@article {9, title = {Identification of a RAI1-associated disease network through integration of exome sequencing, transcriptomics, and 3D genomics.}, journal = {Genome Med}, volume = {8}, year = {2016}, month = {2016 Nov 01}, pages = {105}, abstract = {

BACKGROUND: Smith-Magenis syndrome (SMS) is a developmental disability/multiple congenital anomaly disorder resulting from haploinsufficiency of RAI1. It is characterized by distinctive facial features, brachydactyly, sleep disturbances, and stereotypic behaviors.

METHODS: We investigated a cohort of 15 individuals with a clinical suspicion of SMS who showed neither deletion in the SMS critical region nor damaging variants in RAI1 using whole exome sequencing. A combination of network analysis (co-expression and biomedical text mining), transcriptomics, and circularized chromatin conformation capture (4C-seq) was applied to verify whether modified genes are part of the same disease network as known SMS-causing genes.

RESULTS: Potentially deleterious variants were identified in nine of these individuals using whole-exome sequencing. Eight of these changes affect KMT2D, ZEB2, MAP2K2, GLDC, CASK, MECP2, KDM5C, and POGZ, known to be associated with Kabuki syndrome 1, Mowat-Wilson syndrome, cardiofaciocutaneous syndrome, glycine encephalopathy, mental retardation and microcephaly with pontine and cerebellar hypoplasia, X-linked mental retardation 13, X-linked mental retardation Claes-Jensen type, and White-Sutton syndrome, respectively. The ninth individual carries a de novo variant in JAKMIP1, a regulator of neuronal translation that was recently found deleted in a patient with autism spectrum disorder. Analyses of co-expression and biomedical text mining suggest that these pathologies and SMS are part of the same disease network. Further support for this hypothesis was obtained from transcriptome profiling that showed that the expression levels of both Zeb2 and Map2k2 are perturbed in Rai1 mice. As an orthogonal approach to potentially contributory disease gene variants, we used chromatin conformation capture to reveal chromatin contacts between RAI1 and the loci flanking ZEB2 and GLDC, as well as between RAI1 and human orthologs of the genes that show perturbed expression in our Rai1 mouse model.

CONCLUSIONS: These holistic studies of RAI1 and its interactions allow insights into SMS and other disorders associated with intellectual disability and behavioral abnormalities. Our findings support a pan-genomic approach to the molecular diagnosis of a distinctive disorder.

}, keywords = {Animals, Embryo, Mammalian, Exome, Female, Gene Regulatory Networks, Genomics, Humans, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Mutation, Phenotype, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, RNA, Messenger, Smith-Magenis Syndrome, Trans-Activators, Transcription Factors, Transcriptome}, issn = {1756-994X}, doi = {10.1186/s13073-016-0359-z}, author = {Loviglio, Maria Nicla and Beck, Christine R and White, Janson J and Leleu, Marion and Harel, Tamar and Guex, Nicolas and Niknejad, Anne and Bi, Weimin and Chen, Edward S and Crespo, Isaac and Yan, Jiong and Charng, Wu-Lin and Gu, Shen and Fang, Ping and Coban-Akdemir, Zeynep and Shaw, Chad A and Jhangiani, Shalini N and Muzny, Donna M and Gibbs, Richard A and Rougemont, Jacques and Xenarios, Ioannis and Lupski, James R and Reymond, Alexandre} } @article {122, title = {Allelic Mutations of KITLG, Encoding KIT Ligand, Cause Asymmetric and Unilateral Hearing Loss and Waardenburg Syndrome Type 2.}, journal = {Am J Hum Genet}, volume = {97}, year = {2015}, month = {2015 Nov 05}, pages = {647-60}, abstract = {

Linkage analysis combined with whole-exome sequencing in a large family with congenital and stable non-syndromic unilateral and asymmetric hearing loss (NS-UHL/AHL) revealed a heterozygous truncating mutation, c.286_303delinsT (p.Ser96Ter), in KITLG. This mutation co-segregated with NS-UHL/AHL as a dominant trait with reduced penetrance. By screening a panel of probands with NS-UHL/AHL, we found an additional mutation, c.200_202del (p.His67_Cys68delinsArg). In~vitro studies revealed that the p.His67_Cys68delinsArg transmembrane isoform of KITLG is not detectable at the cell membrane, supporting pathogenicity. KITLG encodes a ligand for the KIT receptor. Also, KITLG-KIT signaling and MITF are suggested to mutually interact in melanocyte development. Because mutations in MITF are causative of Waardenburg syndrome type 2 (WS2), we screened KITLG in suspected WS2-affected probands. A heterozygous missense mutation, c.310C>G (p.Leu104Val), that segregated with WS2 was identified in a small family. In~vitro studies revealed that the p.Leu104Val transmembrane isoform of KITLG is located at the cell membrane, as is wild-type KITLG. However, in culture media of transfected cells, the p.Leu104Val soluble isoform of KITLG was reduced, and no soluble p.His67_Cys68delinsArg and p.Ser96Ter KITLG could be detected. These data suggest that mutations in KITLG associated with NS-UHL/AHL have a loss-of-function effect. We speculate that the mechanism of the mutation underlying WS2 and leading to membrane incorporation and reduced secretion of KITLG occurs via a dominant-negative or gain-of-function effect. Our study unveils different phenotypes associated with KITLG, previously associated with pigmentation abnormalities, and will thereby improve the genetic counseling given to individuals with KITLG variants.

