@article {1008, title = {SPEN haploinsufficiency causes a neurodevelopmental disorder overlapping proximal 1p36 deletion syndrome with an episignature of X chromosomes in females.}, journal = {Am J Hum Genet}, volume = {108}, year = {2021}, month = {2021 03 04}, pages = {502-516}, abstract = {

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

}, keywords = {Adolescent, Autism Spectrum Disorder, Child, Child, Preschool, Chromosome Deletion, Chromosome Disorders, Chromosomes, Human, Pair 1, Chromosomes, Human, X, DNA Methylation, DNA-Binding Proteins, Epigenesis, Genetic, Female, Haploinsufficiency, Humans, Intellectual Disability, Male, Neurodevelopmental Disorders, Phenotype, RNA-Binding Proteins, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2021.01.015}, author = {Radio, Francesca Clementina and Pang, Kaifang and Ciolfi, Andrea and Levy, Michael A and Hernandez-Garcia, Andres and Pedace, Lucia and Pantaleoni, Francesca and Liu, Zhandong and de Boer, Elke and Jackson, Adam and Bruselles, Alessandro and McConkey, Haley and Stellacci, Emilia and Lo Cicero, Stefania and Motta, Marialetizia and Carrozzo, Rosalba and Dentici, Maria Lisa and McWalter, Kirsty and Desai, Megha and Monaghan, Kristin G and Telegrafi, Aida and Philippe, Christophe and Vitobello, Antonio and Au, Margaret and Grand, Katheryn and Sanchez-Lara, Pedro A and Baez, Joanne and Lindstrom, Kristin and Kulch, Peggy and Sebastian, Jessica and Madan-Khetarpal, Suneeta and Roadhouse, Chelsea and MacKenzie, Jennifer J and Monteleone, Berrin and Saunders, Carol J and Jean Cuevas, July K and Cross, Laura and Zhou, Dihong and Hartley, Taila and Sawyer, Sarah L and Monteiro, Fabiola Paoli and Secches, Tania Vertemati and Kok, Fernando and Schultz-Rogers, Laura E and Macke, Erica L and Morava, Eva and Klee, Eric W and Kemppainen, Jennifer and Iascone, Maria and Selicorni, Angelo and Tenconi, Romano and Amor, David J and Pais, Lynn and Gallacher, Lyndon and Turnpenny, Peter D and Stals, Karen and Ellard, Sian and Cabet, Sara and Lesca, Gaetan and Pascal, Joset and Steindl, Katharina and Ravid, Sarit and Weiss, Karin and Castle, Alison M R and Carter, Melissa T and Kalsner, Louisa and de Vries, Bert B A and van Bon, Bregje W and Wevers, Marijke R and Pfundt, Rolph and Stegmann, Alexander P A and Kerr, Bronwyn and Kingston, Helen M and Chandler, Kate E and Sheehan, Willow and Elias, Abdallah F and Shinde, Deepali N and Towne, Meghan C and Robin, Nathaniel H and Goodloe, Dana and Vanderver, Adeline and Sherbini, Omar and Bluske, Krista and Hagelstrom, R Tanner and Zanus, Caterina and Faletra, Flavio and Musante, Luciana and Kurtz-Nelson, Evangeline C and Earl, Rachel K and Anderlid, Britt-Marie and Morin, Gilles and van Slegtenhorst, Marjon and Diderich, Karin E M and Brooks, Alice S and Gribnau, Joost and Boers, Ruben G and Finestra, Teresa Robert and Carter, Lauren B and Rauch, Anita and Gasparini, Paolo and Boycott, Kym M and Barakat, Tahsin Stefan and GrAHm, John M and Faivre, Laurence and Banka, Siddharth and Wang, Tianyun and Eichler, Evan E and Priolo, Manuela and Dallapiccola, Bruno and Vissers, Lisenka E L M and Sadikovic, Bekim and Scott, Daryl A and Holder, Jimmy Lloyd and Tartaglia, Marco} } @article {570, title = {TBX6 compound inheritance leads to congenital vertebral malformations in humans and mice.}, journal = {Hum Mol Genet}, volume = {28}, year = {2019}, month = {2019 02 15}, pages = {539-547}, abstract = {

