Allelotype frequency of the thiopurine methyltransferase (TPMT) gene in Japanese

Polymorphisms at three loci in the thiopurine methyltransferase (TPMT) gene are known to be responsible for azathioprine and 6-mercaptopurine (6MP) to xicity. Among them, only TPMT*3C variant. allele with A719G mutation was fo und in 15/522 (2.9%; 17/1044 alleles; 1.6%) Japanese individuals including two homozygotes. The allele frequency was different from that in Caucasians , and investigation of TPMT polymorphisms with consideration of ethnic diff erences before administration of azathioprine or GMP map provide clinically useful information, Pharmacogenetics 11:275-278 (C) 2001 Lippincott Willia ms & Wilkins.