12个非综合征型遗传性耳聋家系mtDNA12SrRNA,tRNA^(Leu(UUR)),tRNA^(Ser(UCN))及16SrRNA基因序列分析

Sequence analysis of mtDNA 12S rRNA, tRNA^(Leu(UUR)),tRNA^(Ser(UCN)) and 16S rRNA gene of 12 nonsyndromic inherited deafness pedigrees *

目的 探讨 mt DNA突变与遗传性耳聋的关系 ,以及突变家系对氨基糖甙类抗生素(aminoglycoside antibiotic,Am An)耳毒敏感性差异的原因。方法 调查了 12个非综合征型耳聋家系 ;抽取外周血 ,提取 DNA;PCR扩增线粒体 DNA(mitochondrial DNA,mt DNA)目的片段 ,分别以 Alw2 6 、Apa 及 Xba 限制性内切酶检测 15 5 5 G、32 43G及 744 5 G 点突变 ;行 mt DNA 12 S r RNA、t RNALeu(UUR) 、t RNASer(UCN)及 16 S r RNA基因序列测定。结果 经酶切及测序证实 12个家系具有 mt DNA突变 ,形式为 :15 5 5 G突变家系 10个 ,744 5 G突变家系 2个 ,未发现 32 43G 突变家系。基因测序显示 mt DNA 16 S r RNA基因序列变化形式为 :2 2 30 G点突变、2 2 30 AG插入、2 2 43AG插入及 2 2 30 AA插入突变 ,它们在家族性 Am An耳毒敏感性家系中被发现 ,且呈母系遗传 ;在 Am An不敏感家系中未被发现。结论 单纯 15 5 5 G或 744 5 G突变家系表现为无诱因的渐进性遗传性耳聋或先天性聋 ;15 5 5 G或 744 5 G突变合并 16 S r RNA基因突变者对Am An高度敏感 ,表现为家族性敏感致聋。

Objective To detect the relationship of mtDNA mutation with inherited deafness and the reason for pedigree's hypersensitivity to ototoxicity of aminoglycoside antibiotics(AmAn).Methods Pedigree investigations were conducted. The blood samples were obtained from 12 pedigrees, and DNA was extracted from the isolated leukocytes. After that, mtDNA fragments were amplified by PCR. The 1555 G, 3243 G and 7445 G mutations were detected by Alw 26 Ⅰ, Apa Ⅰ and Xba Ⅰ restriction endonuclease digestion respectively, and then sequencing of 12S rRNA, tRNA Leu(UUR), tRNA Ser(UCN) and 16S rRNA gene was performed. Results Restriction endonuclease digestion and sequence analysis showed that all the pedigrees carried mtDNA mutation, among them, 10 pedigrees carried 1555 G mutation; 2 pedigrees, 7445 G mutation; no pedigree was found to harbor the 3243 G mutation. Sequence analysis of 16S rRNA gene showed that the mutations are 2230 G, 2230 AG, 2243 AG, 2230 AA.Conclusion The pedigrees that carried 1555 G or 7445 G mutation showed hereditary or congenital hearing loss. The 1555 G or 7445 G mutation in association with 16S rRNA gene mutation led to pedigree's hypersensitivity to AmAn ototoxicity.