Allele and genotype frequencies of CYP2C9 in a Korean population

Aims: To determine the frequencies of the variant alleles and the genotypes of CYP2C9 in a Korean population. Methods: Three hundred and fifty-eight healthy Korean subjects were studied. CYP2C9 alleles were detected by polymerase chain reaction-restriction fragment length polymorphism assays and direct sequencing assays. Results: The allele frequencies were 0.934 for CYP2C9*1, 0.060 for CYP2C9*3 and 0.006 for CYP2C9*13. The CYP2C9*2, *4, *5 and *11 alleles were not detected. The frequencies of the CYP2C9*1/*1, *1/*3 and *1/*13 genotypes were 0.869, 0.120 and 0.011, respectively. Conclusion: The frequency of the CYP2C9*3 allele in the Korean population studied was significantly higher than reported elsewhere, and a novel allele, CYP2C9*13, was found at a frequency of 0.006 (95% confidence interval 0, 0.012). Only three genotypes of CYP2C9, CYP2C9*1/*1, *1/*3 and *1/*13 were observed in this Korean population.