过氧化氢酶基因389C>T多态位点在重庆汉族人群中的分布及其与噪音性耳聋的关联研究

Relationship between 389 C > T polymorphism of catalase gene and noise-induced hearing loss in Han population of Chongqing

目的探讨过氧化氢酶(catalase,CAT)基因外显子区第9外显子的同义突变位点389C>T(rs769217)多态性在重庆汉族人群中的分布及其与噪音性耳聋的关联研究。方法以中国重庆地区汉族无血缘关系的健康志愿者225例,噪声接触者427例作为研究对象。噪音接触者根据接触噪声后是否出现噪音性听力丧失(noise-induced hearing loss,NIHL)又分为非耳聋组,即NIHL(-)组(n=303)和耳聋组,即NIHL(+)组(n=124)。采用上海天昊公司的专利技术iMLDRTM分型技术,分别检测各组CAT基因389 C>T多态位点的基因型,并比较组间基因型、等位基因频率分布及临床变量间的差异。结果在研究人群中检测到CAT基因389C>T多态位点的3种基因型CC、CT和TT,2组人群的T等位基因频率均为0.46,C等位基因频率为0.54,健康对照组和噪音接触组基因型频率分布符合Hardy-Weinberg遗传平衡定律(P>0.05)。健康对照组与噪音接触组、健康对照组与NIHL(-)组间CAT基因389C>T多态位点的3种基因型(CC、CT和TT)和等位基因(C、T)频率分布均无显性差异(P>0.05);但健康对照组与NIHL(+)组及NIHL(-)组与NIHL(+)组间3种基因型(CC、CT和TT)和等位基因(C、T)频率分布均有显著性差异(P<0.05),且显性模型分析中即TT+CC vs CC均有显著性差异(P<0.05)。结论 389C>T位点(rs769217)与重庆汉族人群中NIHL遗传易感性有关联,在重庆汉族人群中可作为噪音性耳聋易感性的生物标志。

Objective To explore the distribution of 389 C 〉 T （rs769217） polymorphism of catalase （CAT） gene in Han population of Chongqing, China, and the relationship between the polymorphism and noise-induced hearing loss （NIHL）. Methods In Chongqing, China, 427 unrelated adult Chinese Han people who were exposed to noise （ noise exposure group） and 225 healthy volunteers without exposure （ control group） were included in the study. The noise exposure group was further divided into NIHL （ - ） group （with- out NIHL, n =303） and NIHL （ ＋ ） group （with NIHL, n = 124）. An improved multiplex ligation detection reaction （iMLDR） technique was employed to detect genotypes of 389 C 〉 T polymorphism of CAT gene. Allelic frequencies and clinical characteristics were compared among these groups. Results Three genotypes, CC, CT and TI＇, were detected. The frequencies of C and T allele of the CAT gene 389 C 〉 T polymorphism were 0. 46 and 0.54 respectively. The genotype distribution in the control group and noise exposure group was in agreement with the Hardy-Weinberg equilibrium （P 〉 0. 05 ）. There was no significant difference in genotypic （CC, CT, TT） and allelic frequencies （C, T） between the control group and noise exposure group and between the control group and NIHL （ - ） group （P 〉 0. 05 ）. However. significant differences were observed between the control group and NIHL （ ＋ ） group and between the NIHL （ - ） group and NIHL （ ＋ ） group （ P 〈 0. 05 ）, especially in the case of dominant association effect （ TT ＋ CT vs CC, P 〈 0.05 ）. Conclusion The person who is exposed to noise with the T variant allele has significantly higher NIHL morbidity than those with homozygous C allele. CAT gene 389 C 〉 T polymorphism may be used as a biomarker for the assessment of NIHL morbidity in Chongqing Han population .