Congenital vertebral malformations (CVMs) are associated with human TBX6 compound inheritance that combines a rare null allele and a common hypomorphic allele at the TBX6 locus. Our previous in vitro evidence suggested that this compound inheritance resulted in a TBX6 gene dosage of less than haploinsufficiency (i.e. <50\%) as a potential mechanism of TBX6-associated CVMs. To further investigate this pathogenetic model, we ascertained and collected 108 Chinese CVM cases and found that 10 (9.3\%) of them carried TBX6 null mutations in combination with common hypomorphic variants at the second TBX6 allele. For in vivo functional verification and genetic analysis of TBX6 compound inheritance, we generated both null and hypomorphic mutations in mouse Tbx6 using the CRISPR-Cas9 method. These Tbx6 mutants are not identical to the patient variants at the DNA sequence level, but instead functionally mimic disease-associated TBX6 variants. Intriguingly, as anticipated by the compound inheritance model, a high penetrance of CVM phenotype was only observed in the mice with combined null and hypomorphic alleles of Tbx6. These findings are consistent with our experimental observations in humans and supported the dosage effect of TBX6 in CVM etiology. In conclusion, our findings in the newly collected human CVM subjects and Tbx6 mouse models consistently support the contention that TBX6 compound inheritance causes CVMs, potentially via a gene dosage-dependent mechanism. Furthermore, mouse Tbx6 mutants mimicking human CVM-associated variants will be useful models for further mechanistic investigations of CVM pathogenesis in the cases associated with TBX6.

}, keywords = {Adolescent, Alleles, Animals, Child, Child, Preschool, Congenital Abnormalities, CRISPR-Cas Systems, Disease Models, Animal, Female, Haploinsufficiency, Humans, Infant, Male, Mice, Mutation, Phenotype, Scoliosis, Spine, T-Box Domain Proteins}, issn = {1460-2083}, doi = {10.1093/hmg/ddy358}, author = {Yang, Nan and Wu, Nan and Zhang, Ling and Zhao, Yanxue and Liu, Jiaqi and Liang, Xiangyu and Ren, Xiaojun and Li, Weiyu and Chen, Weisheng and Dong, Shuangshuang and Zhao, Sen and Lin, Jiachen and Xiang, Hang and Xue, Huadan and Chen, Lu and Sun, Hao and Zhang, Jianguo and Shi, Jiangang and Zhang, Shuyang and Lu, Daru and Wu, Xiaohui and Jin, Li and Ding, Jiandong and Qiu, Guixing and Wu, Zhihong and Lupski, James R and Zhang, Feng} } @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 {350, title = {Genetic Drivers of Kidney Defects in the DiGeorge Syndrome.}, journal = {N Engl J Med}, volume = {376}, year = {2017}, month = {2017 02 23}, pages = {742-754}, abstract = {

BACKGROUND: The DiGeorge syndrome, the most common of the microdeletion syndromes, affects multiple organs, including the heart, the nervous system, and the kidney. It is caused by deletions on chromosome 22q11.2; the genetic driver of the kidney defects is unknown.

METHODS: We conducted a genomewide search for structural variants in two cohorts: 2080 patients with congenital kidney and urinary tract anomalies and 22,094 controls. We performed exome and targeted resequencing in samples obtained from 586 additional patients with congenital kidney anomalies. We also carried out functional studies using zebrafish and mice.

RESULTS: We identified heterozygous deletions of 22q11.2 in 1.1\% of the patients with congenital kidney anomalies and in 0.01\% of population controls (odds ratio, 81.5; P=4.5{\texttimes}10). We localized the main drivers of renal disease in the DiGeorge syndrome to a 370-kb region containing nine genes. In zebrafish embryos, an induced loss of function in snap29, aifm3, and crkl resulted in renal defects; the loss of crkl alone was sufficient to induce defects. Five of 586 patients with congenital urinary anomalies had newly identified, heterozygous protein-altering variants, including a premature termination codon, in CRKL. The inactivation of Crkl in the mouse model induced developmental defects similar to those observed in patients with congenital urinary anomalies.

CONCLUSIONS: We identified a recurrent 370-kb deletion at the 22q11.2 locus as a driver of kidney defects in the DiGeorge syndrome and in sporadic congenital kidney and urinary tract anomalies. Of the nine genes at this locus, SNAP29, AIFM3, and CRKL appear to be critical to the phenotype, with haploinsufficiency of CRKL emerging as the main genetic driver. (Funded by the National Institutes of Health and others.).

