What condition might lead to increased levels of leucine, a branched-chain amino acid?

Increased levels of leucine are most notably associated with maple syrup urine disease, a metabolic disorder resulting from a deficiency in the branched-chain alpha-keto acid dehydrogenase complex. This complex is essential for the catabolism of branched-chain amino acids, specifically leucine, isoleucine, and valine. When this enzymatic pathway is disrupted, as in maple syrup urine disease, it leads to an accumulation of these amino acids in the blood and urine, with leucine being particularly elevated.

This condition is characterized by symptoms such as a distinctive sweet odor in the urine, neurological issues, and can lead to severe health complications if not treated promptly. Therefore, the direct relationship between the disorder and the accumulation of leucine makes it clear that this is the correct choice when discussing conditions that lead to increased levels of this specific branched-chain amino acid. Understanding this metabolic pathway is critical for diagnosing and managing maple syrup urine disease effectively.