Which amino acids accumulate in Maple Syrup Disease?

Maple Syrup Disease (MSUD) is a metabolic disorder characterized by an inability to properly break down certain branched-chain amino acids (BCAAs). The amino acids that primarily accumulate in this condition are valine, leucine, and isoleucine. This disorder results from a deficiency of the branched-chain alpha-keto acid dehydrogenase complex, which is essential for the catabolism of these three amino acids.

As a result of the enzyme deficiency, the byproducts of valine, leucine, and isoleucine metabolism build up in the bloodstream, leading to the characteristic symptoms associated with Maple Syrup Disease, such as a sweet smell in the urine, neurological impairment, and metabolic crisis if untreated. This accumulation is the direct cause of the clinical manifestations observed in individuals with the disorder.

The other answer choices include amino acids that are not linked to this particular metabolic defect, which is why they do not apply to Maple Syrup Disease. For instance, phenylalanine, tyrosine, and tryptophan are involved in different metabolic pathways and are related more to phenylketonuria (PKU) rather than MSUD. Similarly, isoleucine, methionine, and alan