α-Lipoic acid is a cofactor of three mitochondrial enzymes (PDH, α-ketoglutarate dehydrogenase and branched chain ketoacid decarboxylase) and was first tried as a treatment for PDH deficiency nearly 25 years ago (Byrd et al., 1989). This evidence concerns the gene PDP1 and hyperinsulinemic hypoglycemia, familial, 4.