Aims: To determine the incidence of the thiopurine S-methyltransferase (TPMT) genetic polymorphism in the Thai population.
Methods: Genomic DNAs were isolated from peripheral blood leucocytes of 200 healthy Thais. The frequencies of five allelic variants of the TPMT gene, TPMT*2, *3A, *3B, *3C and *6 were determined using allele specific polymerase chain reaction (PCR) or PCR-Restriction fragment length polymorphism technique.