title: Low significance of MECP2 mutations as a cause of mental retardation in Brazilian males.
abstract: MeCP2 is a protein that selectively binds to methylated cytosines through its methyl-CpG-binding domain (MBD) and connects DNA methylation to transcriptional repression. Mutations in MECP2 gene, located in Xq28, have been reported as being the major cause of Rett syndrome and are also associated with some cases of X-linked mental retardation in both males and females. In this study, we present the first screening in the MECP2 gene in a Brazilian cohort of 239 unrelated males with idiopathic mental retardation. Eight sequence variations were observed in 10 patients: one novel putative pathogenic variant, two never described variants of unknown pathogenic value and five non-pathogenic variations. We conclude that in mentally retarded Brazilian males, non-pathogenic variants in the MECP2 gene are more common than actual pathogenic mutations, and therefore alterations in this gene have a weak relationship with mental retardation in males.
authors.affiliation: Human Genetics Service, Department of Cell Biology and Genetics, State University of Rio de Janeiro, Rua São Francisco Xavier 524, Maracanã, Rio de Janeiro 20550-013, Brazil.
authors.forename: Mário
authors.initials: M
authors.lastname: Campos
authors.forename: Cláudia Bueno
authors.initials: CB
authors.lastname: Abdalla
authors.forename: Cíntia Barros
authors.initials: CB
authors.lastname: Santos-Rebouças
authors.forename: Adriana Vaz
authors.initials: AV
authors.lastname: dos Santos
authors.forename: Cristiane Pinheiro
authors.initials: CP
authors.lastname: Pestana
authors.forename: Mariana Lopes
authors.initials: ML
authors.lastname: Domingues
authors.forename: Jussara Mendonça
authors.initials: JM
authors.lastname: dos Santos
authors.forename: Márcia Mattos Gonçalves
authors.initials: MM
authors.lastname: Pimentel
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003072:Cognition Disorders / Q000235:genetics / Q000523:psychology; D015331:Cohort Studies; D004247:DNA / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology; D007438:Introns / Q000235:genetics; D008297:Male; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D020125:Mutation, Missense / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2; D004247:DNA