Three novel single nucleotide polymorphisms of the human thiopurine S-methyltransferase gene in Japanese individuals

In this study, the entire coding sequence and the exon-intron junctions of the thiopurine S-methyltransferase (TPMT) gene from 200 Japanese individuals were screened for mutation. Three novel single nucleotide polymorphisms (SNPs) were identified-106G>A in exon 3 (Gly36Ser, *20 allele), 967A>G in 3'-untranslated region, and -87C>T in intron 8. The allele frequencies were 0.003 for 106G>A, 0.003 for 967A>G, and 0.010 for IVS8 -87C>T. In addition, the three known SNPs, 474T>C (Ile158Ile), 719A>G (Tyr240Cys, *3C allele), and IVS4 +35C>T were detected at frequencies of 0.299, 0.010, and 0.421, respectively.