The medicine 6-Mercaptopurine (6-MP) is metabolized by TPMT. Individual differences in TPMT activity associated with SNPs rs1800460, rs1142345, and rs1800462 are relevant in determining appropriate dosage range and interval for treatment.
Variation in ITPA may also effect 6-Mercaptopurine metabolism (see rs1127354), however, the effect seen was smaller than that of the TPMT mutations observed.
See PharmGKB for more on 6-MT and other thiopurines.
