<unk>  is a metabolic disorder caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex (BCKAD), leading to a buildup of the branched-chain amino acids (leucine, isoleucine, and valine) and their toxic by-products (ketoacids) in the blood and<unk> . The buildup of these BCAAS will lead to the<unk><unk>  odor that is associated with<unk> . The BCKAD complex begins by breaking down leucine, isoleucine, and valine through the use of branch-chain aminotransferase into their relevant α-ketoacids. The second step involves the conversion of α-ketoacids into acetoacetate, acetyl-CoA, and succinyl-CoA through oxidative decarboxylation of α-ketoacids. The BCKAD complex consists of four subunits designated E1α, E1β, E2, and E3. The E3 subunit is also a component of pyruvate dehydrogenase complex and oxoglutarate dehydrogenase complex.<unk>  can result from mutations in any of the genes that code for these enzyme subunits, E1α, E1β, E2, and E3. Mutations of these enzyme subunits will lead to the BCKAD complex unable to break down leucine, isoleucine, and valine. The levels of these branched chain amino acids will become elevated and lead to the symptoms associated with<unk> . Glutamate levels are maintained in the brain by BCAA metabolism functions and if not properly maintained can lead to neurological problems that are seen in<unk>  individuals. High levels of leucine has also been shown to affect water homeostasis within subcortical gray matter leading to cerebral edema, which occurs in<unk>  patients if left untreated.
Maple syrup urine disease
Urocanic aciduria
Alpha-aminoadipic and alpha-ketoadipic aciduria
Hawkinsinuria
3-Methylglutaconic aciduria
Homocystinuria
Alkaptonuria
2-Hydroxyglutaric aciduria