ETFDH and multiple acyl-CoA dehydrogenase deficiency: Multiple acyl-CoA dehydrogenase deficiency results from a defect of electron transport from FAD-containing CoA dehydrogenases to CoQ10 in the mitochondrial electron transport chain; this in turn is due to mutations in one of the three genes, two of which encode the alpha- and beta-subunits of the electron transfer flavoprotein (ETFA, OMIM: 608053; ETFB OMIM: 130410), while the third encodes ETF ubiquinone oxidoreductase (ETFDH OMIM 231675).