@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} }