary movements (3/9). Individuals with EIF2AK2 variants also exhibit neurological regression in the setting of febrile illness or infection. We use mammalian cell lines and proband-derived fibroblasts to further confirm the pathogenicity of variants in these genes and found reduced kinase activity. EIF2AKs phosphorylate eukaryotic translation initiation factor 2 subunit 1 (EIF2S1, also known as EIF2α), which then inhibits EIF2B activity. Deleterious variants in genes encoding EIF2B proteins cause childhood ataxia with central nervous system hypomyelination/vanishing white matter (CACH/VWM), a leukodystrophy characterized by neurologic regression in the setting of febrile illness and other stressors. Our findings indicate that EIF2AK2 missense variants cause a neurodevelopmental syndrome that may share phenotypic and pathogenic mechanisms with CACH/VWM.

}, keywords = {Adolescent, Ataxia, Child, Child, Preschool, Developmental Disabilities, eIF-2 Kinase, Female, Genetic Variation, Hereditary Central Nervous System Demyelinating Diseases, Humans, Infant, Leukoencephalopathies, Male, Nervous System Malformations, White Matter}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2020.02.016}, author = {Mao, Dongxue and Reuter, Chloe M and Ruzhnikov, Maura R Z and Beck, Anita E and Farrow, Emily G and Emrick, Lisa T and Rosenfeld, Jill A and Mackenzie, Katherine M and Robak, Laurie and Wheeler, Matthew T and Burrage, Lindsay C and Jain, Mahim and Liu, Pengfei and Calame, Daniel and K{\"u}ry, S{\'e}bastien and Sillesen, Martin and Schmitz-Abe, Klaus and Tonduti, Davide and Spaccini, Luigina and Iascone, Maria and Genetti, Casie A and Koenig, Mary K and Graf, Madeline and Tran, Alyssa and Alejandro, Mercedes and Lee, Brendan H and Thiffault, Isabelle and Agrawal, Pankaj B and Bernstein, Jonathan A and Bellen, Hugo J and Chao, Hsiao-Tuan} } @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 {769, title = {Delineation of a Human Mendelian Disorder of the DNA Demethylation Machinery: TET3 Deficiency.}, journal = {Am J Hum Genet}, volume = {106}, year = {2020}, month = {2020 02 06}, pages = {234-245}, abstract = {

Germline pathogenic variants in chromatin-modifying enzymes are a common cause of pediatric developmental disorders. These enzymes catalyze reactions that regulate epigenetic inheritance via histone post-translational modifications and DNA methylation. Cytosine methylation (5-methylcytosine [5mC]) of DNA is the quintessential epigenetic mark, yet no human Mendelian disorder of DNA demethylation has yet been delineated. Here, we describe in detail a Mendelian disorder caused by the disruption of DNA demethylation. TET3 is a methylcytosine dioxygenase that initiates DNA demethylation during early zygote formation, embryogenesis, and neuronal differentiation and is intolerant to haploinsufficiency in mice and humans. We identify and characterize 11 cases of human TET3 deficiency in eight families with the common phenotypic features of intellectual disability and/or global developmental delay; hypotonia; autistic traits; movement disorders; growth abnormalities; and facial dysmorphism. Mono-allelic frameshift and nonsense variants in TET3 occur throughout the coding region. Mono-allelic and bi-allelic missense variants localize to conserved residues; all but one such variant occur within the catalytic domain, and most display hypomorphic function in an assay of catalytic activity. TET3 deficiency and other Mendelian disorders of the epigenetic machinery show substantial phenotypic overlap, including features of intellectual disability and abnormal growth, underscoring shared disease mechanisms.

}, keywords = {Adult, Amino Acid Sequence, Autistic Disorder, Child, Child, Preschool, Developmental Disabilities, Dioxygenases, DNA Demethylation, Embryonic Development, Female, Gene Expression Regulation, Developmental, Growth Disorders, Humans, Infant, Male, Middle Aged, Movement Disorders, Pedigree, Protein Conformation, Sequence Homology, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.12.007}, author = {Beck, David B and Petracovici, Ana and He, Chongsheng and Moore, Hannah W and Louie, Raymond J and Ansar, Muhammad and Douzgou, Sofia and Sithambaram, Sivagamy and Cottrell, Trudie and Santos-Cortez, Regie Lyn P and Prijoles, Eloise J and Bend, Renee and Keren, Boris and Mignot, Cyril and Nougues, Marie-Christine and {\~O}unap, Katrin and Reimand, Tiia and Pajusalu, Sander and Zahid, Muhammad and Saqib, Muhammad Arif Nadeem and Buratti, Julien and Seaby, Eleanor G and McWalter, Kirsty and Telegrafi, Aida and Baldridge, Dustin and Shinawi, Marwan and Leal, Suzanne M and Schaefer, G Bradley and Stevenson, Roger E and Banka, Siddharth and Bonasio, Roberto and Fahrner, Jill A} } @article {970, title = {A mutation affecting laminin alpha 5 polymerisation gives rise to a syndromic developmental disorder.}, journal = {Development}, volume = {147}, year = {2020}, month = {2020 06 22}, abstract = {

Laminin alpha 5 (LAMA5) is a member of a large family of proteins that trimerise and then polymerise to form a central component of all basement membranes. Consequently, the protein plays an instrumental role in shaping the normal development of the kidney, skin, neural tube, lung and limb, and many other organs and tissues. Pathogenic mutations in some laminins have been shown to cause a range of largely syndromic conditions affecting the competency of the basement membranes to which they contribute. We report the identification of a mutation in the polymerisation domain of LAMA5 in a patient with a complex syndromic disease characterised by defects in kidney, craniofacial and limb development, and by a range of other congenital defects. Using CRISPR-generated mouse models and biochemical assays, we demonstrate the pathogenicity of this variant, showing that the change results in a failure of the polymerisation of α/β/γ laminin trimers. Comparing these phenotypes with those apparent upon gene deletion in mice provides insights into the specific functional importance of laminin polymerisation during development and tissue homeostasis.

