@article {453, title = {High Rate of Recurrent De Novo Mutations in Developmental and Epileptic Encephalopathies.}, journal = {Am J Hum Genet}, volume = {101}, year = {2017}, month = {2017 Nov 02}, pages = {664-685}, abstract = {

Developmental and epileptic encephalopathy (DEE) is a group of conditions characterized by the co-occurrence of epilepsy and intellectual disability (ID), typically with developmental plateauing or regression associated with frequent epileptiform activity. The cause of DEE remains unknown in the majority of cases. We performed whole-genome sequencing (WGS) in 197 individuals with unexplained DEE and pharmaco-resistant seizures and in their unaffected parents. We focused our attention on de novo mutations (DNMs) and identified candidate genes containing such variants. We sought to identify additional subjects with DNMs in these genes by performing targeted sequencing in another series of individuals with DEE and by mining various sequencing datasets. We also performed meta-analyses to document enrichment of DNMs in candidate genes by leveraging our WGS dataset with those of several DEE and ID series. By combining these strategies, we were able to provide a causal link between DEE and the following genes: NTRK2, GABRB2, CLTC, DHDDS, NUS1, RAB11A, GABBR2, and SNAP25. Overall, we established a molecular diagnosis in 63/197 (32\%) individuals in our WGS series. The main cause of DEE in these individuals was de novo point mutations (53/63 solved cases), followed by inherited mutations (6/63 solved cases) and de novo CNVs (4/63 solved cases). De novo missense variants explained a larger proportion of individuals in our series than in other series that were primarily ascertained because of ID. Moreover, these DNMs were more frequently recurrent than those identified in ID series. These observations indicate that the genetic landscape of DEE might be different from that of ID without epilepsy.

}, keywords = {Brain Diseases, Child, Child, Preschool, Epilepsy, Female, Genome, Human, Genome-Wide Association Study, Humans, Intellectual Disability, Male, Mutation, Recurrence, Seizures}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.09.008}, author = {Hamdan, Fadi F and Myers, Candace T and Cossette, Patrick and Lemay, Philippe and Spiegelman, Dan and Laporte, Alexandre Dionne and Nassif, Christina and Diallo, Ousmane and Monlong, Jean and Cadieux-Dion, Maxime and Dobrzeniecka, Sylvia and Meloche, Caroline and Retterer, Kyle and Cho, Megan T and Rosenfeld, Jill A and Bi, Weimin and Massicotte, Christine and Miguet, Marguerite and Brunga, Ledia and Regan, Brigid M and Mo, Kelly and Tam, Cory and Schneider, Amy and Hollingsworth, Georgie and FitzPatrick, David R and Donaldson, Alan and Canham, Natalie and Blair, Edward and Kerr, Bronwyn and Fry, Andrew E and Thomas, Rhys H and Shelagh, Joss and Hurst, Jane A and Brittain, Helen and Blyth, Moira and Lebel, Robert Roger and Gerkes, Erica H and Davis-Keppen, Laura and Stein, Quinn and Chung, Wendy K and Dorison, Sara J and Benke, Paul J and Fassi, Emily and Corsten-Janssen, Nicole and Kamsteeg, Erik-Jan and Mau-Them, Frederic T and Bruel, Ange-Line and Verloes, Alain and {\~O}unap, Katrin and Wojcik, Monica H and Albert, Dara V F and Venkateswaran, Sunita and Ware, Tyson and Jones, Dean and Liu, Yu-Chi and Mohammad, Shekeeb S and Bizargity, Peyman and Bacino, Carlos A and Leuzzi, Vincenzo and Martinelli, Simone and Dallapiccola, Bruno and Tartaglia, Marco and Blumkin, Lubov and Wierenga, Klaas J and Purcarin, Gabriela and O{\textquoteright}Byrne, James J and Stockler, Sylvia and Lehman, Anna and Keren, Boris and Nougues, Marie-Christine and Mignot, Cyril and Auvin, St{\'e}phane and Nava, Caroline and Hiatt, Susan M and Bebin, Martina and Shao, Yunru and Scaglia, Fernando and Lalani, Seema R and Frye, Richard E and Jarjour, Imad T and Jacques, St{\'e}phanie and Boucher, Renee-Myriam and Riou, Emilie and Srour, Myriam and Carmant, Lionel and Lortie, Anne and Major, Philippe and Diadori, Paola and Dubeau, Fran{\c c}ois and D{\textquoteright}Anjou, Guy and Bourque, Guillaume and Berkovic, Samuel F and Sadleir, Lynette G and Campeau, Philippe M and Kibar, Zoha and Lafreni{\`e}re, Ronald G and Girard, Simon L and Mercimek-Mahmutoglu, Saadet and Boelman, Cyrus and Rouleau, Guy A and Scheffer, Ingrid E and Mefford, Heather C and Andrade, Danielle M and Rossignol, Elsa and Minassian, Berge A and Michaud, Jacques L} } @article {281, title = {The genetic basis of DOORS syndrome: an exome-sequencing study.}, journal = {Lancet Neurol}, volume = {13}, year = {2014}, month = {2014 Jan}, pages = {44-58}, abstract = {

