GW24-e1197 Allele and genotype frequencies of CYP2C19 in Chinese Han population

Objectives Metabolic capacities for clopidogrel and some proton pump inhibitors (PPIs) has been reported to exhibit notable inter-individual and ethnic variability. Cytochrome P450 2C19 (CYP2C19) harbouring variant alleles has been surfaced demonstrating the main metabolising enzyme. CYP2C19*2 and CYP2C19*3 has been shown to be associated with poor metabolizer. The aim of this study was to assess the prevalence of CYP 2C19*2 and CYP 2C19*3 in Chinese Han population. Methods Blood samples were collected from 1108 unrelated Chinese Han healthy subjects for genotyping analysis. The single nucleotide polymorphisms (SNPs) CYP2C19*2 (681G>A in exon 5) and CYP2C19*3 (636G>A in exon 4) were determined by the TaqMan-Based Real-Time PCR assay. Results The frequencies of CYP2C19 genotypes *1/*1, *1/*2, *1/*3, *2/*2, *2/*3 and *3/*3 were 40%, 36%, 9%, 8%, 6% and 1%, respectively. One hundred and five subjects (15.8%) were genotypically identified as poor metabolizers of CYP2C19 genotypes *2/*2, *2/*3 and *3/*3 and the allele frequencies of the CYP2C19*2 and CYP2C19*3 were 30% and 9%, respectively. The frequencies of the prevalent defective alleles CYP2C19*2 and CYP2C19*3 in Chinese Han population are similar to those previously genotyped, and much higher than those reported in American European and other Caucasian population. Conclusions Our data may help in explaining reported inter-ethnic differences in response to drugs and could be helpful for future personalised medicine studies in Chinese Han population.