Genetic disorders of BCAA metabolism produce amino acidopathies and various forms of
organic aciduria with severe clinical consequences. A metabolic block in the oxidative
decarboxylation of BCAA caused by mutations in the mitochondrial branched-chain α-keto
acid dehydrogenase complex (BCKDC) results in Maple Syrup Urine Disease (MSUD) or
branched-chain ketoaciduria. There are presently five known clinical phenotypes for MSUD,
ie, classic, intermediate, intermittent, thiamin-responsive, and dihydrolipoamide …