}, keywords = {Amino Acid Sequence, Animals, Animals, Newborn, Child, Preschool, Developmental Disabilities, Fetal Development, Fetus, Humans, Hydronephrosis, Infant, Newborn, Kidney, Laminin, Lung, Male, Mice, Mutation, Polymerization, Protein Domains, Syndrome}, issn = {1477-9129}, doi = {10.1242/dev.189183}, author = {Jones, Lynelle K and Lam, Rachel and McKee, Karen K and Aleksandrova, Maya and Dowling, John and Alexander, Stephen I and Mallawaarachchi, Amali and Cottle, Denny L and Short, Kieran M and Pais, Lynn and Miner, Jeffery H and Mallett, Andrew J and Simons, Cas and McCarthy, Hugh and Yurchenco, Peter D and Smyth, Ian M} } @article {928, title = {Novel congenital disorder of O-linked glycosylation caused by GALNT2 loss of function.}, journal = {Brain}, volume = {143}, year = {2020}, month = {2020 04 01}, pages = {1114-1126}, abstract = {

Congenital disorders of glycosylation are a growing group of rare genetic disorders caused by deficient protein and lipid glycosylation. Here, we report the clinical, biochemical, and molecular features of seven patients from four families with GALNT2-congenital disorder of glycosylation (GALNT2-CDG), an O-linked glycosylation disorder. GALNT2 encodes the Golgi-localized polypeptide N-acetyl-d-galactosamine-transferase 2 isoenzyme. GALNT2 is widely expressed in most cell types and directs initiation of mucin-type protein O-glycosylation. All patients showed loss of O-glycosylation of apolipoprotein C-III, a non-redundant substrate for GALNT2. Patients with GALNT2-CDG generally exhibit a syndrome characterized by global developmental delay, intellectual disability with language deficit, autistic features, behavioural abnormalities, epilepsy, chronic insomnia, white matter changes on brain MRI, dysmorphic features, decreased stature, and decreased high density lipoprotein cholesterol levels. Rodent (mouse and rat) models of GALNT2-CDG recapitulated much of the human phenotype, including poor growth and neurodevelopmental abnormalities. In behavioural studies, GALNT2-CDG mice demonstrated cerebellar motor deficits, decreased sociability, and impaired sensory integration and processing. The multisystem nature of phenotypes in patients and rodent models of GALNT2-CDG suggest that there are multiple non-redundant protein substrates of GALNT2 in various tissues, including brain, which are critical to normal growth and development.

}, keywords = {Adolescent, Animals, Apolipoprotein C-III, Child, Child, Preschool, Developmental Disabilities, Female, Glycosylation, Humans, Loss of Function Mutation, Male, Mice, N-Acetylgalactosaminyltransferases, Pedigree, Rats, Young Adult}, issn = {1460-2156}, doi = {10.1093/brain/awaa063}, author = {Zilmer, Monica and Edmondson, Andrew C and Khetarpal, Sumeet A and Alesi, Viola and Zaki, MAH S and Rostasy, Kevin and Madsen, Camilla G and Lepri, Francesca R and Sinibaldi, Lorenzo and Cusmai, Raffaella and Novelli, Antonio and Issa, Mahmoud Y and Fenger, Christina D and Abou Jamra, Rami and Reutter, Heiko and Briuglia, Silvana and Agolini, Emanuele and Hansen, Lars and Pet{\"a}j{\"a}-Repo, Ulla E and Hintze, John and Raymond, Kimiyo M and Liedtke, Kristen and Stanley, Valentina and Musaev, Damir and Gleeson, Joseph G and Vitali, Cecilia and O{\textquoteright}Brien, W Timothy and Gardella, Elena and Rubboli, Guido and Rader, Daniel J and Schjoldager, Katrine T and M{\o}ller, Rikke S} } @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 {755, title = {Severe neurodevelopmental disease caused by a homozygous TLK2 variant.}, journal = {Eur J Hum Genet}, volume = {28}, year = {2020}, month = {2020 03}, pages = {383-387}, abstract = {

A distinct neurodevelopmental phenotype characterised mainly by mild motor and language delay and facial dysmorphism, caused by heterozygous de novo or dominant variants in the TLK2 gene has recently been described. All cases reported carried either truncating variants located throughout the gene, or missense changes principally located at the C-terminal end of the protein mostly resulting in haploinsufficiency of TLK2. Through whole exome sequencing, we identified a homozygous missense variant in TLK2 in a patient showing more severe symptoms than those previously described, including cerebellar vermis hypoplasia and West syndrome. Both parents are heterozygous for the variant and clinically unaffected highlighting that recessive variants in TLK2 can also be disease causing and may act through a different pathomechanism.

}, keywords = {Adult, Cerebellum, Child, Developmental Disabilities, Female, Heterozygote, Homozygote, Humans, Infant, Male, Mutation, Missense, Nervous System Malformations, Pedigree, Protein Kinases, Spasms, Infantile}, issn = {1476-5438}, doi = {10.1038/s41431-019-0519-x}, author = {Topf, Ana and Oktay, Yavuz and Balaraju, Sunitha and Yilmaz, Elmasnur and Sonmezler, Ece and Yis, Uluc and Laurie, Steven and Thompson, Rachel and Roos, Andreas and MacArthur, Daniel G and Yaramis, Ahmet and G{\"u}ng{\"o}r, Serdal and Lochm{\"u}ller, Hanns and Hiz, Semra and Horvath, Rita} } @article {966, title = {Successful treatment of intractable epilepsy with ketogenic diet therapy in twins with ALG3-CDG.}, journal = {Brain Dev}, volume = {42}, year = {2020}, month = {2020 Aug}, pages = {539-545}, abstract = {

BACKGROUND: Congenital disorders of glycosylation (CDG) is a heterogeneous group of congenital metabolic diseases with multisystem clinical involvement. ALG3-CDG is a very rare subtype with only 24 cases reported so far.

CASE: Here, we report two siblings with dysmorphic features, growth retardation, microcephaly, intractable epilepsy, and hemangioma in the frontal, occipital and lumbosacral regions.

RESULTS: We studied two siblings by whole exome sequencing. A pathogenic variant in ALG3 (NM_005787.6: c.165C~>~T; p.Gly55=) that had been previously associated with congenital glycolysis defect type 1d was identified. Their intractable seizures were controlled by ketogenic diet.

CONCLUSION: Although prominent findings of growth retardation and microcephaly seen in our patients have been extensively reported before, presence of hemangioma is a novel finding that may be used as an indication for ALG3-CDG diagnosis. Our patients are the first reported cases whose intractable seizures were controlled with ketogenic diet. This report adds ketogenic diet as an option for treatment of intractable epilepsy in ALG3-CDG.

