PPM1K and Intellectual disability: Another two different genes were more recently described how members of the BCKD complex in MSUD: BCKDK gene (MIM # 614923) and PPM1K gene (MIM # 615135); defects of PPM1K may account for a subset of human MSUD; inactivating variants of BCKDK in humans are associated with BCAA deficiency, MSUD, autism, epilepsy, and intellectual disability [10].