Allele and genotype frequencies of CYP2B6 and CYP3A5 in the Japanese population.
OBJECTIVE
The goal of this study was to determine the frequencies of allelic variants of CYP2B6and CYP3A5 in the Japanese population.


METHODS
Genotyping of CYP2B6 (*2, *3, *4, *5, *6, and *7) and CYP3A5 ( *2, *3, *4, *5, and *6) was carried out in 265 unrelated Japanese subjects by polymerase chain reaction (PCR), restriction fragment length polymorphism and allele-specific, real-time PCR assays.


RESULTS
Allele frequencies for CYP2B6*2, *3, *4, *5, *6, and *7 in 256 Japanese subjects were 0.047, 0, 0.093, 0.011, 0.164, and 0, respectively. Ethnic variation in allele frequencies relative to that in Caucasian subjects was observed for CYP2B6*4 (0.093 vs 0.040), *5 (0.011 vs 0.109), *6 (0.164 vs 0.256), and *7 (0 vs 0.030). Allele frequencies for CYP3A5*2, *3, *4, *5, and *6 in 265 Japanese subjects were 0, 0.740, 0, 0.004, and 0, respectively. The frequency of the CYP3A5*1 allele is 2.8 times higher in Japanese than in Caucasians.


CONCLUSIONS
Our results contribute to a better understanding of the molecular basis of ethnic differences in drug response, which may help to improve individualization of drug therapy and offer a preliminary basis for more rational use of drugs that are substrates for CYP2B6 and CYP3A5 in the Japanese population.
Hiratsuka
Masahiro
M
Department of Clinical Pharmaceutics, Tohoku Pharmaceutical University, Sendai 981-8558, Japan.
Takekuma
Yoh
Y
Endo
Naomi
N
Narahara
Kaori
K
Hamdy
Samar Ismail
SI
Kishikawa
Yukinaga
Y
Matsuura
Masaki
M
Agatsuma
Yasuyuki
Y
Inoue
Tomoko
T
Mizugaki
Michinao
M
D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D065702:Cytochrome P-450 CYP2B6; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007564:Japan; D008297:Male; D010089:Oxidoreductases, N-Demethylating / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
D003577:Cytochrome P-450 Enzyme System; D001189:Aryl Hydrocarbon Hydroxylases; C585599:CYP2B6 protein, human; C104464:CYP3A protein, human; C510164:CYP3A5 protein, human; D065702:Cytochrome P-450 CYP2B6; D051544:Cytochrome P-450 CYP3A; D010089:Oxidoreductases, N-Demethylating