}, keywords = {Central Nervous System Neoplasms, Congenital Disorders of Glycosylation, Craniofacial Abnormalities, Developmental Disabilities, Diet, Ketogenic, Drug Resistant Epilepsy, Female, Hemangioma, Humans, Infant, Male, Mannosyltransferases, Twins, Whole Exome Sequencing}, issn = {1872-7131}, doi = {10.1016/j.braindev.2020.04.008}, author = {Paketci, C and Edem, P and Hiz, S and Sonmezler, E and Soydemir, D and Sarikaya Uzan, G and Oktay, Y and O{\textquoteright}Heir, E and Beltran, S and Laurie, S and T{\"o}pf, A and Lochmuller, H and Horvath, R and Yis, U} } @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 {658, title = {De novo variants in congenital diaphragmatic hernia identify MYRF as a new syndrome and reveal genetic overlaps with other developmental disorders.}, journal = {PLoS Genet}, volume = {14}, year = {2018}, month = {2018 12}, pages = {e1007822}, abstract = {

Congenital diaphragmatic hernia (CDH) is a severe birth defect that is often accompanied by other congenital anomalies. Previous exome sequencing studies for CDH have supported a role of de novo damaging variants but did not identify any recurrently mutated genes. To investigate further the genetics of CDH, we analyzed de novo coding variants in 362 proband-parent trios including 271 new trios reported in this study. We identified four unrelated individuals with damaging de novo variants in MYRF (P = 5.3x10(-8)), including one likely gene-disrupting (LGD) and three deleterious missense (D-mis) variants. Eight additional individuals with de novo LGD or missense variants were identified from our other genetic studies or from the literature. Common phenotypes of MYRF de novo variant carriers include CDH, congenital heart disease and genitourinary abnormalities, suggesting that it represents a novel syndrome. MYRF is a membrane associated transcriptional factor highly expressed in developing diaphragm and is depleted of LGD variants in the general population. All de novo missense variants aggregated in two functional protein domains. Analyzing the transcriptome of patient-derived diaphragm fibroblast cells suggest that disease associated variants abolish the transcription factor activity. Furthermore, we showed that the remaining genes with damaging variants in CDH significantly overlap with genes implicated in other developmental disorders. Gene expression patterns and patient phenotypes support pleiotropic effects of damaging variants in these genes on CDH and other developmental disorders. Finally, functional enrichment analysis implicates the disruption of regulation of gene expression, kinase activities, intra-cellular signaling, and cytoskeleton organization as pathogenic mechanisms in CDH.

}, keywords = {Child, Preschool, Developmental Disabilities, DNA Copy Number Variations, Female, Genetic Variation, Heart Defects, Congenital, Hernias, Diaphragmatic, Congenital, Humans, Infant, Newborn, Longitudinal Studies, Male, Membrane Proteins, Mutation, Mutation, Missense, Phenotype, Sequence Analysis, RNA, Syndrome, Transcription Factors, Whole Exome Sequencing, Whole Genome Sequencing}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1007822}, author = {Qi, Hongjian and Yu, Lan and Zhou, Xueya and Wynn, Julia and Zhao, Haoquan and Guo, Yicheng and Zhu, Na and Kitaygorodsky, Alexander and Hernan, Rebecca and Aspelund, Gudrun and Lim, Foong-Yen and Crombleholme, Timothy and Cusick, Robert and Azarow, Kenneth and Danko, Melissa E and Chung, Dai and Warner, Brad W and Mychaliska, George B and Potoka, Douglas and Wagner, Amy J and ElFiky, Mahmoud and Wilson, Jay M and Nickerson, Debbie and Bamshad, Michael and High, Frances A and Longoni, Mauro and Donahoe, Patricia K and Chung, Wendy K and Shen, Yufeng} } @article {500, title = {Genetic variants in components of the NALCN-UNC80-UNC79 ion channel complex cause a broad clinical phenotype (NALCN channelopathies).}, journal = {Hum Genet}, volume = {137}, year = {2018}, month = {2018 Sep}, pages = {753-768}, abstract = {

NALCN is a conserved cation channel, which conducts a permanent sodium leak current and regulates resting membrane potential and neuronal excitability. It is part of a large ion channel complex, the "NALCN channelosome", consisting of multiple proteins including UNC80 and UNC79. The predominant neuronal expression pattern and its function suggest an important role in neuronal function and disease. So far, biallelic NALCN and UNC80 variants have been described in a small number of individuals leading to infantile hypotonia, psychomotor retardation, and characteristic facies 1 (IHPRF1, OMIM 615419) and 2 (IHPRF2, OMIM 616801), respectively. Heterozygous de novo NALCN missense variants in the S5/S6 pore-forming segments lead to congenital contractures of the limbs and face, hypotonia, and developmental delay (CLIFAHDD, OMIM 616266) with some clinical overlap. In this study, we present detailed clinical information of 16 novel individuals with biallelic NALCN variants, 1 individual with a heterozygous de novo NALCN missense variant and an interesting clinical phenotype without contractures, and 12 individuals with biallelic UNC80 variants. We report for the first time a missense NALCN variant~located in the predicted S6 pore-forming unit inherited in an autosomal-recessive manner leading to mild IHPRF1. We show evidence of clinical variability, especially among IHPRF1-affected individuals, and discuss differences between the IHPRF1- and IHPRF2 phenotypes. In summary, we provide a comprehensive overview of IHPRF1 and IHPRF2 phenotypes based on the largest cohort of individuals reported so far and provide additional insights into the clinical phenotypes of these neurodevelopmental diseases to help improve counseling of affected families.

