Mitochondrial Myopathy, Lethal, Infantile, also known as lethal infantile mitochondrial myopathy, is related to cox deficiency, benign infantile mitochondrial myopathy and mitochondrial disease. An important gene associated with Mitochondrial Myopathy, Lethal, Infantile is MT-TT (Mitochondrially Encoded TRNA-Thr (ACN)). Affiliated tissues include liver and lung, and related phenotypes are renal insufficiency and progressive external ophthalmoplegia