@article {391, title = {Heterozygous variants in ACTL6A, encoding a component of the BAF complex, are associated with intellectual disability.}, journal = {Hum Mutat}, volume = {38}, year = {2017}, month = {2017 10}, pages = {1365-1371}, abstract = {

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

}, keywords = {Actins, Adolescent, Child, Chromatin Assembly and Disassembly, Chromosomal Proteins, Non-Histone, DNA Helicases, DNA-Binding Proteins, Exome, Face, Female, Hand Deformities, Congenital, Heterozygote, Humans, Intellectual Disability, Male, Micrognathism, Multiprotein Complexes, Mutation, Missense, Nuclear Proteins, Protein Binding, Transcription Factors}, issn = {1098-1004}, doi = {10.1002/humu.23282}, author = {Marom, Ronit and Jain, Mahim and Burrage, Lindsay C and Song, I-Wen and Graham, Brett H and Brown, Chester W and Stevens, Servi J C and Stegmann, Alexander P A and Gunter, Andrew T and Kaplan, Julie D and Gavrilova, Ralitza H and Shinawi, Marwan and Rosenfeld, Jill A and Bae, Yangjin and Tran, Alyssa A and Chen, Yuqing and Lu, James T and Gibbs, Richard A and Eng, Christine and Yang, Yaping and Rousseau, Justine and de Vries, Bert B A and Campeau, Philippe M and Lee, Brendan} } @article {359, title = {Kaufman oculo-cerebro-facial syndrome in a child with small and absent terminal phalanges and absent nails.}, journal = {J Hum Genet}, volume = {62}, year = {2017}, month = {2017 Apr}, pages = {465-471}, abstract = {

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

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

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

}, keywords = {Adolescent, Adult, Amino Acid Substitution, Ataxia, Child, Child, Preschool, Chromatin, Cyclin-Dependent Kinase Inhibitor p21, Developmental Disabilities, Exome, Face, Female, Gene Expression Regulation, Genes, Reporter, HEK293 Cells, Humans, Intellectual Disability, Language Development Disorders, Male, Models, Molecular, Mosaicism, Mutation, Neurodevelopmental Disorders, Protein Transport, Syndrome, Transcription Factors, Transcription, Genetic}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.11.012}, author = {Harms, Frederike Leonie and Girisha, Katta M and Hardigan, Andrew A and Kort{\"u}m, Fanny and Shukla, Anju and Alawi, Malik and Dalal, Ashwin and Brady, Lauren and Tarnopolsky, Mark and Bird, Lynne M and Ceulemans, Sophia and Bebin, Martina and Bowling, Kevin M and Hiatt, Susan M and Lose, Edward J and Primiano, Michelle and Chung, Wendy K and Juusola, Jane and Akdemir, Zeynep C and Bainbridge, Matthew and Charng, Wu-Lin and Drummond-Borg, Margaret and Eldomery, Mohammad K and El-Hattab, Ayman W and Saleh, Mohammed A M and B{\'e}zieau, St{\'e}phane and Cogn{\'e}, Benjamin and Isidor, Bertrand and K{\"u}ry, S{\'e}bastien and Lupski, James R and Myers, Richard M and Cooper, Gregory M and Kutsche, Kerstin} } @article {433, title = {Patients with a Kabuki syndrome phenotype demonstrate DNA methylation abnormalities.}, journal = {Eur J Hum Genet}, volume = {25}, year = {2017}, month = {2017 12}, pages = {1335-1344}, abstract = {

Kabuki syndrome is a monogenic disorder caused by loss of function variants in either of two genes encoding histone-modifying enzymes. We performed targeted sequencing in a cohort of 27 probands with a clinical diagnosis of Kabuki syndrome. Of these, 12 had causative variants in the two known Kabuki syndrome genes. In 2, we identified presumptive loss of function de novo variants in KMT2A (missense and splice site variants), a gene that encodes another histone modifying enzyme previously exclusively associated with Wiedermann-Steiner syndrome. Although Kabuki syndrome is a disorder of histone modification, we also find alterations in DNA methylation among individuals with a Kabuki syndrome diagnosis relative to matched normal controls, regardless of whether they carry a variant in KMT2A or KMT2D or not. Furthermore, we observed characteristic global abnormalities of DNA methylation that distinguished patients with a loss of function variant in KMT2D or missense or splice site variants in either KMT2D or KMT2A from normal controls. Our results provide new insights into the relationship of genotype to epigenotype and phenotype and indicate cross-talk between histone and DNA methylation machineries exposed by inborn errors of the epigenetic apparatus.

