非综合征型耳聋与线粒体基因突变荟萃分析及相关突变筛查研究

发布时间：2019-02-21 18:15

【摘要】：听力损失是一种比较常见的听力缺陷疾病,给患者的正常生活带来了极大的不便,同时给家人和社会带来了巨大的经济压力。据报道,近60%先天性耳聋的发生和遗传有紧密的联系,线粒体DNA(mitochondrial DNA,mtDNA)突变是导致非综合征型耳聋(non-syndromic hearing loss,NSHL)的重要原因之一,且氨基糖苷类抗生素(aminoglycoside antibiotics,AmAn)的使用是mtDNA突变致聋的主要诱因,但目前对于哪些mtDNA突变位点与NSHL存在相关性还不是很清楚。目前,新生儿耳聋基因筛查日益广泛,通过筛查耳聋相关mtDNA突变位点和其他基因相关突变位点,预防氨基糖苷类抗生素致聋(aminoglycoside antibiotics induced deafness,AAID)和迟发性听力损失的发生,进而降低耳聋的发生率。本文主要研究与NSHL和AAID显著相关的mtDNA突变位点并且进一步研究通过筛查这些mtDNA突变位点和其他已经明确的耳聋基因热点突变位点是否可以降低NSHL的发生率。为了系统地分析已报道的mtDNA突变位点在不同种族中NSHL和AAID的相关性,本研究对43篇文献中的122个mtDNA突变位点与NSHL的相关性进行了评估,发现了8个位点与NSHL显著相关,其中7个位点(961ins/del,A1382C,A1555G,C1494T,G988A,A1557C,C1009T)位于MT-RNR1上,1个位点(G15927A)位于MT-TT上。6个位点(A1027G,A1555G,A839G,C1494T,T1095C,T1107C)与AAID显著相关。经RNA折叠模型分析和保守性分析,发现这6个位点在不同物种中高度保守且其中5个位点(A1555G,A839G,C1494T,T1095C,T1107C)可能位于12S rRNA基因AmAn的结合区,表明这些位点突变可能会导致12S rRNA结构变异,增强其与AmAn的结合,进而导致AAID的发生。将荟萃分析鉴定的在亚洲人群中与NSHL和AAID显著相关的mtDNA位点(A1555G,C1494T)和已报道的在亚洲人群中与NSHL显著相关的突变位点(GJB2235delC,SLC26A4 A919G)纳入武汉地区新生儿耳聋基因筛查研究。采用荧光定量PCR方法结合测序法检测上述四个位点。本研究从66281例新生儿中筛查出2001例耳聋基因突变者,4位点总检出率为3.018%。根据本次的检测结果可以对携带基因突变的新生儿提早制定相应的干预措施,有助于降低武汉地区耳聋的发病率;建立了一套关于大规模耳聋基因筛查流程;继续跟踪携带基因突变的新生儿的耳聋发病情况以评估基因筛查的效益。综上所述,本研究利用荟萃分析的方法探讨了mtDNA突变与NSHL和AAID的相关性,与NSHL和AAID显著相关的突变位点可以作为新生儿耳聋易感基因筛查的候选位点,进而将荟萃分析鉴定出的mtDNA A1555G和C1494T两位点纳入武汉地区新生儿耳聋基因筛查研究,进而通过大规模耳聋基因筛查,降低耳聋的发病率。
[Abstract]:Hearing loss is a relatively common hearing impairment disease, which brings great inconvenience to patients' normal life, and brings great economic pressure to family and society at the same time. It is reported that nearly 60% of congenital deafness is closely related to heredity. Mitochondrial DNA (mitochondrial DNA,mtDNA mutation is one of the important causes of non-syndromic deafness (non-syndromic hearing loss,NSHL), and aminoglycoside antibiotic (aminoglycoside antibiotics, The use of AmAn is the main cause of deafness caused by mtDNA mutation, but it is not clear which mtDNA mutation sites are correlated with NSHL. At present, gene screening for neonatal deafness is becoming more and more widespread. By screening deafness related mtDNA mutation sites and other gene related mutation sites, the occurrence of aminoglycoside antibiotic induced deafness (aminoglycoside antibiotics induced deafness,AAID) and delayed hearing loss is prevented. And then reduce the incidence of deafness. In this paper, we studied the mtDNA mutation sites significantly related to NSHL and AAID and further studied whether screening these mtDNA mutation sites and other hot spot mutation sites of deafness gene could reduce the incidence of NSHL. In order to systematically analyze the correlation between NSHL and AAID in reported mtDNA mutation loci in different ethnic groups, 122 mtDNA mutation sites in 43 articles were evaluated for their correlation with NSHL, and 8 sites were found to be significantly correlated with NSHL. Seven loci (961insdelA1382CMT-RNR1 A1555GN C1494TG1494TG988A1557CU C1009T) were located on MT-RNR1, one locus (G15927A) was located on MT-TT, and six loci (A1027GUA1555GMT-RNR1 A839GC1494TC1494TT1095CT1107C) were significantly correlated with AAID. By RNA folding model analysis and conserved analysis, it was found that the six loci were highly conserved in different species and that five of them (A1555GN A839GC1494TT1095CRNA T1107C) might be located in the binding region of 12s rRNA gene AmAn. These mutations may lead to structural variation of 12s rRNA, enhance its binding with AmAn, and lead to the occurrence of AAID. The mtDNA loci (A1555GG, C1494T) and GJB2235delC,SLC26A4 A919G (GJB2235delC,SLC26A4 A919G), which were significantly associated with NSHL and AAID, were identified by meta-analysis in Asian population and were included in the genetic screening study of neonatal deafness in Wuhan. The four loci were detected by fluorescence quantitative PCR and sequencing. In this study, 2001 deafness gene mutants were screened from 66281 newborns. The total detection rate of 4 loci was 3.018. According to the results of this test, early intervention measures can be made for newborns with gene mutation, which will help to reduce the incidence of deafness in Wuhan, and establish a set of screening procedures for large-scale deafness gene. Continue to track deafness in newborns with mutations to assess the effectiveness of genetic screening. To sum up, we used meta-analysis to explore the correlation between mtDNA mutation and NSHL and AAID. The mutation sites significantly related to NSHL and AAID could be used as candidate sites for screening susceptibility genes for neonatal hearing loss. Then, the mtDNA A1555G and C1494T loci identified by meta-analysis were included in the screening study of newborn deafness gene in Wuhan area, and the incidence of deafness was reduced through large-scale deafness gene screening.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R764.43

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