@article {135, title = {Exome Sequence Analysis Suggests that Genetic Burden Contributes to Phenotypic Variability and Complex Neuropathy.}, journal = {Cell Rep}, volume = {12}, year = {2015}, month = {2015 Aug 18}, pages = {1169-83}, abstract = {

Charcot-Marie-Tooth (CMT) disease is a clinically and genetically heterogeneous distal symmetric polyneuropathy. Whole-exome sequencing (WES) of 40 individuals from 37 unrelated families with CMT-like peripheral neuropathy refractory to molecular diagnosis identified apparent causal mutations in \~{} 45\% (17/37) of families. Three candidate disease genes are proposed, supported by a combination of genetic and in vivo studies. Aggregate analysis of mutation data revealed a significantly increased number of rare variants across 58 neuropathy-associated genes in subjects versus controls, confirmed in a second ethnically discrete neuropathy cohort, suggesting that mutation burden potentially contributes to phenotypic variability. Neuropathy genes shown to have highly penetrant Mendelizing variants (HPMVs) and implicated by burden in families were shown to interact genetically in a zebrafish assay exacerbating the phenotype established by the suppression of single genes. Our findings suggest that the combinatorial effect of rare variants contributes to disease burden and variable expressivity.

}, keywords = {Animals, Charcot-Marie-Tooth Disease, Exome, Female, Genetic Load, Genetic Variation, HSP40 Heat-Shock Proteins, Humans, Male, Mutation, Myelin P2 Protein, Pedigree, Penetrance, Peripheral Nervous System Diseases, Phenotype, Serine C-Palmitoyltransferase, Suppression, Genetic, Zebrafish}, issn = {2211-1247}, doi = {10.1016/j.celrep.2015.07.023}, author = {Gonzaga-Jauregui, Claudia and Harel, Tamar and Gambin, Tomasz and Kousi, Maria and Griffin, Laurie B and Francescatto, Ludmila and Ozes, Burcak and Karaca, Ender and Jhangiani, Shalini N and Bainbridge, Matthew N and Lawson, Kim S and Pehlivan, Davut and Okamoto, Yuji and Withers, Marjorie and Mancias, Pedro and Slavotinek, Anne and Reitnauer, Pamela J and Goksungur, Meryem T and Shy, Michael and Crawford, Thomas O and Koenig, Michel and Willer, Jason and Flores, Brittany N and Pediaditrakis, Igor and Us, Onder and Wiszniewski, Wojciech and Parman, Yesim and Antonellis, Anthony and Muzny, Donna M and Katsanis, Nicholas and Battaloglu, Esra and Boerwinkle, Eric and Gibbs, Richard A and Lupski, James R} } @article {220, title = {A drosophila genetic resource of mutants to study mechanisms underlying human genetic diseases.}, journal = {Cell}, volume = {159}, year = {2014}, month = {2014 Sep 25}, pages = {200-214}, abstract = {

Invertebrate model systems are powerful tools for studying human disease owing to their genetic tractability and ease of screening. We conducted a mosaic genetic screen of lethal mutations on the Drosophila X chromosome to identify genes required for the development, function, and maintenance of the nervous system. We identified 165 genes, most of whose function has not been studied in vivo. In parallel, we investigated rare variant alleles in 1,929 human exomes from families with unsolved Mendelian disease. Genes that are essential in flies and have multiple human homologs were found to be likely to be associated with human diseases. Merging the human data sets with the fly genes allowed us to identify disease-associated mutations in six families and to provide insights into microcephaly associated with brain dysgenesis. This bidirectional synergism between fly genetics and human genomics facilitates the functional annotation of evolutionarily conserved genes involved in human health.

}, keywords = {Animals, Disease, Disease Models, Animal, Drosophila melanogaster, Genetic Testing, Humans, Inheritance Patterns, RNA Interference, X Chromosome}, issn = {1097-4172}, doi = {10.1016/j.cell.2014.09.002}, author = {Yamamoto, Shinya and Jaiswal, Manish and Charng, Wu-Lin and Gambin, Tomasz and Karaca, Ender and Mirzaa, Ghayda and Wiszniewski, Wojciech and Sandoval, Hector and Haelterman, Nele A and Xiong, Bo and Zhang, Ke and Bayat, Vafa and David, Gabriela and Li, Tongchao and Chen, Kuchuan and Gala, Upasana and Harel, Tamar and Pehlivan, Davut and Penney, Samantha and Vissers, Lisenka E L M and de Ligt, Joep and Jhangiani, Shalini N and Xie, Yajing and Tsang, Stephen H and Parman, Yesim and Sivaci, Merve and Battaloglu, Esra and Muzny, Donna and Wan, Ying-Wooi and Liu, Zhandong and Lin-Moore, Alexander T and Clark, Robin D and Curry, Cynthia J and Link, Nichole and Schulze, Karen L and Boerwinkle, Eric and Dobyns, William B and Allikmets, Rando and Gibbs, Richard A and Chen, Rui and Lupski, James R and Wangler, Michael F and Bellen, Hugo J} } @article {285, title = {Exonic duplication CNV of NDRG1 associated with autosomal-recessive HMSN-Lom/CMT4D.}, journal = {Genet Med}, volume = {16}, year = {2014}, month = {2014 May}, pages = {386-394}, abstract = {

PURPOSE: Copy-number variations as a mutational mechanism contribute significantly to human disease. Approximately one-half of the patients with Charcot-Marie-Tooth (CMT) disease have a 1.4 Mb duplication copy-number variation as the cause of their neuropathy. However, non-CMT1A neuropathy patients rarely have causative copy-number variations, and to date, autosomal-recessive disease has not been associated with copy-number variation as a mutational mechanism.

METHODS: We performed Agilent 8 {\texttimes} 60 K array comparative genomic hybridization on DNA from 12 recessive Turkish families with CMT disease. Additional molecular studies were conducted to detect breakpoint junctions and to evaluate gene expression levels in a family in which we detected an intragenic duplication copy-number variation.

RESULTS: We detected an ~6.25 kb homozygous intragenic duplication in NDRG1, a gene known to be causative for recessive HMSNL/CMT4D, in three individuals from a Turkish family with CMT neuropathy. Further studies showed that this intragenic copy-number variation resulted in a homozygous duplication of exons 6-8 that caused decreased mRNA expression of NDRG1.

CONCLUSION: Exon-focused high-resolution array comparative genomic hybridization enables the detection of copy-number variation carrier states in recessive genes, particularly small copy-number variations encompassing or disrupting single genes. In families for whom a molecular diagnosis has not been elucidated by conventional clinical assays, an assessment for copy-number variations in known CMT genes might be considered.

}, keywords = {Adult, Base Sequence, Cell Cycle Proteins, Charcot-Marie-Tooth Disease, Comparative Genomic Hybridization, DNA Copy Number Variations, Female, Gene Duplication, Gene Expression, Genes, Recessive, Humans, Intracellular Signaling Peptides and Proteins, Male, Mutation, Refsum Disease, Sequence Analysis, DNA, Turkey, Young Adult}, issn = {1530-0366}, doi = {10.1038/gim.2013.155}, author = {Okamoto, Yuji and Goksungur, Meryem Tuba and Pehlivan, Davut and Beck, Christine R and Gonzaga-Jauregui, Claudia and Muzny, Donna M and Atik, Mehmed M and Carvalho, Claudia M B and Matur, Zeliha and Bayraktar, Serife and Boone, Philip M and Akyuz, Kaya and Gibbs, Richard A and Battaloglu, Esra and Parman, Yesim and Lupski, James R} }