}, keywords = {Abnormalities, Multiple, Case-Control Studies, Child, DNA Methylation, Face, Female, Hematologic Diseases, Histone-Lysine N-Methyltransferase, Humans, Loss of Function Mutation, Male, Myeloid-Lymphoid Leukemia Protein, Phenotype, Vestibular Diseases}, issn = {1476-5438}, doi = {10.1038/s41431-017-0023-0}, author = {Sobreira, Nara and Brucato, Martha and Zhang, Li and Ladd-Acosta, Christine and Ongaco, Chrissie and Romm, Jane and Doheny, Kimberly F and Mingroni-Netto, Regina C and Bertola, D{\'e}bora and Kim, Chong A and Perez, Ana Ba and Melaragno, Maria I and Valle, David and Meloni, Vera A and Bjornsson, Hans T} } @article {442, title = {Phenotypic and molecular characterisation of CDK13-related congenital heart defects, dysmorphic facial features and intellectual developmental disorders.}, journal = {Genome Med}, volume = {9}, year = {2017}, month = {2017 08 14}, pages = {73}, abstract = {

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

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

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

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

}, keywords = {Adolescent, Adult, CDC2 Protein Kinase, Child, Child, Preschool, Face, Female, Heart Defects, Congenital, Humans, Infant, Intellectual Disability, Male, Mutation, Phenotype, Syndrome}, issn = {1756-994X}, doi = {10.1186/s13073-017-0463-8}, author = {Bostwick, Bret L and McLean, Scott and Posey, Jennifer E and Streff, Haley E and Gripp, Karen W and Blesson, Alyssa and Powell-Hamilton, Nina and Tusi, Jessica and Stevenson, David A and Farrelly, Ellyn and Hudgins, Louanne and Yang, Yaping and Xia, Fan and Wang, Xia and Liu, Pengfei and Walkiewicz, Magdalena and McGuire, Marianne and Grange, Dorothy K and Andrews, Marisa V and Hummel, Marybeth and Madan-Khetarpal, Suneeta and Infante, Elena and Coban-Akdemir, Zeynep and Miszalski-Jamka, Karol and Jefferies, John L and Rosenfeld, Jill A and Emrick, Lisa and Nugent, Kimberly M and Lupski, James R and Belmont, John W and Lee, Brendan and Lalani, Seema R} } @article {362, title = {Presynaptic congenital myasthenic syndrome with a homozygous sequence variant in LAMA5 combines myopia, facial tics, and failure of neuromuscular transmission.}, journal = {Am J Med Genet A}, volume = {173}, year = {2017}, month = {2017 Aug}, pages = {2240-2245}, abstract = {

Defects in genes encoding the isoforms of the laminin alpha subunit have been linked to various phenotypic manifestations, including brain malformations, muscular dystrophy, ocular defects, cardiomyopathy, and skin abnormalities. We report here a severe defect of neuromuscular transmission in a consanguineous patient with a homozygous variant in the laminin alpha-5 subunit gene (LAMA5). The variant c.8046C>T (p.Arg2659Trp) is rare and has a predicted deleterious effect. The affected individual, who also carries a rare homozygous sequence variant in LAMA1, had muscle weakness, myopia, and facial tics. Magnetic resonance imaging of brain showed mild volume loss and periventricular T2 prolongation. Repetitive nerve stimulation revealed 50\% decrement of compound muscle action potential amplitudes and 250\% facilitation immediately after exercise, Endplate studies identified a profound reduction of the endplate potential quantal content and endplates with normal postsynaptic folding that were denuded or partially occupied by small nerve terminals. Expression studies revealed that p.Arg2659Trp caused decreased binding of laminin alpha-5 to SV2A and impaired laminin-521 cell-adhesion and cell projection support in primary neuronal cultures. In summary, this report describing severe neuromuscular transmission failure in a patient with a LAMA5 mutation expands the list of phenotypes associated with defects in genes encoding alpha-laminins.

}, keywords = {Adult, Face, Female, Homozygote, Humans, Laminin, Myasthenic Syndromes, Congenital, Myopia, Neuromuscular Junction Diseases, Tics, Young Adult}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38291}, author = {Maselli, Ricardo A and Arredondo, Juan and V{\'a}zquez, Jessica and Chong, Jessica X and Bamshad, Michael J and Nickerson, Deborah A and Lara, Marian and Ng, Fiona and Lo, Victoria L and Pytel, Peter and McDonald, Craig M} } @article {126, title = {Gonadal mosaicism in ARID1B gene causes intellectual disability and dysmorphic features in three siblings.}, journal = {Am J Med Genet A}, volume = {170A}, year = {2016}, month = {2016 Jan}, pages = {156-61}, abstract = {

