摘要
目的 研究线粒体rRNA基因突变与氨基糖甙类抗生素致聋遗传易感性的关系,为建立相应的基因诊断方法提供依据。方法 收集了五个有明确氨基糖甙类抗生素应用史的耳聋家系共27名成员的外周静脉血标本,从白细胞中提取DNA,PCR扩增线粒体DNA片段,Alw26I限制性内切酶分析和DNA序列分析检测A1555G点突变,并对其中一个家系进行了线粒体DNA12S和16S rRNA基因的全序列分析。结果 家系A、C、D和E的21份样品均为A1555G点突变阳性,家系B的6份样品为 A1555G点突变阴性。家系 B线粒体DNA12S和16SrRNA基因全序列分析显示该家系存在16S rRNA基因第2227位“AA”插入突变。结论 本研究发现了一个A1555G点突变阴性的氨基糖甙类抗生素致聋家系,说明线粒体DNA A1555G点突变不是氨基糖甙类抗生素遗传易感性唯一的分子基础,对氨基糖甙类抗生素致聋遗传易感性的预测仅检测A1555G点突变是不够的,应与mtDNA其它相关突变位点的检测结合起来。
Objective It has been reported that familial aminoglycoside-induced deafness is mitochondrialinheritance and is associated with a homoplasmic A to G mutation at nucleotide 1555 in the mitochondrial 12Sribosomal RNA gene. However, it is not clear whether the A1555G mutation is the sole pathogenicmitochondrial DNA mutation associated with aminoglycoside-induced deafness. The aim of the present studyis to search and locate other possible mutations which may also be involved in this disease. MethodsTwenty-seven blood samples were obtained from five families with aminoglycoside-induced deafness forscreening the A1555G mutation. Results Alw26 I digestion of PCR products showed that twenty-one samplesfrom four families carried homoplasmic A1555G mutation, but six samples from one family did not have the1555G mutation. Mitochondrial 12S and 16S ribosomal RNA genes were amplified by PCR from two patientsof the family without 1555G mutation and were sequenced thoroughly to find novel DNA mutations associatedwith aminoglycoside-induced deafness. Both patients shared two bases of AA insertion at nucleotide 2227 in16S ribosomal RNA gene. Conclusion Our finding implies that the A1555G mutation is not the sole pathogenicmutation in aminoglycoside-induced deafness. Further studies will be done to determine whether 2227AAinsertion is a pathogenic mutation or a benign sequence variation and to investigate the functional effect ofthis putative mutation.
出处
《中国听力语言康复科学杂志》
2004年第6期10-14,共5页
Chinese Scientific Journal of Hearing and Speech Rehabilitation
基金
国家自然科学基金资助
批准号398000160
