This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'All of the following are excreted in urine in Maple syrup urine disease, EXCEPT: \nSelect and explain. \nA. Leucine, B. Isoleucine, C. Valine, D. None of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: As the name implies, the odor of urine in maple syrup urine disease (branched-chain ketonuria) suggests maple syrup or burnt sugar. The biochemical defect involves the -keto acid decarboxylase complex. Plasma and urinary levels of leucine, isoleucine, valine, -keto acids, and -hydroxy acids (reduced -keto acids) are elevated. Ref: Harper 28th edition, chapter 29.', 'role': 'assistant'}]