TMEM240 mutations cause spinocerebellar ataxia 21 with mental retardation and severe cognitive impairment.
Brain
; 137(Pt 10): 2657-63, 2014 Oct.
Article
em En
| MEDLINE
| ID: mdl-25070513
ABSTRACT
Autosomal dominant cerebellar ataxia corresponds to a clinically and genetically heterogeneous group of neurodegenerative disorders that primarily affect the cerebellum. Here, we report the identification of the causative gene in spinocerebellar ataxia 21, an autosomal-dominant disorder previously mapped to chromosome 7p21.3-p15.1. This ataxia was firstly characterized in a large French family with slowly progressive cerebellar ataxia, accompanied by severe cognitive impairment and mental retardation in two young children. Following the recruitment of 12 additional young family members, linkage analysis enabled us to definitively map the disease locus to chromosome 1p36.33-p36.32. The causative mutation, (c.509C>T/p.P170L) in the transmembrane protein gene TMEM240, was identified by whole exome sequencing and then was confirmed by Sanger sequencing and co-segregation analyses. Index cases from 368 French families with autosomal-dominant cerebellar ataxia were also screened for mutations. In seven cases, we identified a range of missense mutations (c.509C>T/p.P170L, c.239C>T/p.T80M, c.346C>T/p.R116C, c.445G>A/p.E149K, c.511C>T/p.R171W), and a stop mutation (c.489C>G/p.Y163*) in the same gene. TMEM240 is a small, strongly conserved transmembrane protein of unknown function present in cerebellum and brain. Spinocerebellar ataxia 21 may be a particular early-onset disease associated with severe cognitive impairment.
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Base de dados:
MEDLINE
Assunto principal:
Degenerações Espinocerebelares
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Transtornos Cognitivos
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Proteínas de Membrana
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Deficiência Intelectual
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Mutação
Tipo de estudo:
Etiology_studies
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Incidence_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Child
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Child, preschool
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Female
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Humans
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Infant
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Male
País como assunto:
Europa
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article