Genetic polymorphism of cytochrome P450 2B6 in a Korean population

CYP2B6 gene shows genetic polymorphisms with interethnic variations, but no reports have been addressed in Korean population. Allelic distribution of CYP2B6*4, *5, *6, *7, and *9 was evaluated in a Korean population. Genotype was determined by PCR-RFLP analysis of three loci (G516T, A785G, and C1459T) in 86 healthy Korean subjects. There were no subjects with either CYP2B6*5 or *7, both of which include a C1459T mutation. Of 86 subjects, 37, 12, 8, 2, 1, and 2 subjects had genotypes of CYP2B6*1/*1, *1/*4, *1/*9, *4/*6, *6/*9, and *6/*6, respectively. And 24 subjects were found to have either CYP2B6*1/*6 or *4/*9 genotypes. Due to the absence of information on gametic phase, allelic frequencies of CYP2B6*4 (A785G), *6 (A785G, G516T), and *9 (G516T) could not be determined directly from PCR-RFLP method. Haplotype frequencies of CYP2B6*4, *6 and *9 were expected by Expectation-Maximization algorithm. The allelic frequencies of CYP2B6*4, *6 and *9 were 8.7%, 17.5%, and 5.8%, respectively. Allelic frequencies of CYP2B6*4 and *6 in Korean are similar to those of Japanese but different from those of Caucasians (Chi-square test, p<0.1). Further, CYP2B6*5, which is known to decrease CYP2B6 activity in vivo and found in Caucasians with high frequency (10.9%), was rarely found in Korean (0%) and Japanese (1.1%). Our results suggest that in the context of genetic polymorphism of CYP2B6 Korean population is similar to Japanese but significantly different from Caucasians. Clinical Pharmacology & Therapeutics (2004) 75, P68–P68; doi: 10.1016/j.clpt.2003.11.254