}, keywords = {Adolescent, Adult, Carrier Proteins, Channelopathies, Child, Child, Preschool, Developmental Disabilities, Female, Genetic Markers, Genetic Variation, Humans, Infant, Infant, Newborn, Male, Membrane Proteins, Phenotype, Sodium Channels, Young Adult}, issn = {1432-1203}, doi = {10.1007/s00439-018-1929-5}, author = {Bramswig, Nuria C and Bertoli-Avella, Aida M and Albrecht, Beate and Al Aqeel, Aida I and Alhashem, Amal and Al-Sannaa, Nouriya and Bah, Maissa and Br{\"o}hl, Katharina and Depienne, Christel and Dorison, Nathalie and Doummar, Diane and Ehmke, Nadja and Elbendary, Hasnaa M and Gorokhova, Svetlana and H{\'e}ron, Delphine and Horn, Denise and James, Kiely and Keren, Boris and Kuechler, Alma and Ismail, Samira and Issa, Mahmoud Y and Marey, Isabelle and Mayer, Mich{\`e}le and McEvoy-Venneri, Jennifer and Megarbane, Andre and Mignot, Cyril and Mohamed, Sarar and Nava, Caroline and Philip, Nicole and Ravix, Cecile and Rolfs, Arndt and Sadek, Abdelrahim Abdrabou and Segebrecht, Lara and Stanley, Valentina and Trautman, Camille and Valence, Stephanie and Villard, Laurent and Wieland, Thomas and Engels, Hartmut and Strom, Tim M and Zaki, Maha S and Gleeson, Joseph G and L{\"u}decke, Hermann-Josef and Bauer, Peter and Wieczorek, Dagmar} } @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 {449, title = {Congenital heart defects and left ventricular non-compaction in males with loss-of-function variants in NONO.}, journal = {J Med Genet}, volume = {54}, year = {2017}, month = {2017 01}, pages = {47-53}, abstract = {

BACKGROUND: The non-POU domain containing octamer-binding gene (NONO) is located on chromosome Xq13.1 and encodes a member of a small family of RNA-binding and DNA-binding proteins that perform a variety of tasks involved in RNA synthesis, transcriptional regulation and DNA repair. Loss-of-function variants in NONO have been described as a cause of intellectual disability in males but have not been described in association with congenital heart defects or cardiomyopathy. In this article, we seek to further define the phenotypic consequences of NONO depletion in human subjects.

METHODS: We searched a clinical database of over 6000 individuals referred for exome sequencing and over 60 000 individuals referred for CNV analysis.

RESULTS: We identified two males with atrial and ventricular septal defects, left ventricular non-compaction (LVNC), developmental delay and intellectual disability, who harboured de novo, loss-of-function variants in NONO. We also identified a male infant with developmental delay, congenital brain anomalies and severe LVNC requiring cardiac transplantation, who inherited a single-gene deletion of NONO from his asymptomatic mother.

CONCLUSIONS: We conclude that in addition to global developmental delay and intellectual disability, males with loss-of-function variants in NONO may also be predisposed to developing congenital heart defects and LVNC with the penetrance of these cardiac-related problems being influenced by genetic, epigenetic, environmental or stochastic factors. Brain imaging of males with NONO deficiency may reveal structural defects with abnormalities of the corpus callosum being the most common. Although dysmorphic features vary between affected individuals, relative macrocephaly is a common feature.

}, keywords = {Child, Child, Preschool, Developmental Disabilities, DNA-Binding Proteins, Exome, Heart Defects, Congenital, Heart Ventricles, Humans, Infant, Male, Nuclear Matrix-Associated Proteins, Octamer Transcription Factors, RNA-Binding Proteins}, issn = {1468-6244}, doi = {10.1136/jmedgenet-2016-104039}, author = {Scott, Daryl A and Hernandez-Garcia, Andres and Azamian, Mahshid S and Jordan, Valerie K and Kim, Bum Jun and Starkovich, Molly and Zhang, Jinglan and Wong, Lee-Jun and Darilek, Sandra A and Breman, Amy M and Yang, Yaping and Lupski, James R and Jiwani, Amyn K and Das, Bibhuti and Lalani, Seema R and Iglesias, Alejandro D and Rosenfeld, Jill A and Xia, Fan} } @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 {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 {493, title = {Mutations in GPAA1, Encoding a GPI Transamidase Complex Protein, Cause Developmental Delay, Epilepsy, Cerebellar Atrophy, and Osteopenia.}, journal = {Am J Hum Genet}, volume = {101}, year = {2017}, month = {2017 Nov 02}, pages = {856-865}, abstract = {

Approximately one in every 200 mammalian proteins is anchored to the cell membrane through a glycosylphosphatidylinositol (GPI) anchor. These proteins play important roles notably in neurological development and function. To date, more than 20 genes have been implicated in the biogenesis of GPI-anchored proteins. GPAA1 (glycosylphosphatidylinositol anchor attachment 1) is an essential component of the transamidase complex along with PIGK, PIGS, PIGT, and PIGU (phosphatidylinositol-glycan biosynthesis classes K, S, T, and U, respectively). This complex orchestrates the attachment of the GPI anchor to the C terminus of precursor proteins in the endoplasmic reticulum. Here, we report bi-allelic mutations in GPAA1 in ten individuals from five families. Using whole-exome sequencing, we identified two frameshift mutations (c.981_993del [p.Gln327Hisfs102] and c.920delG [p.Gly307Alafs11]), one intronic splicing mutation (c.1164+5C>T), and six missense mutations (c.152C>T [p.Ser51Leu], c.160_161delinsAA [p.Ala54Asn], c.527G>C [p.Trp176Ser], c.869T>C [p.Leu290Pro], c.872T>C [p.Leu291Pro], and c.1165G>C [p.Ala389Pro]). Most individuals presented with global developmental delay, hypotonia, early-onset seizures, cerebellar atrophy, and osteopenia. The splicing mutation was found to decrease GPAA1 mRNA. Moreover, flow-cytometry analysis of five available individual samples showed that several GPI-anchored proteins had decreased cell-surface abundance in leukocytes (FLAER, CD16, and CD59) or fibroblasts (CD73 and CD109). Transduction of fibroblasts with a lentivirus encoding the wild-type protein partially rescued the deficiency of GPI-anchored proteins. These findings highlight the role of the transamidase complex in the development and function of the cerebellum and the skeletal system.

