Multiple acyl-CoA dehydrogenase deficiency, or glutaric aciduria type II, is an autosomal recessive disorder of fatty acid oxidation due to defects in electron transfer flavoprotein (ETF) encoded by ETFA and ETFB, or in electron transfer flavoprotein dehydrogenase (ETFDH) encoded by the ETFDH gene. The disease may present as a severe neonatal onset form and a mild late-onset form which is heterogeneous for the age at onset and clinical presentation. We describe two patients in their seventies, referred for a nonspecific myopathy, which resulted to manifest carriers of ETFDH gene mutation. Treatment with riboflavin and L-carnitine improved the clinical picture and the biochemical profile. This condition should be included in the differential diagnosis of myopathies even at an old age.
Keywords: ETFDH gene mutations; Fatty acid oxidation; Late-onset multiple acyl-CoA dehydrogenase deficiency (MADD); Myopathy; Riboflavin treatment.