
Mitochondrial myopathy

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 was believed to be maternal (non-Mendelian extranuclear). It is now known that certain nuclear DNA deletions can also cause mitochondrial myopathy such as the OPA1 gene deletion. There are several subcategories of mitochondrial myopathies.
Signs and symptoms.
Signs and symptoms include (for each of the following causes):
Cause.
Zidovudine, an HIV medication can cause red ragged fiber myopathy.
Diagnosis.
Muscle biopsy: ragged red fibers in Gömöri trichrome stain.
Treatment.
Although no cure currently exists, there is hope in treatment for this class of hereditary diseases with the use of an embryonic mitochondrial transplant.