This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': 'Most common genentic enzyme defect in urea cycle is \nSelect and explain. \nA. Arginase, B. Arginosuccunate lyase, C. Ornithine transcarbomylase, D. Carbomoyl phosphate synthase I', 'role': 'user'}, {'content': 'Answer: A \nExplanation: OTC combines carbamyl phosphate with ornithine to make citrulline which is subsequently processed tourea (see: cycle diagram). Along with CPSI and NAGS deficiency, OTCdeficiency is the most severe of theurea cycle disorders. Patients with complete OTC deficiency rapidly develop hyperammonemia in the newborn period Ref-Harpers illustrated biochemistry 30/e p583', 'role': 'assistant'}]