Mutations in the mitochondrial DNA have been certified to be one of the most important causes of maternally inherited sensorineural hearing loss. Among these, mitochondrial 12S rRNA1555A>G, 1494C>T and other mutations are associated with both nonsyndromic and drug induced hearing loss caused by aminoglycosides. Individuals carrying 1555A>G or 1494C>T mutation have a variety of clinical manifestations, which implies that the 1555A>G or 1494C>T mutation is a chief factor underlying the development of deafness but insufficient to produce the clinical phenotype. Therefore other modifier factors, such as aminoglycosides, mitochondrial haplotypes, secondary mutation or nuclear modifier genes, may play an important role in the phenotypic expression of the deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutation. In this review, the modifier factors for the phenotypic expression of deafness-associated mitochondrial 12S rRNA1555A>G or 1494C>T mutations were summarized and proposed the pathogenesis of maternally inherited deafness.
线粒体DNA(mitochondrial DNA，mtDNA)突变是导致母系遗传性非综合征型聋的重要原因之一。其中线粒体12S rRNA1555A>G、1494C>T等突变与非综合征型聋和氨基糖苷类抗生素导致的药物性聋有关。但携带1555A>G或1494C>T突变的个体临床表现具有多样性，提示线粒体12S rRNA1555A>G或1494C>T突变可能是导致母系遗传性聋发生的首要因子，其他的修饰因子如氨基糖苷类抗生素、线粒体单体型、线粒体继发突变和核基因等，在线粒体12S rRNA1555A>G或1494C>T突变相关的耳聋表型表达上起修饰作用。本综述将简要介绍这些因素对线粒体12S rRNA1555A>G或1494C>T突变致聋的影响及可能的致病机制。.
Keywords: Aminoglycosides; Deafness; Genes; Mitochondrial; Mutations.