Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Mitochondrial Myopathies


Michael Rubin

, MDCM, New York Presbyterian Hospital-Cornell Medical Center

Last full review/revision Jul 2020| Content last modified Jul 2020
Click here for the Professional Version

Mitochondrial myopathies are muscle disorders inherited through faulty genes in the mitochondria or in the nuclear genes that control mitochondrial function. The muscles and organs such as the brain, nerves, and retinas are affected.

Mitochondria Cells Often thought of as the smallest unit of a living organism, a cell is made up of many even smaller parts, each with its own function. Human cells vary in size, but all are quite small. Even... read more Cells are the energy factories of cells and carry some of their own genes. When mitochondria stop working properly, less and less energy is generated within the cells. This may lead to cell injury or even cell death, and body systems, often including the muscles, will not function properly. Mitochondrial myopathies can be inherited through faulty genes within the mitochondria themselves or through genes within the cell nucleus.

Mitochondrial myopathies can cause increasing weakness in one or a few muscle groups, such as the eye muscles (ophthalmoplegia) and often affect many other organs, such as the heart, intestines, or brain. Infants whose muscles are affected are weak and have severely reduced muscle tone (hypotonia, or "floppiness"). Depending on which organs are affected, complications may include deafness or hearing loss Hearing Impairment in Children Hearing loss in newborns most commonly results from cytomegalovirus infection or genetic defects and in older children results from ear infections or earwax. If children do not respond to sounds... read more Hearing Impairment in Children , seizures Seizures in Children Seizures are a periodic disturbance of the brain’s electrical activity, resulting in some degree of temporary brain dysfunction. When older infants or young children have seizures, they often... read more , or stroke-like episodes Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction) and symptoms that... read more . One mitochondrial myopathy is called Kearns-Sayre syndrome. It causes problems with the eyes, muscles, and heart.

Treatment of Mitochondrial Myopathies

No specific treatment is available for mitochondrial myopathy, but various drugs and treatments are used to manage symptoms and complications.

More Information

The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Test your knowledge
Colic is the term used for a pattern of intense, excessive crying and fussing that occurs for no apparent reason in some infants. It typically begins within the first month of life. At what age does colic typically end?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID