Subjects (n=189) were analyzed for CYP2A6 copy number and genotyped for eight other polymorphisms previously reported as potentially associated with CYP2A6 mRNA expression or enzyme activity. A summary of haplotypes defined by these polymorphisms is presented in Table 1. Sequencing within CYP2A6 exons identified six additional non-synonymous SNPs in four individuals. Two individuals carried a novel coding SNP, 5023A>G (chromosome 19 position 41,351,309 GRCh37, *1D Y351H, Table 1), one individual with diplotype *1B/*12 carried the minor alleles of two SNPs, rs2644906 (4372G>A) and rs4997557 (4379C>G), resulting in the amino acid changes V292M and T294S respectively, and one *9/*1A individual carried the minor alleles of three SNPs, rs28399463 (5745A>G), rs8192730 (5750G>C) and rs6413474 (6573A>G), resulting in amino acid changes N418D, E419D and K476R respectively.