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

}, keywords = {Abnormalities, Multiple, Adolescent, Child, DNA-Binding Proteins, Exome, Face, Female, Hand Deformities, Congenital, Heterozygote, Humans, Intellectual Disability, Male, Micrognathism, Mosaicism, Mutation, Neck, Pedigree, Siblings, Transcription Factors}, issn = {1552-4833}, doi = {10.1002/ajmg.a.37405}, author = {Ben-Salem, Salma and Sobreira, Nara and Akawi, Nadia A and Al-Shamsi, Aisha M and John, Anne and Pramathan, Thachillath and Valle, David and Ali, Bassam R and Al-Gazali, Lihadh} } @article {194, title = {De novo mutations in NALCN cause a syndrome characterized by congenital contractures of the limbs and face, hypotonia, and developmental delay.}, journal = {Am J Hum Genet}, volume = {96}, year = {2015}, month = {2015 Mar 05}, pages = {462-73}, abstract = {

Freeman-Sheldon syndrome, or distal arthrogryposis type 2A (DA2A), is an autosomal-dominant condition caused by mutations in MYH3 and characterized by multiple congenital contractures of the face and limbs and normal cognitive development. We identified a subset of five individuals who had been putatively diagnosed with "DA2A with severe neurological abnormalities" and for whom congenital contractures of the limbs and face, hypotonia, and global developmental delay had resulted in early death in three cases; this is a unique condition that we now refer to as CLIFAHDD syndrome. Exome sequencing identified missense mutations in the sodium leak channel, non-selective (NALCN) in four families affected by CLIFAHDD syndrome. We used molecular-inversion probes to screen for NALCN in a cohort of 202 distal arthrogryposis (DA)-affected individuals as well as concurrent exome sequencing of six other DA-affected individuals, thus revealing NALCN mutations in ten additional families with "atypical" forms of DA. All 14 mutations were missense variants predicted to alter amino acid residues in or near the S5 and S6 pore-forming segments of NALCN, highlighting the functional importance of these segments. In vitro functional studies demonstrated that NALCN alterations nearly abolished the expression of wild-type NALCN, suggesting that alterations that cause CLIFAHDD syndrome have a dominant-negative effect. In contrast, homozygosity for mutations in other regions of NALCN has been reported in three families affected by an autosomal-recessive condition characterized mainly by hypotonia and severe intellectual disability. Accordingly, mutations in NALCN can cause either a recessive or dominant condition characterized by varied though overlapping phenotypic features, perhaps based on the type of mutation and affected protein domain(s).

}, keywords = {Arthrogryposis, Contracture, Craniofacial Dysostosis, Cytoskeletal Proteins, Exome, Extremities, Face, Female, Gene Frequency, High-Throughput Nucleotide Sequencing, Homozygote, Humans, Infant, Male, Muscle Hypotonia, Mutation, Missense, Sodium Channels}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.01.003}, author = {Chong, Jessica X and McMillin, Margaret J and Shively, Kathryn M and Beck, Anita E and Marvin, Colby T and Armenteros, Jose R and Buckingham, Kati J and Nkinsi, Naomi T and Boyle, Evan A and Berry, Margaret N and Bocian, Maureen and Foulds, Nicola and Uzielli, Maria Luisa Giovannucci and Haldeman-Englert, Chad and Hennekam, Raoul C M and Kaplan, Paige and Kline, Antonie D and Mercer, Catherine L and Nowaczyk, Malgorzata J M and Klein Wassink-Ruiter, Jolien S and McPherson, Elizabeth W and Moreno, Regina A and Scheuerle, Angela E and Shashi, Vandana and Stevens, Cathy A and Carey, John C and Monteil, Arnaud and Lory, Philippe and Tabor, Holly K and Smith, Joshua D and Shendure, Jay and Nickerson, Deborah A and Bamshad, Michael J} } @article {227, title = {Exome sequencing identifies a recurrent de novo ZSWIM6 mutation associated with acromelic frontonasal dysostosis.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Aug 07}, pages = {235-40}, abstract = {

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

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

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

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

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

}, keywords = {Abnormalities, Multiple, Cell Cycle, Chromatin Assembly and Disassembly, DNA-Binding Proteins, Face, Female, Hand Deformities, Congenital, Haploinsufficiency, Humans, Intellectual Disability, Male, Micrognathism, Neck, Transcription Factors}, issn = {1750-1172}, doi = {10.1186/1750-1172-9-43}, author = {Sim, Joe C H and White, Susan M and Fitzpatrick, Elizabeth and Wilson, Gabrielle R and Gillies, Greta and Pope, Kate and Mountford, Hayley S and Torring, Pernille M and McKee, Shane and Vulto-van Silfhout, Anneke T and Jhangiani, Shalini N and Muzny, Donna M and Leventer, Richard J and Delatycki, Martin B and Amor, David J and Lockhart, Paul J} }