Amino Acid & Protein Metabolism · NEET PG Preparation Biochemistry
A 7-day-old neonate presents with poor feeding, vomiting, and a maple syrup-like odor to the urine. Laboratory evaluation reveals severe metabolic ke…
Practice question from Amino Acid & Protein Metabolism (NEET PG Preparation Biochemistry), with the correct answer and a step-by-step solution.
easy · MCQ · Q-E4F6B3
A 7-day-old neonate presents with poor feeding, vomiting, and a maple syrup-like odor to the urine. Laboratory evaluation reveals severe metabolic ketoacidosis. Which of the following enzyme deficiencies is responsible for this condition?
- A.Phenylalanine hydroxylase
- B.Branched-chain alpha-keto acid dehydrogenase complexCorrect answer
- C.Homogentisate 1,2-dioxygenase
- D.Cystathionine beta-synthase
Solution
Maple syrup urine disease (MSUD) is caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex, which impairs the degradation of the branched-chain amino acids (leucine, isoleucine, and valine). This leads to an accumulation of these amino acids and their corresponding alpha-keto acids, causing a characteristic maple syrup odor in the urine and severe neurological and metabolic derangements.
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