Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme that catalyzes S-methylation (inactivation) of thiopurine drugs such as anticancer (6-mercaptopurine and 6-thioguanine) and immunosuppressant agents (azathioprine).

These drugs are widely used for treatment of:
1. cancers
2. leukemias
3. autoimmune diseases
4. inflammatory bowel disease (ulcerous colitis, Crohn's disease)

Decreased activity of TPMT is associated with severe hematopoietic toxicity after using standard doses of these drugs. Moreover, this toxicity can be fatal. There are several mutations in TPMT gene which give rise to low phenotypic activity. The doses of administered thiopurine drugs are reduced regarding patients' genotype character. After that, patients do not develop hematopoietic toxicity complications.

Mutations detected in the Laboratory for Molecular Hematology by DNA analysis are: TPMT(G238C), TPMT (G460A) and TPMT (A719G).

CONTACT: Dr Sonja Pavlović

TEL: ++ 381 11 3976 445

FAX: ++ 381 11 3975 808

e-mail: sonya@sezampro.rs