title: Role of the mitochondrial mutations, m.827A>G and the novel m.7462C>T, in the origin of hearing loss.
abstract: Samples from 30 deaf probands exhibiting features suggestive of syndromic mitochondrial deafness or from families with maternal transmission of deafness were selected for investigation of mutations in the mitochondrial genes MT-RNR1 and MT-TS1. Patients with mutation m.1555A>G had been previously excluded from this sample. In the MT-RNR1 gene, five probands presented the m.827A>G sequence variant, of uncertain pathogenicity. This change was also detected in 66 subjects of an unaffected control sample of 306 Brazilian individuals from various ethnic backgrounds. Given its high frequency, we consider it unlikely to have a pathogenic role on hereditary deafness. As to the MT-TS1 gene, one proband presented the previously known pathogenic m.7472insC mutation and three probands presented a novel variant, m.7462C>T, which was absent from the same control sample of 306 individuals. Because of its absence in control samples and association with a family history of hearing impairment, we suggest it might be a novel pathogenic mutation.
authors: Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, Brazil.
authors: Daniela Tiaki
authors: DT
authors: Uehara
authors: Daniel
authors: D
authors: Rincon
authors: Ronaldo Serafim
authors: RS
authors: Abreu-Silva
authors: Maria Teresa Balester de Mello
authors: MT
authors: Auricchio
authors: Alfredo
authors: A
authors: Tabith
authors: Fernando
authors: F
authors: Kok
authors: Regina Célia
authors: RC
authors: Mingroni-Netto
mesh_terms: D001938:Brazil / Q000453:epidemiology; D004272:DNA, Mitochondrial / Q000235:genetics*; D003638:Deafness / Q000208:ethnology / Q000235:genetics*; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D050259:Genes, Mitochondrial; D006239:Haplotypes / Q000235:genetics; D006319:Hearing Loss, Sensorineural / Q000208:ethnology / Q000235:genetics*; D006801:Humans; D008297:Male; D010375:Pedigree; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012335:RNA, Ribosomal / Q000235:genetics* / Q000502:physiology; D012362:RNA, Transfer, Ser / Q000235:genetics* / Q000502:physiology
chemical_list: D004272:DNA, Mitochondrial; D012335:RNA, Ribosomal; D012362:RNA, Transfer, Ser; C075526:RNA, ribosomal, 12S