}, keywords = {Adaptor Proteins, Signal Transducing, Adolescent, Animals, Child, Chromosome Deletion, Chromosomes, Human, Pair 22, DiGeorge Syndrome, Exome, Female, Haploinsufficiency, Heterozygote, Humans, Infant, Infant, Newborn, Kidney, Male, Mice, Models, Animal, Nuclear Proteins, Sequence Analysis, DNA, Urinary Tract, Young Adult, Zebrafish}, issn = {1533-4406}, doi = {10.1056/NEJMoa1609009}, author = {Lopez-Rivera, Esther and Liu, Yangfan P and Verbitsky, Miguel and Anderson, Blair R and Capone, Valentina P and Otto, Edgar A and Yan, Zhonghai and Mitrotti, Adele and Martino, Jeremiah and Steers, Nicholas J and Fasel, David A and Vukojevic, Katarina and Deng, Rong and Racedo, Silvia E and Liu, Qingxue and Werth, Max and Westland, Rik and Vivante, Asaf and Makar, Gabriel S and Bodria, Monica and Sampson, Matthew G and Gillies, Christopher E and Vega-Warner, Virginia and Maiorana, Mariarosa and Petrey, Donald S and Honig, Barry and Lozanovski, Vladimir J and Salomon, R{\'e}mi and Heidet, Laurence and Carpentier, Wassila and Gaillard, Dominique and Carrea, Alba and Gesualdo, Loreto and Cusi, Daniele and Izzi, Claudia and Scolari, Francesco and van Wijk, Joanna A E and Arapovic, Adela and Saraga-Babic, Mirna and Saraga, Marijan and Kunac, Nenad and Samii, Ali and McDonald-McGinn, Donna M and Crowley, Terrence B and Zackai, Elaine H and Drozdz, Dorota and Miklaszewska, Monika and Tkaczyk, Marcin and Sikora, Przemyslaw and Szczepanska, Maria and Mizerska-Wasiak, Malgorzata and Krzemien, Grazyna and Szmigielska, Agnieszka and Zaniew, Marcin and Darlow, John M and Puri, Prem and Barton, David and Casolari, Emilio and Furth, Susan L and Warady, Bradley A and Gucev, Zoran and Hakonarson, Hakon and Flogelova, Hana and Tasic, Velibor and Latos-Bielenska, Anna and Materna-Kiryluk, Anna and Allegri, Landino and Wong, Craig S and Drummond, Iain A and D{\textquoteright}Agati, Vivette and Imamoto, Akira and Barasch, Jonathan M and Hildebrandt, Friedhelm and Kiryluk, Krzysztof and Lifton, Richard P and Morrow, Bernice E and Jeanpierre, Cecile and Papaioannou, Virginia E and Ghiggeri, Gian Marco and Gharavi, Ali G and Katsanis, Nicholas and Sanna-Cherchi, Simone} } @article {369, title = {Haploinsufficiency of the E3 ubiquitin-protein ligase gene TRIP12 causes intellectual disability with or without autism spectrum disorders, speech delay, and dysmorphic features.}, journal = {Hum Genet}, volume = {136}, year = {2017}, month = {2017 04}, pages = {377-386}, abstract = {

