Novel mutations of the CYP2A6 gene in a Thai population with lowered capacity of coumarin 7-hydroxylation.

We explored genetic polymorphisms in a Thai population which exhibited a low capacity to metabolize coumarin. The following two silent single nucleotide polymorphisms (SNPs) were found: 1) SNP, 020228Kiyotani001; GENE NAME, CYP2A6; ACCESSION NUMBER, NT_011139; LENGTH, 25 base; 5'-AAACTACCTGCAG/TCTGAACACAGAG-3'. 2) SNP, 020228Kiyotani002; GENE NAME, CYP2A6; ACCESSION NUMBER, NT_011139; LENGTH, 25 base; 5'-AATCCCCAGCAC/TTTCCTGAATGAG-3'. These two mutations (G144A and C1245T), which were located in exon 1 and exon 8 of the CYP2A6 gene, were found in two subjects among nine poor metabolizers for coumarin.