title: Ethnic variation in CYP2A6*7, CYP2A6*8 and CYP2A6*10 as assessed with a novel haplotyping method.
abstract: Cytochrome P450 2A6 is the main human nicotine metabolizing enzyme coded for by a highly polymorphic gene, CYP2A6. CYP2A6*7, CYP2A6*8 and CYP2A6*10 are variant alleles common to Asian ethnicities. The CYP2A6*7 and CYP2A6*8 alleles each contain a non-synonymous single nucleotide polymorphism (SNP) 6558T>C and 6600G>T, respectively, whereas the CYP2A6*10 haplotype allele contains both. We have developed the first haplotyping assay; it can unambiguously distinguish the CYP2A6*7, CYP2A6*8 and CYP2A6*10 alleles. The allele frequencies of these three variants were assessed using the novel haplotyping assay in Chinese-Canadian (n=112), Chinese-American (n=221), Taiwanese (n=319), Korean-American (n=207) and Japanese-Canadian (n=64) populations, as well as in Caucasian (n=110) and African-Canadian (n=113) populations. Our new method demonstrated higher frequencies of CYP2A6*7 and CYP2A6*10, and a lower frequency of CYP2A6*8 in Asian populations, but no significant change of allele frequencies in Caucasian or African-Canadian populations.
authors.affiliation: University of Toronto, Toronto, Canada.
authors.forename: Jill C
authors.initials: JC
authors.lastname: Mwenifumbo
authors.forename: Mark G
authors.initials: MG
authors.lastname: Myers
authors.forename: Tamara L
authors.initials: TL
authors.lastname: Wall
authors.forename: Shih-Ku
authors.initials: SK
authors.lastname: Lin
authors.forename: Edward M
authors.initials: EM
authors.lastname: Sellers
authors.forename: Rachel F
authors.initials: RF
authors.lastname: Tyndale
mesh_terms: D000349:Africa; D000483:Alleles; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D044466:Asian People; D044383:Black People; D002170:Canada; D002681:China; D065637:Cytochrome P-450 CYP2A6; D005091:Exons; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007564:Japan; D007723:Korea; D006899:Mixed Function Oxygenases / Q000235:genetics*; D008957:Models, Genetic; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D012907:Smoking; D013624:Taiwan; D014481:United States; D044465:White People; D001741:Black or African American
chemical_list: D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C585710:CYP2A6 protein, human; D065637:Cytochrome P-450 CYP2A6