title: mtDNA mutation C1494T, haplogroup A, and hearing loss in Chinese.
abstract: Mutation C1494T in mitochondrial 12S rRNA gene was recently reported in two large Chinese families with aminoglycoside-induced and nonsyndromic hearing loss (AINHL) and was claimed to be pathogenic. This mutation, however, was first reported in a sample from central China in our previous study that was aimed to reconstruct East Asian mtDNA phylogeny. All these three mtDNAs formed a subclade defined by mutation C1494T in mtDNA haplogroup A. It thus seems that mutation C1494T is a haplogroup A-associated mutation and this matrilineal background may contribute a high risk for the penetrance of mutation C1494T in Chinese with AINHL. To test this hypothesis, we first genotyped mutation C1494T in 553 unrelated individuals from three regional Chinese populations and performed an extensive search for published complete or near-complete mtDNA data sets (>3000 mtDNAs), we then screened the C1494T mutation in 111 mtDNAs with haplogroup A status that were identified from 1823 subjects across China. The search for published mtDNA data sets revealed no other mtDNA besides the above-mentioned three carrying mutation C1494T. None of the 553 randomly selected individuals and the 111 haplogroup A mtDNAs was found to bear this mutation. Therefore, our results suggest that C1494T is a very rare event. The mtDNA haplogroup A background in general is unlikely to play an active role in the penetrance of mutation C1494T in AINHL.
authors.affiliation: Laboratory of Cellular and Molecular Evolution, and Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
authors.forename: Cheng-Ye
authors.initials: CY
authors.lastname: Wang
authors.forename: Qing-Peng
authors.initials: QP
authors.lastname: Kong
authors.forename: Yong-Gang
authors.initials: YG
authors.lastname: Yao
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Zhang
mesh_terms: D000617:Aminoglycosides / Q000009:adverse effects; D044466:Asian People / Q000235:genetics; D002681:China; D004272:DNA, Mitochondrial / Q000235:genetics*; D034381:Hearing Loss / Q000139:chemically induced / Q000235:genetics*; D006801:Humans; D010802:Phylogeny; D017354:Point Mutation / Q000235:genetics*; D012335:RNA, Ribosomal / Q000235:genetics*
chemical_list: D000617:Aminoglycosides; D004272:DNA, Mitochondrial; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S