This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
Maple syrup urine disease is due to 
Select and explain. 
A. a-ketoacid decarboxylase, B. Transaminase, C. Isomerase, D. Mutase
A: a-ketoacid decarboxylase
Answer: A: a-ketoacid decarboxylase 
Explanation: Maple syrup urine disease is also known as Branched chain ketonuria. The basic biochemical deformity is deficient decarboxylation of branched-chain keto acid. This is due to the deficiency of alpha-ketoacid decarboxylase.Ref: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 230