BCAT1 and type 2 diabetes mellitus: BCAT1 single nucleotide polymorphisms were identified as associated with type 2 diabetes from a genome-wide association scans (Rampersaud et al., 2007), and in the skeletal muscle of patients with type 2 diabetes, the expression of the gene encoding the first step enzyme involved in BCAA metabolism (BCAT2) is reduced, and the patient’s branched-chain amino acid metabolism is inhibited.