非综合征性耳聋-家系分子病因学分析

Molecular etiology of non-syndromic hearing impairment in a Chinese family

目的从分子病因学角度分析一具有母系遗传特性的非综合征性耳聋家系耳聋原因。方法对该家系成员进行线粒体基因全序列及缝隙连接蛋白26编码基因（GJB2）全序列分析。结果接受检测的该家系先证者（Ⅲ-5）及另一母系成员（Ⅲ-1）均携带线粒体DNA12SrRNAC1494T突变；先证者聋前有氨基糖苷类抗生素应用史，表现为双侧重度感音神经性耳聋，携带线粒体DNA12SrRNAC1494T突变的另一母系成员（Ⅲ-1）聋前无氨基糖苷类抗生素应用史，表现为双侧中度感音神经性耳聋。GJB2基因检测未发现致病突变。结论线粒体DNA12SrRNAC1494T突变是氨基糖苷类抗生素致聋的原因之一，该突变致聋程度的不一致性可能与个体遗传背景不同有关。

Objective To investigate the molecular etiology of non-syndromic hearing impairment in two patients in a maternal inherited deafness Chinese family. Methods Peripheral blood specimens were collected and DNA templates extracted. The complete mitochondrial genomes and GJB2 gene were sequenced in an ABI 3100 Avant sequencer. Results The proband （ Ⅲ-5 ） and her elder sister（ Ⅲ-1 ） were found to carry the mtDNA 12SrRNA C1494T mutation. The GJB2 gcne showed no mutations. The proband had the history of using aminoglycosides before hearing loss, and exhibited severe sensorineural hearing impairment; the proband＇s sister had no history of using aminoglycosides, and showed moderate sensorineural hearing impairment. Conclusion The molecular etiology of each individual patient in a family yaries with individual genetic background.