}, keywords = {Acyltransferases, Adolescent, Adult, Alleles, Atrophy, Bone Diseases, Metabolic, Cerebellum, Child, Child, Preschool, Developmental Disabilities, Epilepsy, Exome, Female, Fibroblasts, Glycosylphosphatidylinositols, Humans, Male, Membrane Glycoproteins, Muscle Hypotonia, Mutation, Pedigree, RNA, Messenger, Seizures}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.09.020}, author = {Nguyen, Thi Tuyet Mai and Murakami, Yoshiko and Sheridan, Eamonn and Ehresmann, Sophie and Rousseau, Justine and St-Denis, Anik and Chai, Guoliang and Ajeawung, Norbert F and Fairbrother, Laura and Reimschisel, Tyler and Bateman, Alexandra and Berry-Kravis, Elizabeth and Xia, Fan and Tardif, Jessica and Parry, David A and Logan, Clare V and Diggle, Christine and Bennett, Christopher P and Hattingh, Louise and Rosenfeld, Jill A and Perry, Michael Scott and Parker, Michael J and Le Deist, Fran{\c c}oise and Zaki, Maha S and Ignatius, Erika and Isohanni, Pirjo and L{\"o}nnqvist, Tuula and Carroll, Christopher J and Johnson, Colin A and Gleeson, Joseph G and Kinoshita, Taroh and Campeau, Philippe M} } @article {355, title = {PRUNE is crucial for normal brain development and mutated in microcephaly with neurodevelopmental impairment.}, journal = {Brain}, volume = {140}, year = {2017}, month = {2017 Apr 01}, pages = {940-952}, abstract = {

PRUNE is a member of the DHH (Asp-His-His) phosphoesterase protein superfamily of molecules important for cell motility, and implicated in cancer progression. Here we investigated multiple families from Oman, India, Iran and Italy with individuals affected by a new autosomal recessive neurodevelopmental and degenerative disorder in which the cardinal features include primary microcephaly and profound global developmental delay. Our genetic studies identified biallelic mutations of PRUNE1 as responsible. Our functional assays of disease-associated variant alleles revealed impaired microtubule polymerization, as well as cell migration and proliferation properties, of mutant PRUNE. Additionally, our studies also highlight a potential new role for PRUNE during microtubule polymerization, which is essential for the cytoskeletal rearrangements that occur during cellular division and proliferation. Together these studies define PRUNE as a molecule fundamental for normal human cortical development and define cellular and clinical consequences associated with PRUNE mutation.

}, keywords = {Adolescent, Brain, Carrier Proteins, Cell Differentiation, Cell Movement, Cerebral Cortex, Child, Child, Preschool, Cytoskeleton, Developmental Disabilities, Female, Genes, Recessive, Heredodegenerative Disorders, Nervous System, Humans, Infant, Male, Microcephaly, Microtubules, Mutation, Pedigree, Young Adult}, issn = {1460-2156}, doi = {10.1093/brain/awx014}, author = {Zollo, Massimo and Ahmed, Mustafa and Ferrucci, Veronica and Salpietro, Vincenzo and Asadzadeh, Fatemeh and Carotenuto, Marianeve and Maroofian, Reza and Al-Amri, Ahmed and Singh, Royana and Scognamiglio, Iolanda and Mojarrad, Majid and Musella, Luca and Duilio, Angela and Di Somma, Angela and Karaca, Ender and Rajab, Anna and Al-Khayat, Aisha and Mohan Mohapatra, Tribhuvan and Eslahi, Atieh and Ashrafzadeh, Farah and Rawlins, Lettie E and Prasad, Rajniti and Gupta, Rashmi and Kumari, Preeti and Srivastava, Mona and Cozzolino, Flora and Kumar Rai, Sunil and Monti, Maria and Harlalka, Gaurav V and Simpson, Michael A and Rich, Philip and Al-Salmi, Fatema and Patton, Michael A and Chioza, Barry A and Efthymiou, Stephanie and Granata, Francesca and Di Rosa, Gabriella and Wiethoff, Sarah and Borgione, Eugenia and Scuderi, Carmela and Mankad, Kshitij and Hanna, Michael G and Pucci, Piero and Houlden, Henry and Lupski, James R and Crosby, Andrew H and Baple, Emma L} } @article {58, title = {Association of MTOR Mutations With Developmental Brain Disorders, Including Megalencephaly, Focal Cortical Dysplasia, and Pigmentary Mosaicism.}, journal = {JAMA Neurol}, volume = {73}, year = {2016}, month = {2016 07 01}, pages = {836-845}, abstract = {

IMPORTANCE: Focal cortical dysplasia (FCD), hemimegalencephaly, and megalencephaly constitute a spectrum of malformations of cortical development with shared neuropathologic features. These disorders are associated with significant childhood morbidity and mortality.

OBJECTIVE: To identify the underlying molecular cause of FCD, hemimegalencephaly, and diffuse megalencephaly.

DESIGN, SETTING, AND PARTICIPANTS: Patients with FCD, hemimegalencephaly, or megalencephaly (mean age, 11.7 years; range, 2-32 years) were recruited from Pediatric Hospital A. Meyer, the University of Hong Kong, and Seattle Children{\textquoteright}s Research Institute from June 2012 to June 2014. Whole-exome sequencing (WES) was performed on 8 children with FCD or hemimegalencephaly using standard-depth (50-60X) sequencing in peripheral samples (blood, saliva, or skin) from the affected child and their parents and deep (150-180X) sequencing in affected brain tissue. Targeted sequencing and WES were used to screen 93 children with molecularly unexplained diffuse or focal brain overgrowth. Histopathologic and functional assays of phosphatidylinositol 3-kinase-AKT (serine/threonine kinase)-mammalian target of rapamycin (mTOR) pathway activity in resected brain tissue and cultured neurons were performed to validate mutations.

MAIN OUTCOMES AND MEASURES: Whole-exome sequencing and targeted sequencing identified variants associated with this spectrum of developmental brain disorders.

RESULTS: Low-level mosaic mutations of MTOR were identified in brain tissue in 4 children with FCD type 2a with alternative allele fractions ranging from 0.012 to 0.086. Intermediate-level mosaic mutation of MTOR (p.Thr1977Ile) was also identified in 3 unrelated children with diffuse megalencephaly and pigmentary mosaicism in skin. Finally, a constitutional de novo mutation of MTOR (p.Glu1799Lys) was identified in 3 unrelated children with diffuse megalencephaly and intellectual disability. Molecular and functional analysis in 2 children with FCD2a from whom multiple affected brain tissue samples were available revealed a mutation gradient with an epicenter in the most epileptogenic area. When expressed in cultured neurons, all MTOR mutations identified here drive constitutive activation of mTOR complex 1 and enlarged neuronal size.

CONCLUSIONS AND RELEVANCE: In this study, mutations of MTOR were associated with a spectrum of brain overgrowth phenotypes extending from FCD type 2a to diffuse megalencephaly, distinguished by different mutations and levels of mosaicism. These mutations may be sufficient to cause cellular hypertrophy in cultured neurons and may provide a demonstration of the pattern of mosaicism in brain and substantiate the link between mosaic mutations of MTOR and pigmentary mosaicism in skin.

