SHORT COMMUNICATIONEthnic variation in CYP2A6*7, CYP2A6*8 and CYP2A6*10 as assessed with a novel haplotyping methodMwenifumbo, Jill C.a; Myers, Mark G.b; Wall, Tamara L.b; Lin, Shih-Kuc; Sellers, Edward M.a d; Tyndale, Rachel F.a dAuthor Information aUniversity of Toronto, Toronto, Canada bVeterans Medical Research Foundation, San Diego and University of California, San Diego, California, USA cDepartment of Addiction Science, Taipei City Psychiatric Center, Taipei, Taiwan dCentre for Addiction Mental Health and Department of Pharmacology, Toronto, Canada Sponsorship: CIHR MOP-53248, The Center for Addiction and Mental Health and California Tobacco Related Disease Research Program grants 10RT-0142 and 12RT-0004, supported this study. J.C.M. receives funding from CIHR-STPTR, T.L.W. receives funding from NIH K02 AA00269, and R.F.T. holds a Canadian Research Chair in Pharmacogenetics. Correspondence and requests for reprints to Rachel F. Tyndale, Room 4326 Medical Sciences Building, 1 King's College Circle, University of Toronto, Toronto, Ontario M5S 1A8, Canada E-mail: [email protected] Received 21 October 2004 Accepted 4 January 2005 Pharmacogenetics and Genomics: March 2005 - Volume 15 - Issue 3 - p 189-192 Buy 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. © 2005 Lippincott Williams & Wilkins, Inc.