Biochemistry The following enzyme defect causes acute intermittent porphyria A Uroporphyrinogen III synthase B Uroporphyrinogen decarboxylase C Hydroxymethylbilane synthase D Protoporphyrinogen oxidase 💡 Explanation The following enzyme defect causes acute intermittent porphyria ✓ Correct Answer: C. Hydroxymethylbilane synthase