Cardiomyopathy and kidney disease in a patient with maternally inherited diabetes and deafness caused by the 3243A>G mutation of mitochondrial DNA

Cardiomyopathy is a manifestation of mitochondrial cytopathies, but rarely constitutes the dominant feature, especially in adults. We report the case of a 59-year-old male with a personal and maternal history of diabetes and deafness, who presented with cardiomyopathy and kidney disease. We diagnosed the patient as having a mitochondrial cytopathy resulting from the 3243A>G mutation on the tRNALeu(UUR) gene in the mitochondrial DNA. The family history, broad spectrum of clinical manifestations and fluctuant clinical course provided clues to the diagnosis. We discuss the possible mechanisms underlying the phenotypic variability and fluctuant clinical course of mitochondrial disorders and the potential usefulness of coenzyme Q10 and L-carnitine in 3243A>G mutation patients.