The buildup of which amino acids is associated with Maple syrup urine disease?

• A. Leucine, isoleucine, and valine
• B. Phenylalanine, tyrosine, and methionine
• C. Threonine, leucine, and cysteine
• D. Arginine, lysine, and histidine

Answer: (A)

The correct answer is associated with the accumulation of specific branched-chain amino acids due to a deficiency in the enzymes responsible for their metabolism. In Maple Syrup Urine Disease (MSUD), individuals are unable to properly degrade leucine, isoleucine, and valine, which are branched-chain amino acids. This metabolic disorder results from a deficiency in the branched-chain alpha-keto acid dehydrogenase complex, leading to elevated levels of these amino acids in the blood and urine.

The unique characteristic of maple syrup urine disease is reflected in the strong, sweet odor of the urine, reminiscent of maple syrup, caused by these accumulating amino acids. By identifying leucine, isoleucine, and valine as the problematic amino acids in MSUD, it becomes clear why this option is the correct association with the disease. The management of MSUD typically involves dietary restrictions to limit the intake of these amino acids and prevent their toxic accumulation, which is critical for effective treatment and management of the condition.