thiopurine s-methyltransferase

thiopurine s-methyltransferase

(thī″ŏ-pūr′ēn″es′meth″ĭl-trans′fĕr-ās″),

TPMT

An enzyme that metabolizes and inactivates thiopurines (such as the drugs azathioprine and mercaptopurine). People with a genetic deficiency in TPMT have severe bone marrow suppression when they take thiopurines to manage diseases such as rheumatoid arthritis or inflammatory bowel disease.