Development and validation of a rapid and reliable method for TPMT genotyping using real-time PCR.

Background: It is widely accepted that many medications exhibit inter-individual variability in their efficacy and toxicity due to polymorphisms in genes encoding drug-metabolising enzymes. One of the most often cited examples in this context is thiopurine S-methyltransferase (TPMT) polymorphism. TPMT is a phase 2 detoxification enzyme that catalyzes the S-methylation of thiopurine drugs such as thioguanine and 6-mercaptopurine.