Frequencies of genotypes and alleles of the functional SNPs in CYP2C19 and CYP2E1 in mainland Chinese Kazakh, Uygur and Han populations.

CYP2C19 and CYP2E1 show great genetic differences between Orientals and Caucasians. The objective of this study was to investigate the genotype and allele distribution patterns of CYP2C19 and CYP2E1 polymorphisms among healthy participants in mainland Chinese Kazakh, Uygur and Han populations by the PCR-restriction fragment length polymorphism technique. The allele frequencies of CYP2C19 2, CYP2E1 5B and CYP2E1 6 were significantly lower in the Chinese Kazakh (15.4, 11.2 and 14.5%, respectively) (P<0.05) and Uygur (16.1, 12.1 and 18.8%) (P<0.05) populations than that in the Chinese Han population (28.8, 19.4 and 26.2%), but the frequencies of CYP2C19 3 were similar among the three populations (8.0, 9.4 and 7.2%). Frequencies of the three combined genotypes, one for predicted CYP2C19 poor metabolizers and two for predicted high levels of CYP2E1 transcription, were significantly lower in the Chinese Kazakh (7.5, 19.6 and 28.0%, respectively) (P<0.05, chi(2)-test) and Uygur (8.1, 22.8 and 33.6%) (P<0.05) populations compared with the Chinese Han population (16.5, 35.9 and 44.7%). The present research shows that frequencies of the functional single-nucleotide polymorphisms in the CYP2C19 and CYP2E1 genes vary in the Chinese Kazakh, Uygur and Han populations, suggesting that disease susceptibilities or drug responses associated with enzyme activities of CYP2C19 and CYP2E1 may differ in the diverse ethnic populations in mainland China.