MADD, which can cause cardiomyopathy [78], is either attributed to mutations in the genes coding for the mitochondrial electron transfer flavoprotein-ubiquinone oxidoreductase (ETFDH), electron transfer flavoprotein subunit alpha (ETFA), or electron transfer flavoprotein subunit beta (ETFB) (MIM #231680). Here, ETFDH is linked to cardiomyopathy.