title: Cosegregation of C-insertion at position 961 with the A1555G mutation of the mitochondrial 12S rRNA gene in a large Chinese family with maternally inherited hearing loss.
abstract: Mutations in the mitochondrial DNA have been shown to be one of the most important causes of sensorineural hearing loss. Here, we report the characterization of a large Chinese family (507 members in six generations) with maternally inherited non-syndromic hearing loss. Members of this family showed variable severity and age-of-onset of hearing impairment. In particular, the average age at onset of hearing loss in this family changed from 49 years (generation III) to 3 years (generation VI). Sequence analysis of the complete mitochondrial genome in this pedigree revealed the presence of a homoplasmic A1555G mutation in the 12S rRNA gene and other nucleotide changes. Of these changes, a C insertion at position 961 in the 12S rRNA gene is of special interest as mutations at this position have been found to be associated with aminoglycoside induced deafness in several genetically unrelated families. These data imply that the C insertion at position 961 in the 12S rRNA gene, acting as a secondary factor, could play a role in the phenotypic expression of the deafness associated A1555G mutation.
authors.affiliation: Division and Program in Human Genetics, Center for Hearing and Deafness Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Ronghua
authors.initials: R
authors.lastname: Li
authors.forename: Guangqian
authors.initials: G
authors.lastname: Xing
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.forename: Xing
authors.initials: X
authors.lastname: Cao
authors.forename: Xue-Zhong
authors.initials: XZ
authors.lastname: Liu
authors.forename: Xingkuan
authors.initials: X
authors.lastname: Bu
authors.forename: Min-Xin
authors.initials: MX
authors.lastname: Guan
mesh_terms: D017668:Age of Onset; D001483:Base Sequence; D002681:China; D003570:Cytidine Triphosphate / Q000235:genetics; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D005192:Family Health; D005260:Female; D034381:Hearing Loss / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D016254:Mutagenesis, Insertional; D010375:Pedigree; D017354:Point Mutation; D012335:RNA, Ribosomal / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; D003570:Cytidine Triphosphate