mitochondrial myopathies
Definition: Muscular defects of the mitochondrial respiratory chain. Defects in the mitochondrial respiratory chain impair energy production and almost invariably involve skeletal muscle, causing exercise intolerance, cramps, recurrent myoglobinuria, or fixed weakness, which often affects extraocular muscles and results in droopy eyelids (ptosis) and progressive external ophthalmoplegia.
Types
defects in nuclear DNA
-* coenzyme Q10 deficiency
- mutations in genes controlling mitochondrial DNA abundance and structure
- POLG
- TK2
- MPV17
- Barth syndrome
- X-linked recessive mitochondrial myopathy/cardiopathy
- decreased amount and altered structure of cardiolipin, the main phospholipid of the inner mitochondrial membrane
- mutations in protein-coding genes of mitochondrial DNA
- mutations in tRNA genes
See also
mitochondrial encephalomyopathy with lactic acidosis and stroke (MELAS)
inflammatory myopathies associated with mtDNA deletions
References
Dimauro S. Mitochondrial myopathies. Curr Opin Rheumatol. 2006 Nov;18(6):636-41. PMID: 17053512