MT-ATP6 and Leigh syndrome: MT-ATP6–related mitochondrial disease has been associated with various phenotypes, including NARP (neuropathy, ataxia, and retinitis pigmentosa) syndrome, Leigh syndrome (LS), Charcot–Marie–Tooth (CMT) disease, spinocerebellar ataxia (SCA), encephalopathy, peripheral neuropathy, proximal myopathy, cardiomyopathy, dystonia.