Mitochondrial Myopathy

Living With

Dear Friends:

If you are reading this, it’s probably because you or a loved one has just received a very bewildering diagnosis: mitochondrial myopathy. What is a mitochondrial myopathy, and what does the term mean?

Richard Kelly with family
The Kelly family at the MDA Labor Day Telethon

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Clinical Trials

About clinical trials

A clinical trial is a test in humans of an experimental medication or therapy. Clinical trials are experiments, not treatments, and participation requires careful consideration.

Although it's possible to benefit from participating in a clinical trial, it's also possible that no benefit — or even harm — may occur. Keep your MDA clinic doctor informed about any clinical trial participation. (Note that MDA has no ability to influence who is chosen to participate in a clinical trial.)


With MDA’s support, scientists continue to make significant progress in their quest to fully understand and treat mitochondrial diseases.

Unique progress has been made in MNGIE, a disease in which a flaw in a gene in the nucleus indirectly causes a mitochondrial problem. MDA-funded researchers are experimenting with infusing donor stem cells into patients with MNGIE to restore normal metabolic conditions and halt damage to the mitochondria.

Medical Management

While mitochondrial myopathies and encephalomyopathies are relatively rare, some of their potential manifestations are common in the general population. Consequently, those complications (including heart problems, stroke, seizures, migraines, deafness and diabetes) have highly effective treatments (including medications, dietary modifications and lifestyle changes).


What causes mitochondrial diseases?

Mitochondrial diseases aren’t contagious, and they aren’t caused by anything a person does. They’re caused by mutations, or changes, in genes — the cells’ blueprints for making proteins.


None of the hallmark symptoms of mitochondrial disease — muscle weakness, exercise intolerance, hearing impairment, ataxia, seizures, learning disabilities, cataracts, heart defects, diabetes and stunted growth — are unique to mitochondrial disease. However, a combination of three or more of these symptoms in one person strongly points to mitochondrial disease, especially when the symptoms involve more than one organ system.

Types of Mitochondrial Myopathies

This page contains information about the nine most common mitochondrial myopathies and encephalomyopathies. They are: