The genetic variation in drug metabolism pathway that results in severe toxicity of fluorouracil is:: (A) CYP2C9, (B) Dihydropyrimidine dehydrogenase, (C) Thiopurine-S methyltransferase, (D) CYP2D6
Answer is B. Genetic variation in drug metabolism pathway dihydropyrimidine dehydrogenase results in severe toxicity of capecitabine, fluorouracil. Ref: Harrison, Edition-18, Page-42.