Frequency of the CYP2C19*10 Allele in the Korean Population

The CYP2C19 gene has a high proportion of poor metabolizers (PMs) in Asians, including Koreans, with the CYP2C19*2 and *3 alleles accounting for most of the PMs.CYP2C19*10 is a mutation that differs by 1 bp from CYP2C19*2 and cannot be distinguished by the conventional PCR-RFLP method using SmaI.Thus, the frequency of CYP2C19*10 may appear high in an ethnic group with a high frequency of CYP2C19*2.We classified CYP2C19*2 and *10 using the pyrosequencing method and carried out a study to accurately confirm their frequency.Four hundred and thirty-two healthy Korean subjects were studied.CYP2C19 alleles (CYP2C19*2, *3, *10, and *17) were detected using pyrosequencing assays.The allele frequencies observed here were 63.0% for CYP2C19*1, 26.4% for CYP2C19*2, 9.4% for CYP2C19*3, and 1.3% for CY-P2C19*17.The CYP2C19*10 allele was not detected.The frequencies of the CYP2C19 normal metabolizer, rapid metabolizer, intermediate metabolizer, and PM phenotypes were 40.0%, 1.6%, 45.1%, and 13.2%, respectively.Similar to previous studies, the frequencies of CYP2C19*2 and *3 were relatively high, and the frequency of CYP2C19*17 was low.Finally, in Koreans, the frequency of CYP2C19*10 seems to be extremely low.