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

}, keywords = {Adolescent, Autism Spectrum Disorder, Carrier Proteins, Child, Child, Preschool, Cohort Studies, DNA Copy Number Variations, Facies, Female, Haploinsufficiency, Humans, Infant, Intellectual Disability, Language Development Disorders, Male, Ubiquitin-Protein Ligases}, issn = {1432-1203}, doi = {10.1007/s00439-017-1763-1}, author = {Zhang, Jing and Gambin, Tomasz and Yuan, Bo and Szafranski, Przemyslaw and Rosenfeld, Jill A and Balwi, Mohammed Al and Alswaid, Abdulrahman and Al-Gazali, Lihadh and Shamsi, Aisha M Al and Komara, Makanko and Ali, Bassam R and Roeder, Elizabeth and McAuley, Laura and Roy, Daniel S and Manchester, David K and Magoulas, Pilar and King, Lauren E and Hannig, Vickie and Bonneau, Dominique and Denomm{\'e}-Pichon, Anne-Sophie and Charif, Majida and Besnard, Thomas and B{\'e}zieau, St{\'e}phane and Cogn{\'e}, Benjamin and Andrieux, Joris and Zhu, Wenmiao and He, Weimin and Vetrini, Francesco and Ward, Patricia A and Cheung, Sau Wai and Bi, Weimin and Eng, Christine M and Lupski, James R and Yang, Yaping and Patel, Ankita and Lalani, Seema R and Xia, Fan and Stankiewicz, Pawe{\l}} } @article {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 {41, title = {Nonrecurrent PMP22-RAI1 contiguous gene deletions arise from replication-based mechanisms and result in Smith-Magenis syndrome with evident peripheral neuropathy.}, journal = {Hum Genet}, volume = {135}, year = {2016}, month = {2016 Oct}, pages = {1161-74}, abstract = {

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

}, keywords = {Adolescent, Adult, Child, Child, Preschool, Chromosomes, Human, Pair 17, DNA Copy Number Variations, DNA Replication, Female, Gene Deletion, Haploinsufficiency, Homologous Recombination, Humans, Intellectual Disability, Male, Mutation, Myelin Proteins, Smith-Magenis Syndrome, Trans-Activators, Transcription Factors}, issn = {1432-1203}, doi = {10.1007/s00439-016-1703-5}, author = {Yuan, Bo and Neira, Juanita and Gu, Shen and Harel, Tamar and Liu, Pengfei and Brice{\~n}o, Ignacio and Elsea, Sarah H and G{\'o}mez, Alberto and Potocki, Lorraine and Lupski, James R} } @article {109, title = {Mutations in Either TUBB or MAPRE2 Cause Circumferential Skin Creases Kunze Type.}, journal = {Am J Hum Genet}, volume = {97}, year = {2015}, month = {2015 Dec 03}, pages = {790-800}, abstract = {

Circumferential skin creases Kunze type (CSC-KT) is a specific congenital entity with an unknown genetic cause. The disease phenotype comprises characteristic circumferential skin creases accompanied by intellectual disability, a cleft palate, short stature, and dysmorphic features. Here, we report that mutations in either MAPRE2 or TUBB underlie the genetic origin of this syndrome. MAPRE2 encodes a member of the microtubule end-binding family of proteins that bind to the guanosine triphosphate cap at growing microtubule plus ends, and TUBB encodes a β-tubulin isotype that is expressed abundantly in the developing brain. Functional analyses of the TUBB mutants show multiple defects in the chaperone-dependent tubulin heterodimer folding and assembly pathway that leads to a compromised yield of native heterodimers. The TUBB mutations also have an impact on microtubule dynamics. For MAPRE2, we show that the mutations result in enhanced MAPRE2 binding to microtubules, implying an increased dwell time at microtubule plus ends. Further, in vivo analysis of MAPRE2 mutations in a zebrafish model of craniofacial development shows that the variants most likely perturb the patterning of branchial arches, either through excessive activity (under a recessive paradigm) or through haploinsufficiency (dominant de novo paradigm). Taken together, our data add CSC-KT to the growing list of tubulinopathies and highlight how multiple inheritance paradigms can affect dosage-sensitive biological systems so as to result in the same clinical defect.

}, keywords = {Adolescent, Animals, Brain, Child, Cutis Laxa, Female, Gene Dosage, Gene Expression Regulation, Developmental, Genes, Recessive, Hamartoma, Haploinsufficiency, Humans, Infant, Inheritance Patterns, Male, Microtubule-Associated Proteins, Microtubules, Mutation, Protein Folding, Protein Multimerization, Skin, Skin Abnormalities, Tubulin, Young Adult, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.10.014}, author = {Isrie, Mala and Breuss, Martin and Tian, Guoling and Hansen, Andi Harley and Cristofoli, Francesca and Morandell, Jasmin and Kupchinsky, Zachari A and Sifrim, Alejandro and Rodriguez-Rodriguez, Celia Maria and Dapena, Elena Porta and Doonanco, Kurston and Leonard, Norma and Tinsa, Faten and Moortgat, St{\'e}phanie and Ulucan, Hakan and Koparir, Erkan and Karaca, Ender and Katsanis, Nicholas and Marton, Valeria and Vermeesch, Joris Robert and Davis, Erica E and Cowan, Nicholas J and Keays, David Anthony and Van Esch, Hilde} } @article {258, title = {Expanding the phenotypic spectrum of ARID1B-mediated disorders and identification of altered cell-cycle dynamics due to ARID1B haploinsufficiency.}, journal = {Orphanet J Rare Dis}, volume = {9}, year = {2014}, month = {2014 Mar 27}, pages = {43}, abstract = {

