Graphic roots of CYP2C19 genetic polymorphism in Japanese population (preliminary report)

Abstract

The genetic polymorphism of CYP2C19 was examined in two groups in Japanese subjects, 57 living in the Tohoku area for three generations (Tohoku population) and 57 living in areas other than Tohoku for the three generations (general Japanese population). The frequency of CYP2C19 genotype analysis for CYP2C19*1, *2 and *3 were examined by the polymerase chain reaction-restriction enzyme genotyping (PCR-RFLP). The frequency of poor metabolizers (PM) was 17.5% in the Tohoku population and 14.0% in the general Japanese population, respectively. The frequency of homozygous wild-type (*1*1) extensive metabolizers (EM) of the CYP2C19 in general Japanese population (40.8%) was significantly greater than that of the Tohoku population (21.3%). However, the frequency of heterozygous EM (*1*2) in the Tohoku population (44.7%) was higher than that of the general Japanese population (28.5%). Our results show a different incidence of the CYP2C19*1 and the *2 allele between the general Japanese and Tohoku populations. It is suggested that the localization of the CYP2C19*2 allele in the Tohoku population occurred in the evolutionary process of the Japanese population.