BACKGROUND: Deafness, onychodystrophy, osteodystrophy, mental retardation, and seizures (DOORS) syndrome is a rare autosomal recessive disorder of unknown cause. We aimed to identify the genetic basis of this syndrome by sequencing most coding exons in affected individuals.

METHODS: Through a search of available case studies and communication with collaborators, we identified families that included at least one individual with at least three of the five main features of the DOORS syndrome: deafness, onychodystrophy, osteodystrophy, intellectual disability, and seizures. Participants were recruited from 26 centres in 17 countries. Families described in this study were enrolled between Dec 1, 2010, and March 1, 2013. Collaborating physicians enrolling participants obtained clinical information and DNA samples from the affected child and both parents if possible. We did whole-exome sequencing in affected individuals as they were enrolled, until we identified a candidate gene, and Sanger sequencing to confirm mutations. We did expression studies in human fibroblasts from one individual by real-time PCR and western blot analysis, and in mouse tissues by immunohistochemistry and real-time PCR.

FINDINGS: 26 families were included in the study. We did exome sequencing in the first 17 enrolled families; we screened for TBC1D24 by Sanger sequencing in subsequent families. We identified TBC1D24 mutations in 11 individuals from nine families (by exome sequencing in seven families, and Sanger sequencing in two families). 18 families had individuals with all five main features of DOORS syndrome, and TBC1D24 mutations were identified in half of these families. The seizure types in individuals with TBC1D24 mutations included generalised tonic-clonic, complex partial, focal clonic, and infantile spasms. Of the 18 individuals with DOORS syndrome from 17 families without TBC1D24 mutations, eight did not have seizures and three did not have deafness. In expression studies, some mutations abrogated TBC1D24 mRNA stability. We also detected Tbc1d24 expression in mouse phalangeal chondrocytes and calvaria, which suggests a role of TBC1D24 in skeletogenesis.

INTERPRETATION: Our findings suggest that mutations in TBC1D24 seem to be an important cause of DOORS syndrome and can cause diverse phenotypes. Thus, individuals with DOORS syndrome without deafness and seizures but with the other features should still be screened for TBC1D24 mutations. More information is needed to understand the cellular roles of TBC1D24 and identify the genes responsible for DOORS phenotypes in individuals who do not have a mutation in TBC1D24.

FUNDING: US National Institutes of Health, the CIHR (Canada), the NIHR (UK), the Wellcome Trust, the Henry Smith Charity, and Action Medical Research.

}, keywords = {Adolescent, Carrier Proteins, Child, Child, Preschool, Craniofacial Abnormalities, Exome, Female, Hand Deformities, Congenital, Hearing Loss, Sensorineural, Humans, Infant, Intellectual Disability, Internationality, Male, Nails, Malformed, Phenotype, Sequence Analysis, DNA, Young Adult}, issn = {1474-4465}, doi = {10.1016/S1474-4422(13)70265-5}, author = {Campeau, Philippe M and Kasperaviciute, Dalia and Lu, James T and Burrage, Lindsay C and Kim, Choel and Hori, Mutsuki and Powell, Berkley R and Stewart, Fiona and F{\'e}lix, T{\^e}mis Maria and van den Ende, Jenneke and Wisniewska, Marzena and Kayserili, H{\"u}lya and Rump, Patrick and Nampoothiri, Sheela and Aftimos, Salim and Mey, Antje and Nair, Lal D V and Begleiter, Michael L and De Bie, Isabelle and Meenakshi, Girish and Murray, Mitzi L and Repetto, Gabriela M and Golabi, Mahin and Blair, Edward and Male, Alison and Giuliano, Fabienne and Kariminejad, Ariana and Newman, William G and Bhaskar, Sanjeev S and Dickerson, Jonathan E and Kerr, Bronwyn and Banka, Siddharth and Giltay, Jacques C and Wieczorek, Dagmar and Tostevin, Anna and Wiszniewska, Joanna and Cheung, Sau Wai and Hennekam, Raoul C and Gibbs, Richard A and Lee, Brendan H and Sisodiya, Sanjay M} }