Studies from skeletal muscle pathology in patients with mitochondrial myopathy caused by other genetic aetiology found that apoptotic markers, including cytochrome c and Bcl-x, were localised in a granular distribution within the cytoplasm of either COX-negative fibres or ragged-red fibres, and DNA breaks, which are signs of activated apoptosis, were observed both in the myonuclear and mtDNA genome [151,152]. The gene discussed is COX5A; the disease is Mitochondrial myopathy.