}, keywords = {Alleles, Animals, Female, Fluorescent Antibody Technique, Genetic Linkage, Hearing Loss, Unilateral, Humans, Male, Mice, Mutation, NIH 3T3 Cells, Pedigree, Phenotype, Prognosis, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, RNA, Messenger, Stem Cell Factor, Waardenburg Syndrome}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.09.011}, author = {Zazo Seco, Celia and Serr{\~a}o de Castro, Luciana and van Nierop, Josephine W and Mor{\'\i}n, Mat{\'\i}as and Jhangiani, Shalini and Verver, Eva J J and Schraders, Margit and Maiwald, Nadine and Wesdorp, Mieke and Venselaar, Hanka and Spruijt, Liesbeth and Oostrik, Jaap and Schoots, Jeroen and van Reeuwijk, Jeroen and Lelieveld, Stefan H and Huygen, Patrick L M and Insenser, Mar{\'\i}a and Admiraal, Ronald J C and Pennings, Ronald J E and Hoefsloot, Lies H and Arias-V{\'a}squez, Alejandro and de Ligt, Joep and Yntema, Helger G and Jansen, Joop H and Muzny, Donna M and Huls, Gerwin and van Rossum, Michelle M and Lupski, James R and Moreno-Pelayo, Miguel Angel and Kunst, Henricus P M and Kremer, Hannie} } @article {261, title = {Mutations in Alstr{\"o}m protein impair terminal differentiation of cardiomyocytes.}, journal = {Nat Commun}, volume = {5}, year = {2014}, month = {2014 Mar 04}, pages = {3416}, abstract = {

Cardiomyocyte cell division and replication in mammals proceed through embryonic development and abruptly decline soon after birth. The process governing cardiomyocyte cell cycle arrest is poorly understood. Here we carry out whole-exome sequencing in an infant with evidence of persistent postnatal cardiomyocyte replication to determine the genetic risk factors. We identify compound heterozygous ALMS1 mutations in the proband, and confirm their presence in her affected sibling, one copy inherited from each heterozygous parent. Next, we recognize homozygous or compound heterozygous truncating mutations in ALMS1 in four other children with high levels of postnatal cardiomyocyte proliferation. Alms1 mRNA knockdown increases multiple markers of proliferation in cardiomyocytes, the percentage of cardiomyocytes in G2/M phases, and the number of cardiomyocytes by 10\% in cultured cells. Homozygous Alms1-mutant mice have increased cardiomyocyte proliferation at 2 weeks postnatal compared with wild-type littermates. We conclude that deficiency of Alstr{\"o}m protein impairs postnatal cardiomyocyte cell cycle arrest.

}, keywords = {Animals, Cell Cycle, Cell Differentiation, Cells, Cultured, DNA-Binding Proteins, Humans, Immunohistochemistry, Mice, Molecular Sequence Data, Mutation, Myocytes, Cardiac, Proteins, Reverse Transcriptase Polymerase Chain Reaction}, issn = {2041-1723}, doi = {10.1038/ncomms4416}, author = {Shenje, Lincoln T and Andersen, Peter and Halushka, Marc K and Lui, Cecillia and Fernandez, Laviel and Collin, Gayle B and Amat-Alarcon, Nuria and Meschino, Wendy and Cutz, Ernest and Chang, Kenneth and Yonescu, Raluca and Batista, Denise A S and Chen, Yan and Chelko, Stephen and Crosson, Jane E and Scheel, Janet and Vricella, Luca and Craig, Brian D and Marosy, Beth A and Mohr, David W and Hetrick, Kurt N and Romm, Jane M and Scott, Alan F and Valle, David and Naggert, J{\"u}rgen K and Kwon, Chulan and Doheny, Kimberly F and Judge, Daniel P} }