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

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

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

}, keywords = {Abnormalities, Multiple, Cell Cycle, Chromatin Assembly and Disassembly, DNA-Binding Proteins, Face, Female, Hand Deformities, Congenital, Haploinsufficiency, Humans, Intellectual Disability, Male, Micrognathism, Neck, Transcription Factors}, issn = {1750-1172}, doi = {10.1186/1750-1172-9-43}, author = {Sim, Joe C H and White, Susan M and Fitzpatrick, Elizabeth and Wilson, Gabrielle R and Gillies, Greta and Pope, Kate and Mountford, Hayley S and Torring, Pernille M and McKee, Shane and Vulto-van Silfhout, Anneke T and Jhangiani, Shalini N and Muzny, Donna M and Leventer, Richard J and Delatycki, Martin B and Amor, David J and Lockhart, Paul J} } @article {290, title = {Evidence for replicative mechanism in a CHD7 rearrangement in a patient with CHARGE syndrome.}, journal = {Am J Med Genet A}, volume = {161A}, year = {2013}, month = {2013 Dec}, pages = {3182-6}, abstract = {

Haploinsufficiency of CHD7 (OMIM$\#$ 608892) is known to cause CHARGE syndrome (OMIM$\#$ 214800). Molecular testing supports a definitive diagnosis in approximately 65-70\% of cases. Most CHD7 mutations arise de novo, and no mutations affecting exon-7 have been reported to date. We report on an 8-year-old girl diagnosed with CHARGE syndrome that was referred to our laboratory for comprehensive CHD7 gene screening. Genomic DNA from the subject with a suspected diagnosis of CHARGE was isolated from peripheral blood lymphocytes and comprehensive Sanger sequencing, along with deletion/duplication analysis of the CHD7 gene using multiplex ligation-dependent probe amplification (MLPA), was performed. MLPA analysis identified a reduced single probe signal for exon-7 of the CHD7 gene consistent with potential heterozygous deletion. Long-range PCR breakpoint analysis identified a complex genomic rearrangement (CGR) leading to the deletion of exon-7 and breakpoints consistent with a replicative mechanism such as fork stalling and template switching (FoSTeS) or microhomology-mediated break-induced replication (MMBIR). Taken together this represents the first evidence for a CHD7 intragenic CGR in a patient with CHARGE syndrome leading to what appears to be also the first report of a mutation specifically disrupting exon-7. Although likely rare, CGR may represent an overlooked mechanism in subjects with CHARGE syndrome that can be missed by current sequencing and dosage assays.

}, keywords = {Abnormalities, Multiple, CHARGE Syndrome, Child, DNA Helicases, DNA Replication, DNA-Binding Proteins, Exons, Female, Gene Deletion, Haploinsufficiency, Humans, Mutation}, issn = {1552-4833}, doi = {10.1002/ajmg.a.36178}, author = {Vatta, Matteo and Niu, Zhiyv and Lupski, James R and Putnam, Philip and Spoonamore, Katherine G and Fang, Ping and Eng, Christine M and Willis, Alecia S} } @article {327, title = {Haploinsufficiency of SF3B4, a component of the pre-mRNA spliceosomal complex, causes Nager syndrome.}, journal = {Am J Hum Genet}, volume = {90}, year = {2012}, month = {2012 May 04}, pages = {925-33}, abstract = {

Nager syndrome, first described more than 60 years ago, is the archetype of a class of disorders called the acrofacial dysostoses, which are characterized by craniofacial and limb malformations. Despite intensive efforts, no gene for Nager syndrome has yet been identified. In an international collaboration, FORGE Canada and the National Institutes of Health Centers for Mendelian Genomics used exome sequencing as a discovery tool and found that mutations in SF3B4, a component of the U2 pre-mRNA spliceosomal complex, cause Nager syndrome. After Sanger sequencing of SF3B4 in a validation cohort, 20 of 35 (57\%) families affected by Nager syndrome had 1 of 18 different mutations, nearly all of which were frameshifts. These results suggest that most cases of Nager syndrome are caused by haploinsufficiency of SF3B4. Our findings add Nager syndrome to a growing list of disorders caused by mutations in genes that encode major components of the spliceosome and also highlight the synergistic potential of international collaboration when exome sequencing is applied in the search for genes responsible for rare Mendelian phenotypes.

