b-hydroxybutyric aciduria is associated with deficiency of: (A) Orotidylic acid decarboxylase, (B) Orotate phosphoribosyl transferase, (C) PRPP Synthase, (D) Dihydropyrimidine dehydrogenase
Answer is D. b-hydroxybutyric aciduria, a pyrimidine catabolism disorder due to total or paial deficiency of the enzyme dihydropyrimidine dehydrogenase. This disorder can develop toxicity to 5-fluorouracil, also a substrate for this dehydrogenase enzyme. Reference: Harpers illustrated biochemistry 30th edition