Mitochondrial myopathies are types of myopathies associated with mitochondrial disease. On biopsy, the muscle tissue of patients with these diseases usually demonstrate "ragged red" muscle fibers. These ragged-red fibers contain mild accumulations of glycogen and neutral lipids, and may show an increased reactivity for succinate dehydrogenase and a decreased reactivity for cytochrome c oxidase. Inheritance is maternal (non-Mendelian extranuclear). There are several subcategories of mitochondrial myopathies.
^"Three-parent embryo formed in lab"(web). Scientists believe they have made a potential breakthrough in the treatment of serious disease by creating a human embryo with three separate parents. BBC News. 5 February 2008. Retrieved 2008-02-08.