}, keywords = {Adolescent, Adult, Amino Acids, Animals, Cells, Cultured, Cerebral Cortex, Child, Child, Preschool, Developmental Disabilities, Embryo, Mammalian, Female, Gene Expression Regulation, Genetic Association Studies, Humans, Intercellular Signaling Peptides and Proteins, Male, Malformations of Cortical Development, Mechanistic Target of Rapamycin Complex 1, Megalencephaly, Mosaicism, Multiprotein Complexes, Mutation, Nerve Tissue Proteins, Neurons, Rats, Retrospective Studies, TOR Serine-Threonine Kinases, Young Adult}, issn = {2168-6157}, doi = {10.1001/jamaneurol.2016.0363}, author = {Mirzaa, Ghayda M and Campbell, Catarina D and Solovieff, Nadia and Goold, Carleton and Jansen, Laura A and Menon, Suchithra and Timms, Andrew E and Conti, Valerio and Biag, Jonathan D and Adams, Carissa and Boyle, Evan August and Collins, Sarah and Ishak, Gisele and Poliachik, Sandra and Girisha, Katta M and Yeung, Kit San and Chung, Brian Hon Yin and Rahikkala, Elisa and Gunter, Sonya A and McDaniel, Sharon S and Macmurdo, Colleen Forsyth and Bernstein, Jonathan A and Martin, Beth and Leary, Rebecca and Mahan, Scott and Liu, Shanming and Weaver, Molly and Doerschner, Michael and Jhangiani, Shalini and Muzny, Donna M and Boerwinkle, Eric and Gibbs, Richard A and Lupski, James R and Shendure, Jay and Saneto, Russell P and Novotny, Edward J and Wilson, Christopher J and Sellers, William R and Morrissey, Michael and Hevner, Robert F and Ojemann, Jeffrey G and Guerrini, Renzo and Murphy, Leon O and Winckler, Wendy and Dobyns, William B} } @article {14, title = {Biallelic Mutations in TMTC3, Encoding a Transmembrane and TPR-Containing Protein, Lead to Cobblestone Lissencephaly.}, journal = {Am J Hum Genet}, volume = {99}, year = {2016}, month = {2016 Nov 03}, pages = {1181-1189}, abstract = {

Cobblestone lissencephaly (COB) is a severe brain malformation in which overmigration of neurons and glial cells into the arachnoid space results in the formation of cortical dysplasia. COB occurs in a wide range of genetic disorders known as dystroglycanopathies, which are congenital muscular dystrophies associated with brain and eye anomalies and range from Walker-Warburg syndrome to Fukuyama congenital muscular dystrophy. Each of these conditions has been associated with alpha-dystroglycan defects or with mutations in genes encoding basement membrane components, which are known to interact with alpha-dystroglycan. Our screening of a cohort of 25 families with recessive forms of COB identified six families affected by biallelic mutations in TMTC3 (encoding transmembrane and tetratricopeptide repeat containing 3), a gene without obvious functional connections to alpha-dystroglycan. Most affected individuals showed brainstem and cerebellum hypoplasia, as well as ventriculomegaly. However, the minority of the affected individuals had eye defects or elevated muscle creatine phosphokinase, separating the TMTC3 COB phenotype from typical congenital muscular dystrophies. Our data suggest that loss of TMTC3 causes COB with minimal eye or muscle involvement.

}, keywords = {Alleles, Amino Acid Sequence, Basement Membrane, Brain, Carrier Proteins, Cerebellum, Cobblestone Lissencephaly, Developmental Disabilities, Dystroglycans, Eye Abnormalities, Female, Humans, Infant, Male, Membrane Proteins, Mutation, Nervous System Malformations, Neuroglia, Neurons, Pedigree, Phenotype}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.09.007}, author = {Jerber, Julie and Zaki, Maha S and Al-Aama, Jumana Y and Rosti, Rasim Ozgur and Ben-Omran, Tawfeg and Dikoglu, Esra and Silhavy, Jennifer L and Caglar, Caner and Musaev, Damir and Albrecht, Beate and Campbell, Kevin P and Willer, Tobias and Almuriekhi, Mariam and {\c C}a{\u g}layan, Ahmet Okay and Vajsar, Jiri and Bilguvar, Kaya and Ogur, Gonul and Abou Jamra, Rami and G{\"u}nel, Murat and Gleeson, Joseph G} } @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 {105, title = {Gene discovery for Mendelian conditions via social networking: de novo variants in KDM1A cause developmental delay and distinctive facial features.}, journal = {Genet Med}, volume = {18}, year = {2016}, month = {2016 08}, pages = {788-95}, abstract = {

PURPOSE: The pace of Mendelian gene discovery is slowed by the "n-of-1 problem"-the difficulty of establishing the causality of a putatively pathogenic variant in a single person or family. Identification of an unrelated person with an overlapping phenotype and suspected pathogenic variant in the same gene can overcome this barrier, but it is often impeded by lack of a convenient or widely available way to share data on candidate variants/genes among families, clinicians, and researchers.

METHODS: Social networking among families, clinicians, and researchers was used to identify three children with variants of unknown significance in KDM1A and similar phenotypes.

RESULTS: De novo variants in KDM1A underlie a new syndrome characterized by developmental delay and distinctive facial features.

CONCLUSION: Social networking is a potentially powerful strategy to discover genes for rare Mendelian conditions, particularly those with nonspecific phenotypic features. To facilitate the efforts of families to share phenotypic and genomic information with each other, clinicians, and researchers, we developed the Repository for Mendelian Genomics Family Portal (RMD-FP; http://uwcmg.org/$\#$/family). Design and development of MyGene2 (http://www.mygene2.org), a Web-based tool that enables families, clinicians, and researchers to search for gene matches based on analysis of phenotype and exome data deposited into the RMD-FP, is under way.Genet Med 18 8, 788-795.

