Multiple acyl-CoA Dehydrogenase Deficiency or Glutaric aciduria type II (GAII) is a recessive disorder classically associated to defect in one of the two electron flavoprotein transporters implicated in electron transfer from acyl-CoA dehydrogenases to the respiratory chain: (1) ElectronTransfer Flavoprotein (ETF, coded by ETFA and ETFB genes) and (2) ETF-ubiQuinone Oxidoreductase (ETFQO, coded by ETFDH gene) [102]. The gene discussed is ETFDH; the disease is hyperinsulinemic hypoglycemia, familial, 4.