}, keywords = {Adult, Child, Child, Preschool, Cohort Studies, Exome, Female, Haploinsufficiency, Humans, Limb Deformities, Congenital, Male, Mandibulofacial Dysostosis, Mutation, Reproducibility of Results, RNA Precursors, RNA Splicing Factors, RNA-Binding Proteins, Spliceosomes, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2012.04.004}, author = {Bernier, Francois P and Caluseriu, Oana and Ng, Sarah and Schwartzentruber, Jeremy and Buckingham, Kati J and Innes, A Micheil and Jabs, Ethylin Wang and Innis, Jeffrey W and Schuette, Jane L and Gorski, Jerome L and Byers, Peter H and Andelfinger, Gregor and Siu, Victoria and Lauzon, Julie and Fernandez, Bridget A and McMillin, Margaret and Scott, Richard H and Racher, Hilary and Majewski, Jacek and Nickerson, Deborah A and Shendure, Jay and Bamshad, Michael J and Parboosingh, Jillian S} } @article {324, title = {Loss-of-function mutations in TGFB2 cause a syndromic presentation of thoracic aortic aneurysm.}, journal = {Nat Genet}, volume = {44}, year = {2012}, month = {2012 Jul 08}, pages = {922-7}, abstract = {

Loeys-Dietz syndrome (LDS) associates with a tissue signature for high transforming growth factor (TGF)-β signaling but is often caused by heterozygous mutations in genes encoding positive effectors of TGF-β signaling, including either subunit of the TGF-β receptor or SMAD3, thereby engendering controversy regarding the mechanism of disease. Here, we report heterozygous mutations or deletions in the gene encoding the TGF-β2 ligand for a phenotype within the LDS spectrum and show upregulation of TGF-β signaling in aortic tissue from affected individuals. Furthermore, haploinsufficient Tgfb2(+/-) mice have aortic root aneurysm and biochemical evidence of increased canonical and noncanonical TGF-β signaling. Mice that harbor both a mutant Marfan syndrome (MFS) allele (Fbn1(C1039G/+)) and Tgfb2 haploinsufficiency show increased TGF-β signaling and phenotypic worsening in association with normalization of TGF-β2 expression and high expression of TGF-β1. Taken together, these data support the hypothesis that compensatory autocrine and/or paracrine events contribute to the pathogenesis of TGF-β-mediated vasculopathies.

}, keywords = {Animals, Aortic Aneurysm, Thoracic, Disease Models, Animal, Female, Fibrillin-1, Fibrillins, Haploinsufficiency, Humans, Loeys-Dietz Syndrome, Male, Marfan Syndrome, Mice, Mice, Knockout, Mice, Mutant Strains, Microfilament Proteins, Mutation, Pedigree, Phenotype, Signal Transduction, Syndrome, Transforming Growth Factor beta2}, issn = {1546-1718}, doi = {10.1038/ng.2349}, author = {Lindsay, Mark E and Schepers, Dorien and Bolar, Nikhita Ajit and Doyle, Jefferson J and Gallo, Elena and Fert-Bober, Justyna and Kempers, Marlies J E and Fishman, Elliot K and Chen, Yichun and Myers, Loretha and Bjeda, Djahita and Oswald, Gretchen and Elias, Abdallah F and Levy, Howard P and Anderlid, Britt-Marie and Yang, Margaret H and Bongers, Ernie M H F and Timmermans, Janneke and Braverman, Alan C and Canham, Natalie and Mortier, Geert R and Brunner, Han G and Byers, Peter H and Van Eyk, Jennifer and Van Laer, Lut and Dietz, Harry C and Loeys, Bart L} }