A metabolic failure in the oxidative decarboxylation of BCAAs caused by mutations in any of the BCKDC components (BCKDHA, BCKDHB, DLD, or DBT genes) results in maple syrup urine disease (MSUD), or branched-chain ketoaciduria (OMIM: 248600) [4,7], with elevations of BCAAs in plasma, α-ketoacids in urine, and alloisoleucine in plasma, the pathognomonic marker of the disease. This evidence concerns the gene BCKDHB and maple syrup urine disease.