C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase gene: effect on methotrexate-related toxicity in adult acute lymphoblastic leukaemia.

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme involved in folate metabolism. Two polymorphisms, C677T and A1298C, were described leading to reduced enzyme activity. Methotrexate (MTX) is an antifolate agent of consolidation and maintenance therapy of acute lymphoblastic leukaemia (ALL).