@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 {134, title = {Expanding the Molecular and Clinical Phenotype of SSR4-CDG.}, journal = {Hum Mutat}, volume = {36}, year = {2015}, month = {2015 Nov}, pages = {1048-51}, abstract = {

Congenital disorders of glycosylation (CDG) are a group of mostly autosomal recessive disorders primarily characterized by neurological abnormalities. Recently, we described a single CDG patient with a de novo mutation in the X-linked gene, Signal Sequence Receptor 4 (SSR4). We performed whole-exome sequencing to identify causal variants in several affected individuals who had either an undifferentiated neurological disorder or unsolved CDG of unknown etiology based on abnormal transferrin glycosylation. We now report eight affected males with either de novo (4) or inherited (4) loss of function mutations in SSR4. Western blot analysis revealed that the mutations caused a complete loss of SSR4 protein. In nearly all cases, the abnormal glycosylation of serum transferrin was only slightly above the accepted normal cutoff range.

}, keywords = {Calcium-Binding Proteins, Congenital Disorders of Glycosylation, DNA Mutational Analysis, Exome, Gene Order, Genes, X-Linked, Genetic Loci, Humans, Male, Membrane Glycoproteins, Mutation, Phenotype, Receptors, Cytoplasmic and Nuclear, Receptors, Peptide}, issn = {1098-1004}, doi = {10.1002/humu.22856}, author = {Ng, Bobby G and Raymond, Kimiyo and Kircher, Martin and Buckingham, Kati J and Wood, Tim and Shendure, Jay and Nickerson, Deborah A and Bamshad, Michael J and Wong, Jonathan T S and Monteiro, Fabiola Paoli and Graham, Brett H and Jackson, Sheryl and Sparkes, Rebecca and Scheuerle, Angela E and Cathey, Sara and Kok, Fernando and Gibson, James B and Freeze, Hudson H} } @article {248, title = {De novo truncating mutations in AHDC1 in individuals with syndromic expressive language delay, hypotonia, and sleep apnea.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 May 01}, pages = {784-9}, abstract = {

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

}, keywords = {Child, Child, Preschool, DNA-Binding Proteins, Exome, Female, Humans, Infant, Intellectual Disability, Language Development Disorders, Male, Muscle Hypotonia, Mutation, Sleep Apnea Syndromes, Syndrome}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.04.006}, author = {Xia, Fan and Bainbridge, Matthew N and Tan, Tiong Yang and Wangler, Michael F and Scheuerle, Angela E and Zackai, Elaine H and Harr, Margaret H and Sutton, V Reid and Nalam, Roopa L and Zhu, Wenmiao and Nash, Margot and Ryan, Monique M and Yaplito-Lee, Joy and Hunter, Jill V and Deardorff, Matthew A and Penney, Samantha J and Beaudet, Arthur L and Plon, Sharon E and Boerwinkle, Eric A and Lupski, James R and Eng, Christine M and Muzny, Donna M and Yang, Yaping and Gibbs, Richard A} } @article {273, title = {Loss-of-function HDAC8 mutations cause a phenotypic spectrum of Cornelia de Lange syndrome-like features, ocular hypertelorism, large fontanelle and X-linked inheritance.}, journal = {Hum Mol Genet}, volume = {23}, year = {2014}, month = {2014 Jun 01}, pages = {2888-900}, abstract = {

Cornelia de Lange syndrome (CdLS) is a multisystem genetic disorder with distinct facies, growth failure, intellectual disability, distal limb anomalies, gastrointestinal and neurological disease. Mutations in NIPBL, encoding a cohesin regulatory protein, account for >80\% of cases with typical facies. Mutations in the core cohesin complex proteins, encoded by the SMC1A, SMC3 and RAD21 genes, together account for \~{}5\% of subjects, often with atypical CdLS features. Recently, we identified mutations in the X-linked gene HDAC8 as the cause of a small number of CdLS cases. Here, we report a cohort of 38 individuals with an emerging spectrum of features caused by HDAC8 mutations. For several individuals, the diagnosis of CdLS was not considered prior to genomic testing. Most mutations identified are missense and de novo. Many cases are heterozygous females, each with marked skewing of X-inactivation in peripheral blood DNA. We also identified eight hemizygous males who are more severely affected. The craniofacial appearance caused by HDAC8 mutations overlaps that of typical CdLS but often displays delayed anterior fontanelle closure, ocular hypertelorism, hooding of the eyelids, a broader nose and dental anomalies, which may be useful discriminating features. HDAC8 encodes the lysine deacetylase for the cohesin subunit SMC3 and analysis of the functional consequences of the missense mutations indicates that all cause a loss of enzymatic function. These data demonstrate that loss-of-function mutations in HDAC8 cause a range of overlapping human developmental phenotypes, including a phenotypically distinct subgroup of CdLS.

}, keywords = {Amino Acid Sequence, Child, Child, Preschool, Cohort Studies, Cranial Fontanelles, De Lange Syndrome, Eye Abnormalities, Female, Genes, X-Linked, Histone Deacetylases, Humans, Hypertelorism, Infant, Male, Molecular Sequence Data, Mutation, Missense, Phenotype, Repressor Proteins, Sequence Alignment}, issn = {1460-2083}, doi = {10.1093/hmg/ddu002}, author = {Kaiser, Frank J and Ansari, Morad and Braunholz, Diana and Concepci{\'o}n Gil-Rodr{\'\i}guez, Mar{\'\i}a and Decroos, Christophe and Wilde, Jonathan J and Fincher, Christopher T and Kaur, Maninder and Bando, Masashige and Amor, David J and Atwal, Paldeep S and Bahlo, Melanie and Bowman, Christine M and Bradley, Jacquelyn J and Brunner, Han G and Clark, Dinah and Del Campo, Miguel and Di Donato, Nataliya and Diakumis, Peter and Dubbs, Holly and Dyment, David A and Eckhold, Juliane and Ernst, Sarah and Ferreira, Jose C and Francey, Lauren J and Gehlken, Ulrike and Guill{\'e}n-Navarro, Encarna and Gyftodimou, Yolanda and Hall, Bryan D and Hennekam, Raoul and Hudgins, Louanne and Hullings, Melanie and Hunter, Jennifer M and Yntema, Helger and Innes, A Micheil and Kline, Antonie D and Krumina, Zita and Lee, Hane and Leppig, Kathleen and Lynch, Sally Ann and Mallozzi, Mark B and Mannini, Linda and McKee, Shane and Mehta, Sarju G and Micule, Ieva and Mohammed, Shehla and Moran, Ellen and Mortier, Geert R and Moser, Joe-Ann S and Noon, Sarah E and Nozaki, Naohito and Nunes, Luis and Pappas, John G and Penney, Lynette S and P{\'e}rez-Ayt{\'e}s, Antonio and Petersen, Michael B and Puisac, Beatriz and Revencu, Nicole and Roeder, Elizabeth and Saitta, Sulagna and Scheuerle, Angela E and Schindeler, Karen L and Siu, Victoria M and Stark, Zornitza and Strom, Samuel P and Thiese, Heidi and Vater, Inga and Willems, Patrick and Williamson, Kathleen and Wilson, Louise C and Hakonarson, Hakon and Quintero-Rivera, Fabiola and Wierzba, Jolanta and Musio, Antonio and Gillessen-Kaesbach, Gabriele and Ramos, Feliciano J and Jackson, Laird G and Shirahige, Katsuhiko and Pi{\'e}, Juan and Christianson, David W and Krantz, Ian D and FitzPatrick, David R and Deardorff, Matthew A} }