In particular, maple syrup urine disease (MSUD), known as an aminoacidopathy, is one of the categorized IEMs caused by a deficiency of the mitochondrial enzyme called the branched-chain ketoacid dehydrogenase (BCKD) complex, resulting from mutations in the genes that encode complex BCKD subunits including E1α, E1β, E2, and E3 [4]. This evidence concerns the gene BCKDHB and maple syrup urine disease.