(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)
Pronounced: My–toe-con-dree-al My-op-a-thee
Mitochondrial myopathies decrease the ability of nerves and muscles. Weakness and uncoordinated movement may result.
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Mitochondrial myopathies are a group of diseases. Each disease has different symptoms. Some may be mild while other are life-threatening. However, the diseases are all caused by a problem with the mitochondria.
Mitochondria are tiny structures found in almost all cells. It is their job to provide energy to these cells. Mitochondrial myopathies can interfere with many different bodily functions. It tends to have the greatest impact on structures that are very active such as the muscles and nerves.
This condition is caused by a mutation in a specific gene.
Having a family member with the mutated gene increases the risk of mitochondrial myopathies.
Mitochondrial myopathies can cause a range of symptoms. Symptoms by specific condition include:
|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|
Other general symptoms include:
Your doctor will ask about your symptoms and medical history. A physical exam will be done. You will also be asked about any family history of the disease.
Tests may include the following:
- 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
There is no specific treatment for these diseases. Instead, treatment will focus on managing the symptoms. Treatment options include the following:
Supplements may help make energy in the cells. These may include:
Work with your doctor on the doses of these supplements.
Therapy may be used to strengthen muscles and improve mobility. Some may need devices like braces, walkers , or wheelchairs to help them get around.
Muscle weakness in the throat may make talking or swallowing difficult. Speech therapy may help strengthen the muscles or work around the weakness.
Respiratory therapy will help make sure you are breathing properly. It may involve some training techniques for respiratory muscles. It can include pressurized air treatment or the use of a ventilator.
Medicines may be needed for symptoms such as seizures or pain.
There are no known guidelines to prevent this condition.
Last reviewed December 2012 by Mike Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.