Objective: This study was to investigate the gene mutation of thiopurine S-methyltransferase (TPMT) in Uygur Chinese. Methods: Polymerase chain reaction-based methods were used to analyze three commonly reported inactivating mutations-G238C, G460A and A719G. Results: One TPMT*3A heterozygote and five TPMT*3C heterozygotes were found in 160 Uygur Chinese subjects, and allele frequencies of TPMT*3A and TPMT*3C were 0.3% and 1.6%, respectively. Conclusion: TPMT*3C is a common mutant allele in Uygur Chinese, while TPMT*3A is a rare mutant allele in Uygur Chinese.

Objective. This study was conducted to investigate the thiopurine S-methyltransferase (TPMT) activity distribution and gene mutations in Kazaks, and compared the results with those of other ethnic groups. Methods. Erythrocyte TPMT activity was measured in Kazaks (n=327) via a validated highperformance liquid chromatography assay. Polymerase chain reaction-based methods were used to analyze three commonly reporter-inactivating mutations: G238C, G460A, and A719G. Results. Unimodal distribution of TPMT activity was found in Kazaks. Six TPMT*3C heterozygotes and two TPMT*3A heterozygotes were found in 327 Kazaks, with allele frequencies of 0.9 and 0.3%, respectively. The subjects with TPMT*3A and TPMT*3C heterogygotes had substantial TPMT activity over the range of 6.40Y11.75 U/ml RBC. Conclusion. Unlike in most Caucasians, TPMT*3C is a common mutant allele in Kazaks, whereas TPMT*3A is a rare mutant allele. Further studies are needed to explore the clinical impact of these TPMT mutants to thiopurine therapy in Kazak patients.