军事噪声性听力损失的线粒体基因变异分析

Analysis of mitochondrial DNA gene mutations in hearing loss induced by military noise

目的研究线粒体基因变异与军事噪声性听力损失遗传易感性的关系,为确定噪声易感个体的分子诊断方法提供依据。方法对云南某部接触军事噪声的406名坦克兵、626名炮兵共计1032例进行听力损失调查,收集军事噪声易感者(易感组)82例,耐受者(耐受组)40例,共计122例。分别采集外周静脉血标本,从白细胞中提取DNA,PCR扩增线粒体DNA及非综合征型耳聋相关的热点突变部分片段,进行基因测序比对分析,比较两组中存在碱基改变的位点分布例数。对测序结果中存在与耳聋相关的碱基改变的个体做进一步的听力学分析。结果军事噪声易感者和耐受者的线粒体基因存在一定差异,线粒体COII基因T7684C和G7853A两个位点的变化只存在于易感组,两组间有显著性差异(P<0.05)。A827G、T961insC(异质)、T1005C、T1095C、G7444A等可能与耳聋相关的线粒体基因改变多见于易感组,耐受组也有分布。结论携带线粒体COII基因T7684C和G7853A碱基变化的个体可能对军事噪声更加易感。

Objective To investigate the relationship between mitochondrial DNA gene mutations and the susceptibility to military noise, and to provide a criterion for screening the individuals susceptible to military noise through molecular biology diagnostic method. Methods An investigation of hearing loss was performed among a total of 1032 servicemen including 406 tankers and 626 artillerymen who have endured military noise in their military duty. A total of 122 blood samples were collected, of which 82 samples were collected from susceptible individuals （susceptible group） and 40 from tolerance individuals （tolerance group）. DNA was then extracted from the leukocytes of blood samples. The gene fragments of mitochondrial DNA, which might associate with non-syndromal heating loss, were amplified by polymerase chain reaction （PCR） . The PCR products were analyzed by sequencing and contrasting. The gene mutations which were different from the standard sequences of mitochondrial genome were then compared between the susceptible and tolerance groups. Further auditory analysis was performed on those persons who had the gene mutations of hearing loss. Results The gene sequencing revealed there were definite differences in mitochondrial DNA between the susceptible and tolerance groups, and statistically significant difference was found in mitochondrial DNA COⅡ gene T7684C and G7853A mutations between the two groups. Mitochondrial DNA gene mutations were found in the present study, such as A827G, T96linsC （heterogeneity）, T1005C, T1095C and G7444A, which were reported to be related to deafness in literature. Most of these mutations were detected from the samples of susceptible group, and the others from tolerance group. Conclusion The mitochondrial DNA COⅡ gene T7684C and G7853A mutations might exist in those persons who are susceptible to military noise.