MELAS syndrome, cardiomyopathy, rhabdomyolysis, and autism associated with the A3260G mitochondrial DNA mutation

► Wide phenotypic heterogeneity exists with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. ► We expand the phenotype of MELAS syndrome associated with the 3260A > G mutation to include cardiomyopathy, exercise-induced hearing loss, exercise-induced rhabdomyolysis, and autism. ► This phenotypic variability is not race-specific, as previously hypothesized.