近亲结婚所致非综合征型耳聋家系的线粒体基因突变分析

目的对一个呈母系遗传的非综合征型耳聋大家系进行线粒体DNA的突变检测。方法收集湖南省一个非综合征型遗传性耳聋家系成员外周静脉血，提取基因组DNA（含线粒体DNA），设计特异性引物对目的片段进行PCR扩增，直接测序检测突变类型。结果测序结果显示，线粒体12S rRNA基因A1555G突变为该家系的致病突变，非母系成员不存在这一突变。结论该家系中部分成员使用氨基糖甙类抗生素后出现耳聋，可能是因为药物与线粒体12S rRNA基因的A1555G突变共同参与了听力损伤过程。

Mutation analysis of 12S rRNA and tRNA-Ser(UCN) genes in a large Chinese family with maternally inherited nonsyndromic hearing loss by intermarriage

Objective To identify the possible mutation at possible sites in different mitochondrial genes that leads to hearing loss in a large Chinese pedigree. Methods Blood samples from a Hunan pedigree were obtained with informed consent. Genomic DNA was extracted from peripheral blood leukocytes using kit. The target fragments were amplified and detected by polymerase chain reaction (PCR) and directly sequencing respectively. Results The result of direct sequencing revealed the A1555G mutation in 12S rRNA gene was inherited in this pedigree and no one has A7445G mutation or other mutations in its neighborhood region. Conclusion Sequence analysis confirmed that the pedigree carries the A1555G mutation. With some members ever exposure of aminoglycoside antibiotics, mutation of A1555G may play a pivotal role in the pathogenesis of hearing loss in the large pedigree.