中国藏族人群具有低CCR5Δ32、高CCR2b-64I突变型基因频率

目的：调查CCR5△32、CCR5m303、CCR2b-64I和SDF1－3’A等人类免疫缺陷病毒（humanimmune deficiency virus-1,HIV-1)相关的等位基因在中国藏族人群中的频率和分布情况。方法：随机采集血样，提取基因组DNA，经PCR或PCR－RFLP分析，计算突变形基因频率，并对其群体分布、性别分布以及其相关性进行统计学分析。结果：发现藏族人的CCR5△32和CCR5m303突变型基因频率均小于0．15％；SDF1－3’A和CCR2b-64I突变型基因频率分别为19．24％和29．42％。4种突变等位基因群体分布均符合Hardy-Weinberg平衡，性别之间差异无显著性。虽然中国藏族人群CCR2b-64I的突变型基因频率较高，但CCR5△32和SDF1－3’A的突变型基因频率低，提示中国藏族人群很可能在遗传上是HIV－1易感的人群。结论：中国藏族人群与西方白人相比可能具有低CCR5△32和高CCR2b-64I等位基因突变频率。

CCR2b-64I alleles

OBJECTIVE: To investigate the allelic polymorphism of CCR5triangle32, CCR5m303, CCR2b-64I and SDF1-3'A in Tibetan population in Lasa area of China. METHODS: The genomic DNA samples from 330 Tibetan subjects' whole blood samples were purified by use of QIAgen Blood Kit and identified by PCR or PCR-RFLP analyses. RESULTS: The mutation frequencies of CCR5triangle32 and CCR5m303 alleles were lower than 0.15%, and those of CCR2 b-64I and SDF1-3'A alleles were 29.42% and 19.24% respectively in the study samples. The allelic polymorphisms of the four alleles of Tibetan population were similar to those of Chinese Han population. Genotype distribution of the four alleles was in accordance with Hardy-Weinberg equilibrium. The above results suggest that Tibetan population may be relatively susceptive to HIV-1. CONCLUSION: The Chinese Tibetan may have a lower frequency of CCR5triangle32 and a higher frequency of CCR2b-64I allele, compared with Caucasian.