(Kearns-Sayre Syndrome; Leigh’s Syndrome; Mitochondrial DNA Depletion Syndrome; Mitochondrial Encephalomyopathy, Lactic Acidosis and Strokelike Episodes; Myoclonic Epilepsy Associated With Ragged Red Fibers; Mitochondrial Neurogastrointestinal Encephalopathy; Neuropathy, Ataxia, and Retinitis Pigmentosa; Pearson’s Syndrome; Progressive External Ophthalmoplegia)
|Muscular and Nervous Systems|
|Mitochondrial myopathies decrease the ability of nerves and muscles. Weakness and uncoordinated movement may result.|
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|NAME OF CONDITION||AGE OF ONSET||DEFINING SYMPTOMS|
|Kearns-Sayre syndrome (KSS)||Before age 20||Salt and pepper pigmentation in eye, eye movement problems (PEO), heart and skeletal muscle dysfunction|
|Leigh’s syndrome||Infancy (can appear later)||Brain abnormalities that lead to muscle problems, seizures, uncoordinated muscle movement (ataxia), impaired vision and hearing, developmental delay and poor control over breathing|
|Mitochondrial DNA depletion syndrome||Infancy||Muscle weakness and liver failure, floppiness, feeding difficulties, and developmental delay|
|Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS)||Childhood to adulthood||Stroke-like episodes, migraine headaches, vomiting and seizures, muscle weakness, exercise intolerance, hearing loss, diabetes, short stature|
|Myoclonic epilepsy associated with ragged red fibers (MERRF)||Late childhood to adulthood||Myoclonus (jerky movements), seizures, muscle weakness, uncoordinated muscle movement (ataxia)|
|Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE)||Before age 20||Eye movement problems (PEO), drooping eyelid, limb weakness, digestive problems, peripheral neuropathy|
|Neuropathy, ataxia, and retinitis pigmentosa (NARP)||Early childhood to adulthood||Uncoordinated muscle movement (ataxia), degeneration of the retina in the eye leading to loss of vision|
|Pearson’s syndrome||Infancy||Causes severe anemia and pancreas problems, survivors usually develop KSS|
|Progressive external ophthalmoplegia (PEO)||Adulthood||Eye movement difficulty, and often symptoms of other mitochondrial diseases, but can be an independent syndrome|
- Muscle biopsy—to look for abnormal levels of mitochondria
- Blood test—to look for abnormal levels of certain enzymes and other substances
- Lumbar puncture (spinal tap) —to evaluate the fluid surrounding the brain and spinal cord
- Electromyography (EMG) and nerve conduction velocity (NCV)—to test nerve and muscle interaction
- Genetic test
- Eye exam
Muscular Dystrophy Association http://www.mda.org/
National Institute of Neurological Disorders and Stroke http://www.ninds.nih.gov/
Canadian Institute of Health Research http://www.cihr-irsc.gc.ca/
Muscle Dystrophy Canada http://www.muscle.ca/
Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice . 5th ed. Philadelphia, PA: Butterworth Heniemann Elsevier; 2008.
DiMauro S. Pathogenesis and treatment of mitochondrial myopathies: recent advances. Acta Myol. 2010;29(2):333-338.
Facts about mitochondrial myopathies. Muscular Dystrophy Association website. Available at: http://www.mda.org/publications/mitochondrial%5Fmyopathies.html . Accessed December 27, 2012.
Fauci A, Harrison TR. Harrison's Principles of Internal Medicine . 17th ed. New York, NY: McGraw-Hill; 2008.
Jacobs L, Wert GD, Geraedts J, de Coo I, Smeets H. The transmission of OXPHOS disease and methods to prevent this. Hum Reprod Update . 2006;12(2):119-136.
Metabolic myopathies. American College of Rheumatology website. Available at: http://www.rheumatology.org/public/factsheets/diseases%5Fand%5Fconditions/metabolicmyopathies.asp?aud=pat . Accessed December 27, 2012.
Mitochondrial myopathies. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Updated November 7, 2012. Accessed December 27, 2012.
Mitochondrial myopathy. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/mitochondrial%5Fmyopathy/mitochondrial%5Fmyopathy.htm . Accessed December 27, 2012.
- Reviewer: Mike Woods, MD
- Review Date: 12/2012 -
- Update Date: 12/27/2012 -