Distribution of the CCR5 Gene 32-Base Pair Deletion and CCR5 Expression in Chinese Minorities

Abstract

China has an ethnically diverse population. Genetic differences may contribute to disparities in the efficiency of HIV transmission. To further characterize this risk, we examined the HIV-related genetic diversity in the predominant Han Chinese and in six minority groups. We searched for the delta32-CCR5 mutation, a common cause of relative HIV resistance in the white population. In addition, CCR5 receptor expression was measured. Blood samples were obtained from adults belonging to the Han, Meng, Zang, Weiwuer, Zhuang, Yi, and Dai ethnic groups. Polymerase chain reaction analysis was performed on genomic DNA samples. Surface expression of CCR5 on peripheral blood mononuclear cells was measured by flow cytometry. One-way ANOVA was used to determine mean statistical differences. Samples from 10 members of each minority were examined. A delta32-CCR5 heterozygote phenotype was detected in one Weiwuer subject, but no mutations were found in the other 69 subjects studied. The mean CCR5 expression of cells harvested from the Dai minority was greater than that of cells from all other minorities studied, for both CD3+CCR5+ and CD4+CCR5+ sets (p < .01, one-way ANOVA). The delta32-CCR5 mutation seems to be rare in most Han Chinese and the minority populations studied. CCR5 expression appears to be greater in the Dai minority than in the other minorities investigated. The mechanism for this increased expression requires further study.

Global human genetics of HIV-1 infection and China

“…Heterozygous CCR5-32 genotypes were found in 3 out of 1254 Han Chinese, with an allele frequency of 0.00119. Findings from this study and others [88,89] show that CCR5-32 mutants do occur in Chinese population (all are individuals with heterozygous CCR5-32), and can be inherited at a very low frequency [87][88][89].…”

“…The polymorphism demonstrates a decreasing north-south cline across Eurasia and is largely absent in African, Asian and Oceanic populations [84][85][86], interestingly this distribution may have become fixed 700 years ago in northwestern Europe [86]. Indeed, studies to date indicate that CCR5-32 mutant alleles were absent or infrequent in Chinese [87][88][89][90][91][92][93]. Homozygous genotypes have not been identified in Chinese populations, while heterozygous CCR5-32 is extremely rare or absent in most Chinese populations studied [87][88][89][90][91][92][93].…”

“…The frequencies of heterozygous and homozygous CCR2-64I in Chinese were 13-35% and 1-8%, respectively, varying from study to study [87][88][89][90][91][92][93]. There is no difference in the frequencies of both heterozygous and homozygous CCR2-64I between HIV-1 infected and HIV seronegative individuals, suggesting no association of CCR2-64I with HIV-1 transmission in Chinese.…”

“…There is no difference in the frequencies of both heterozygous and homozygous CCR2-64I between HIV-1 infected and HIV seronegative individuals, suggesting no association of CCR2-64I with HIV-1 transmission in Chinese. There is also generally no evidence of association of CCR2-64I with disease progression in HIV-1 infected Chinese individuals [87][88][89][90][91][92][93]. The allelic frequency of CCR2-64I was about 20% (95% CI, 15~30%) [87][88][89][90][91][92][93], which is significantly higher than that in other ethnic groups including Caucasians.…”

“…Indeed, studies to date indicate that CCR5-32 mutant alleles were absent or infrequent in Chinese [87][88][89][90][91][92][93]. Homozygous genotypes have not been identified in Chinese populations, while heterozygous CCR5-32 is extremely rare or absent in most Chinese populations studied [87][88][89][90][91][92][93]. There is no evidence that CCR5-32 influences the HIV-1 transmission or epidemic in China.…”