Specimen

4 mL (2 mL min.) Whole blood in 1 Lavender Top (EDTA) tube. Ship refrigerated. DO NOT FREEZE. Physician prescription is mandatory.

Usage

Detection of TPMT genetic variants by genotyping is recommended prior to commencing the treatment of patients with Thiopurine drugs such as Azathioprine, 6-Mercaptopurine and 6-Thioguanine for Acute Lymphoblastic Leukemia & autoimmune disorders like Crohn's disease & Rheumatoid arthritis.TPMT is an enzyme which converts these drugs in the body to an active form. Any genetic defect in this enzyme predisposes patients to a heightened risk of drug-induced bone marrow toxicity due to accumulation of unmetabolised drug. Approximately 0.3% of individuals lack TPMT activity while 11% show reduced activity (variants TPMT*2, 3A & 3C). 89% of people have normal activity (variant TPMT*1).