}, keywords = {Child, Child, Preschool, Databases, Factual, Developmental Disabilities, Female, Genetic Association Studies, Histone Demethylases, Humans, Information Dissemination, Male, Mutation, Missense, Phenotype, Social Networking, Web Browser}, issn = {1530-0366}, doi = {10.1038/gim.2015.161}, author = {Chong, Jessica X and Yu, Joon-Ho and Lorentzen, Peter and Park, Karen M and Jamal, Seema M and Tabor, Holly K and Rauch, Anita and Saenz, Margarita Sifuentes and Boltshauser, Eugen and Patterson, Karynne E and Nickerson, Deborah A and Bamshad, Michael J} } @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 {36, title = {KIF5A mutations cause an infantile onset phenotype including severe myoclonus with evidence of mitochondrial dysfunction.}, journal = {Ann Neurol}, volume = {80}, year = {2016}, month = {2016 Oct}, pages = {633-7}, abstract = {

Missense mutations in kinesin family member 5A (KIF5A) cause spastic paraplegia 10. We report on 2 patients with de novo stop-loss frameshift variants in KIF5A resulting in a novel phenotype that includes severe infantile onset myoclonus, hypotonia, optic nerve abnormalities, dysphagia, apnea, and early developmental arrest. We propose that alteration and elongation of the carboxy-terminus of the protein has a dominant-negative effect, causing mitochondrial dysfunction in the setting of an abnormal kinesin "motor." These results highlight the role of expanded testing and whole-exome sequencing in critically ill infants and emphasize the importance of accurate test interpretation. Ann Neurol 2016;80:633-637.

}, keywords = {Apnea, Child, Preschool, Deglutition Disorders, Developmental Disabilities, Fatal Outcome, Female, Frameshift Mutation, Humans, Infant, Kinesins, Male, Mitochondrial Diseases, Muscle Hypotonia, Mutation, Myoclonus, Optic Nerve}, issn = {1531-8249}, doi = {10.1002/ana.24744}, author = {Duis, Jessica and Dean, Shannon and Applegate, Carolyn and Harper, Amy and Xiao, Rui and He, Weimin and Dollar, James D and Sun, Lisa R and Waberski, Marta Biderman and Crawford, Thomas O and Hamosh, Ada and Stafstrom, Carl E} } @article {75, title = {Monoallelic and Biallelic Variants in EMC1 Identified in Individuals with Global Developmental Delay, Hypotonia, Scoliosis, and Cerebellar Atrophy.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Mar 03}, pages = {562-570}, abstract = {

The paradigm of a single gene associated with one specific phenotype and mode of inheritance has been repeatedly challenged. Genotype-phenotype correlations can often be traced to different mutation types, localization of the variants in distinct protein domains, or the trigger of or escape from nonsense-mediated decay. Using whole-exome sequencing, we identified homozygous variants in EMC1 that segregated with a phenotype of developmental delay, hypotonia, scoliosis, and cerebellar atrophy in three families. In addition, a de novo heterozygous EMC1 variant was seen in an individual with a similar clinical and MRI imaging phenotype. EMC1 encodes a member of the endoplasmic reticulum (ER)-membrane protein complex (EMC), an evolutionarily conserved complex that has been proposed to have multiple roles in ER-associated degradation, ER-mitochondria tethering, and proper assembly of multi-pass transmembrane proteins. Perturbations of protein folding and organelle crosstalk have been implicated in neurodegenerative processes including cerebellar atrophy. We propose EMC1 as a gene in which either biallelic or monoallelic variants might lead to a syndrome including intellectual disability and preferential degeneration of the cerebellum.

}, keywords = {Adolescent, Alleles, Amino Acid Sequence, Atrophy, Cerebellum, Child, Child, Preschool, Developmental Disabilities, Endoplasmic Reticulum-Associated Degradation, Female, Genetic Association Studies, Genetic Variation, Heterozygote, Humans, Magnetic Resonance Imaging, Male, Molecular Sequence Data, Muscle Hypotonia, Mutation, Pedigree, Protein Folding, Proteins, Scoliosis}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.01.011}, author = {Harel, Tamar and Yesil, G{\"o}zde and Bayram, Yavuz and Coban-Akdemir, Zeynep and Charng, Wu-Lin and Karaca, Ender and Al Asmari, Ali and Eldomery, Mohammad K and Hunter, Jill V and Jhangiani, Shalini N and Rosenfeld, Jill A and Pehlivan, Davut and El-Hattab, Ayman W and Saleh, Mohammed A and LeDuc, Charles A and Muzny, Donna and Boerwinkle, Eric and Gibbs, Richard A and Chung, Wendy K and Yang, Yaping and Belmont, John W and Lupski, James R} } @article {82, title = {Overlapping 16p13.11 deletion and gain of copies variations associated with childhood onset psychosis include genes with mechanistic implications for autism associated pathways: Two case reports.}, journal = {Am J Med Genet A}, volume = {170A}, year = {2016}, month = {2016 May}, pages = {1165-73}, abstract = {

Copy number variability at 16p13.11 has been associated with intellectual disability, autism, schizophrenia, epilepsy, and attention-deficit hyperactivity disorder. Adolescent/adult- onset psychosis has been reported in a subset of these cases. Here, we report on two children with CNVs in 16p13.11 that developed psychosis before the age of 7. The genotype and neuropsychiatric abnormalities of these patients highlight several overlapping genes that have possible mechanistic relevance to pathways previously implicated in Autism Spectrum Disorders, including the mTOR signaling and the ubiquitin-proteasome cascades. A careful screening of the 16p13.11 region is warranted in patients with childhood onset psychosis.

}, keywords = {Autistic Disorder, Child, Child, Preschool, Chromosome Deletion, Chromosomes, Human, Pair 16, Comparative Genomic Hybridization, Developmental Disabilities, DNA Copy Number Variations, Female, Genetic Association Studies, Humans, Male, Psychotic Disorders, Schizophrenia, Signal Transduction}, issn = {1552-4833}, doi = {10.1002/ajmg.a.37595}, author = {Brownstein, Catherine A and Kleiman, Robin J and Engle, Elizabeth C and Towne, Meghan C and D{\textquoteright}Angelo, Eugene J and Yu, Timothy W and Beggs, Alan H and Picker, Jonathan and Fogler, Jason M and Carroll, Devon and Schmitt, Rachel C O and Wolff, Robert R and Shen, Yiping and Lip, Va and Bilguvar, Kaya and Kim, April and Tembulkar, Sahil and O{\textquoteright}Donnell, Kyle and Gonzalez-Heydrich, Joseph} } @article {21, title = {Recurrent De Novo and Biallelic Variation of ATAD3A, Encoding a Mitochondrial Membrane Protein, Results in Distinct Neurological Syndromes.}, journal = {Am J Hum Genet}, volume = {99}, year = {2016}, month = {2016 Oct 06}, pages = {831-845}, abstract = {

