MT-TL2 and External ophthalmoplegia: Several other point mutations in the MT-TL2 gene have been implicated in mitochondrial diseases, including CPEO, MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke syndrome), and other mitochondrial myopathies including isolated dilated cardiomyopathy [17]–[21],[15],[22],[16].