The DBT gene is located on 1p21.2 chromosome, where it encodes a part of an enzyme complex (E2) of 482 amino acids. This inner mitochondrial enzyme complex called branched-chain alpha-keto acid dehydrogenase (BCKD) is involved in the normal breakdown of three amino acids: leucine, isoleucine, and valine. The breakdown of these amino acids produces molecules that can be used for energy.
Defects in the Dihydrolipoamide Branched-Chain Transacylase enzyme result in accumulation of the above-mentioned amino acids and their corresponding keto acids in the nervous system. This accumulation results in the development of Maple Syrup Urine Disease, characterized by seizures, developmental delay, and mental retardation.