摘要目的为了评估中国汉族人群对HIV感染的遗传易感性,我们检测和分析了相应人群的CCR5-△32、 CCR2-64I和SDF1-3'A等位基因的突变频率和多态性. 方法被研究的人群包括1254例中国普通汉族人(918例男性、336例女性),年龄范围在15-80岁之间, 他们中没有HIV感染者.应用PCR和PCR/RFLP等分子生物学方法检测了CCR5-△32、CCR2-64I和SDF1- 3'A等位基因型,用直接DNA测序法进一步证实其准确性. 结果我们发现在汉族人的CCR5基因编码中的确存在△32碱基缺失突变(频率为0.00119,n=1254),并可能经过孟德尔方式遗传;而CCR2-64I和SDF1-3'A等位基因的突变频率分别是0.20023(n=1251)和 0.2873(n=893).可见汉族人群的CCR2-64I和SDF1-3'A突变频率高于美国白人,并且在基因多态性组成上与美国白人不同.统计学分析表明中国汉族人群中上述三个等位基因型的分布符合Hardy-Weinberg 平衡.结论上述结果提示中国汉族人群中CCR5-△32遗传突变可能不是抗HIV感染的主要因素,因此汉族人群对性传播的R-5病毒株可能有较大的遗传易感性.中国汉族人群具有较高的CCR2-64I和SDF1-3'A等位基因突变频率及其在抗HIV感染中的意义尚待阐明.

abstractsObjective To evaluate the frequencies and polymorphisms of CCR5-△32,CCR2-641 and SDF1-3'A alleles conferring resistance to HIV-1 infection in Chinese population from Han ethnic origin.Methods This cohort was comprised of 1251 subjects(915 men and 336 women)aged 15 -80 years and none was HIV-1 positive.Genotyping of allelic CCR5-△32,CCR2-641 and SDF1-3' A variants was performed using PCR or PCR/RFLP assay,and further confirmed by direct DNA sequencing.Results Our finding shows that the△32 deletion mutation in the CCR5 gene does occur in this population and can be inherited in a Mendelian fashion in indigenous Han Chinese at a very low frequency of 0.00119(n= 1254).The frequencies of mutant CCR2-641 and SDF1-3'A alleles were 0.20023(n = 1251)and 0.2873(n = 893),in this population,which are higher than those found in American Caucasians.Furthermore the polymorphisms of CCR2-641 and SDF1-3' A alleles in the Han Chinese population were different from those in American Caucasians.Statistical analysis showed that the genotype distribution of CCR5-△32,CCR2-641 and SDF1-3' A alleles was in equilibrium according to the Hardy-Weinberg equation.Conclusion The CCR5-△32 mutation may not be a major resistant factor against HIV-1 infection in indigenous Han Chinese.The significance of higher frequencies of CCR2-641 and SDF1-3' A alleles (0.20023 and 0.2791)in the Han population remains to be clarified in HIV-1-positive carriers and AIDS patients.