ATPase family AAA-domain containing protein 3A (ATAD3A) is a nuclear-encoded mitochondrial membrane protein implicated in mitochondrial dynamics, nucleoid organization, protein translation, cell growth, and cholesterol metabolism. We identified a recurrent de novo ATAD3A c.1582C>T (p.Arg528Trp) variant by whole-exome sequencing (WES) in five unrelated individuals with a core phenotype of global developmental delay, hypotonia, optic atrophy, axonal neuropathy, and hypertrophic cardiomyopathy. We also describe two families with biallelic variants in ATAD3A, including a homozygous variant in two siblings, and biallelic ATAD3A deletions mediated by nonallelic homologous recombination (NAHR) between ATAD3A and gene family members ATAD3B and ATAD3C. Tissue-specific overexpression of bor, the Drosophila mutation homologous to the human c.1582C>T (p.Arg528Trp) variant, resulted in a dramatic decrease in mitochondrial content, aberrant mitochondrial morphology, and increased autophagy. Homozygous null bor larvae showed a significant decrease of mitochondria, while overexpression of bor resulted in larger, elongated mitochondria. Finally, fibroblasts of an affected individual exhibited increased mitophagy. We conclude that the p.Arg528Trp variant functions through a dominant-negative mechanism that results in small mitochondria that trigger mitophagy, resulting in a reduction in mitochondrial content. ATAD3A variation represents an additional link between mitochondrial dynamics and recognizable neurological syndromes, as seen with MFN2, OPA1, DNM1L, and STAT2 mutations.

}, keywords = {Adenosine Triphosphatases, Adult, Alleles, Animals, ATPases Associated with Diverse Cellular Activities, Axons, Cardiomyopathies, Child, Child, Preschool, Developmental Disabilities, DNA Copy Number Variations, Drosophila melanogaster, Female, Fibroblasts, Homozygote, Humans, Infant, Infant, Newborn, Male, Membrane Proteins, Mitochondria, Mitochondrial Proteins, Muscle Hypotonia, Muscles, Mutation, Nervous System Diseases, Neurons, Optic Atrophy, Phenotype, Polymorphism, Single Nucleotide, Syndrome, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.08.007}, author = {Harel, Tamar and Yoon, Wan Hee and Garone, Caterina and Gu, Shen and Coban-Akdemir, Zeynep and Eldomery, Mohammad K and Posey, Jennifer E and Jhangiani, Shalini N and Rosenfeld, Jill A and Cho, Megan T and Fox, Stephanie and Withers, Marjorie and Brooks, Stephanie M and Chiang, Theodore and Duraine, Lita and Erdin, Serkan and Yuan, Bo and Shao, Yunru and Moussallem, Elie and Lamperti, Costanza and Donati, Maria A and Smith, Joshua D and McLaughlin, Heather M and Eng, Christine M and Walkiewicz, Magdalena and Xia, Fan and Pippucci, Tommaso and Magini, Pamela and Seri, Marco and Zeviani, Massimo and Hirano, Michio and Hunter, Jill V and Srour, Myriam and Zanigni, Stefano and Lewis, Richard Alan and Muzny, Donna M and Lotze, Timothy E and Boerwinkle, Eric and Gibbs, Richard A and Hickey, Scott E and Graham, Brett H and Yang, Yaping and Buhas, Daniela and Martin, Donna M and Potocki, Lorraine and Graziano, Claudio and Bellen, Hugo J and Lupski, James R} } @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 {284, title = {Microcephaly, epilepsy, and neonatal diabetes due to compound heterozygous mutations in IER3IP1: insights into the natural history of a rare disorder.}, journal = {Pediatr Diabetes}, volume = {15}, year = {2014}, month = {2014 May}, pages = {252-6}, abstract = {

Neonatal diabetes mellitus is known to have over 20 different monogenic causes. A syndrome of permanent neonatal diabetes along with primary microcephaly with simplified gyral pattern associated with severe infantile epileptic encephalopathy was recently described in two independent reports in which disease-causing homozygous mutations were identified in the immediate early response-3 interacting protein-1 (IER3IP1) gene. We report here an affected male born to a non-consanguineous couple who was noted to have insulin-requiring permanent neonatal diabetes, microcephaly, and generalized seizures. He was also found to have cortical blindness, severe developmental delay and numerous dysmorphic features. He experienced a slow improvement but not abrogation of seizure frequency and severity on numerous anti-epileptic agents. His clinical course was further complicated by recurrent respiratory tract infections and he died at 8 years of age. Whole exome sequencing was performed on DNA from the proband and parents. He was found to be a compound heterozygote with two different mutations in IER3IP1: p.Val21Gly (V21G) and a novel frameshift mutation p.Phe27fsSer*25. IER3IP1 is a highly conserved protein with marked expression in the cerebral cortex and in beta cells. This is the first reported case of compound heterozygous mutations within IER3IP1 resulting in neonatal diabetes. The triad of microcephaly, generalized seizures, and permanent neonatal diabetes should prompt screening for mutations in IER3IP1. As mutations in genes such as NEUROD1 and PTF1A could cause a similar phenotype, next-generation sequencing approaches-such as exome sequencing reported here-may be an efficient means of uncovering a diagnosis in future cases.

}, keywords = {Amino Acid Substitution, Blindness, Cortical, Carrier Proteins, Developmental Disabilities, Diabetes Mellitus, Epilepsy, Generalized, Fatal Outcome, Frameshift Mutation, Heterozygote, Humans, Infant, Newborn, Infant, Newborn, Diseases, Male, Membrane Proteins, Microcephaly, Neurologic Manifestations, Point Mutation, Severity of Illness Index}, issn = {1399-5448}, doi = {10.1111/pedi.12086}, author = {Shalev, Stavit A and Tenenbaum-Rakover, Yardena and Horovitz, Yoseph and Paz, Veronica P and Ye, Honggang and Carmody, David and Highland, Heather M and Boerwinkle, Eric and Hanis, Craig L and Muzny, Donna M and Gibbs, Richard A and Bell, Graeme I and Philipson, Louis H and Greeley, Siri Atma W} }