摘要
目的探讨线粒体DNA(mitochondrialDNA,mtDNA)12SrRNA基因与中国人非综合征型遗传性耳聋的关系。方法对两个母系遗传性的非综合征型耳聋家系中20名成员及32例散发耳聋患者外周血DNA进行12SrRNA、tRNAser(UCN)以及GJB2基因PCR扩增,产物通过限制性片段多态性分析及基因测序,进行突变检测和分析。结果所有研究对象的基因区域均扩增成功。12SrRNA全序列测定发现两家系中所有受检的母系成员(包括12例耳聋患者)均存在nt827A→G转换,并表现为同质性突变。而非母系成员该位点序列正常。32例散发耳聋中有1例A827G突变阳性。未检测到GJB2基因、tRNAser(UCN)A7445G及12SrRNAA1555G突变。结论再次验证了mtDNA12SrRNA基因突变在母系遗传性非综合征型耳聋发病中的重要性。首次发现mtDNA12SrRNAnt827A→G转换是导致两个中国家系耳聋遗传易感性的分子基础。
Objective To investigate the relationship of associating mitoehondrial DNA 12S rRNA gene mutations with non-syndromic and aminnglycoside-induced hearing loss happening to Chinese families. Methods The diagnosis was validated by hearing tests. Blood samples were collected from 20 family members （13 subjects from pedigree A and 7 from pedigree B） and 32 sporadic deafness eases. DNA was extracted from the leukocytes in blood samples. The gene fragments of mitochondrial DNA 12S rRNA, tRNAser（UCV） and GJB2 were amplified by polymerase chain reaction （PCR）. PCR products were analyzed by sequencing, Results The target gene fragments of all individuals were successfully amplified by PCR. The mitochondrial DNA 12S rRNA 827 A to G transition was detected from all maternal members including 12 patients with hearing loss, which was the homoplasmic mutation. Non-maternal members in two pedigrees did not carry this mutation. However, the tRNA^ser（UCN） A7445G, 12S rRNA A1555G and GJB2 gene mutations were not found from both the family members of two pedigrees and sporadic patients. One sporadic individual （1/32） who was diagnosed as aminoglycoside-induced hearing impairment carried A827G mutation too. Conclusion It is confimed that the mitochondrial DNA 12S rRNA gene is a hot spot for mutations associated with non-syndromic inherited hearing loss. The 12S rRNA nt827A→G mutation may play a pivotal role in the pathogenesis of hearing impairment in two Chinese pedigrecs.
出处
《中华医学遗传学杂志》
CAS
CSCD
北大核心
2006年第4期415-418,共4页
Chinese Journal of Medical Genetics
基金
江苏省卫生厅医学重点学科开放课题(WK0623)
江苏省自然科学基金(BK2006247)
