title: Allele and genotype frequencies of CYP2B6 and CYP3A5 in the Japanese population.
abstract: 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.
authors.affiliation: Department of Clinical Pharmaceutics, Tohoku Pharmaceutical University, Sendai 981-8558, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hiratsuka
authors.forename: Yoh
authors.initials: Y
authors.lastname: Takekuma
authors.forename: Naomi
authors.initials: N
authors.lastname: Endo
authors.forename: Kaori
authors.initials: K
authors.lastname: Narahara
authors.forename: Samar Ismail
authors.initials: SI
authors.lastname: Hamdy
authors.forename: Yukinaga
authors.initials: Y
authors.lastname: Kishikawa
authors.forename: Masaki
authors.initials: M
authors.lastname: Matsuura
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Agatsuma
authors.forename: Tomoko
authors.initials: T
authors.lastname: Inoue
authors.forename: Michinao
authors.initials: M
authors.lastname: Mizugaki
mesh_terms: 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
chemical_list: 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