View source for Mitochondrial myopathy

== Overview ==

Mitochondrial myopathy refers to a group of neuromuscular diseases caused by damage to the [[Mitochondria|mitochondria]], small energy-producing structures that serve as the cells' "power plants." Nerve cells in the brain and muscles require a great deal of energy, and thus appear to be particularly damaged when mitochondrial dysfunction occurs. This article delves into the intricacies of these conditions, their causes, symptoms, diagnosis, and treatment options.

[[Image:Detail-49679.jpg|thumb|center|A microscopic view of a cell highlighting the mitochondria.|class=only_on_mobile]]
[[Image:Detail-49680.jpg|thumb|center|A microscopic view of a cell highlighting the mitochondria.|class=only_on_desktop]]

== Causes ==

The primary cause of mitochondrial myopathy is genetic mutation, either in the nuclear DNA (nDNA) or mitochondrial DNA (mtDNA). These mutations lead to impaired mitochondrial function, particularly affecting the mitochondria's ability to produce energy. The mutations can be inherited from one or both parents, or they can occur spontaneously at conception.

== Types ==

Mitochondrial myopathies include a variety of syndromes, such as [[Kearns-Sayre Syndrome|Kearns-Sayre syndrome]], [[MELAS|MELAS syndrome]], and [[Leigh's Disease|Leigh's disease]]. Each of these conditions has unique symptoms and prognoses, but all are characterized by mitochondrial dysfunction.

=== Kearns-Sayre Syndrome ===

Kearns-Sayre Syndrome (KSS) is a mitochondrial DNA deletion disorder, typically presenting before the age of 20. It is characterized by progressive external ophthalmoplegia (PEO), pigmentary retinopathy, and cardiac conduction defects.

=== MELAS Syndrome ===

MELAS syndrome, or Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes, is a condition that affects many of the body's systems, particularly the brain and nervous system (encephalo-) and muscles (myopathy). The signs and symptoms of this disorder most often appear in childhood following a period of normal development.

=== Leigh's Disease ===

Leigh's disease is a severe neurological disorder that typically arises in the first year of life. This condition is characterized by progressive loss of mental and movement abilities (psychomotor regression) and typically results in death within a couple of years, usually due to respiratory failure.

== Symptoms ==

The symptoms of mitochondrial myopathies can vary greatly in severity and onset, depending on the type of disease and the specific genetic mutation. Common symptoms include muscle weakness or exercise intolerance, heart failure or rhythm disturbances, dementia, movement disorders, stroke-like episodes, deafness, blindness, droopy eyelids, limited mobility of the eyes, vomiting, and seizures.

== Diagnosis ==

Diagnosing mitochondrial myopathy involves a thorough clinical evaluation, detailed patient history, and a variety of specialized tests. These tests may include a muscle biopsy to detect ragged-red fibers indicating mitochondrial accumulation. Genetic testing can confirm a diagnosis in some cases.

== Treatment ==

There is currently no cure for mitochondrial myopathies. Treatment is symptomatic and supportive, and may include physical therapy, respiratory therapy, and the use of mobility aids. Vitamins and other supplements may be used in an attempt to improve mitochondrial function, although their effectiveness is not yet proven in controlled studies.

== Prognosis ==

The prognosis for individuals with mitochondrial myopathy varies greatly depending on the type and severity of the condition, the age of onset, and the specific symptoms. Some individuals may lead relatively normal lives, while others may face significant disability.

== See Also ==

* [[Mitochondrial Disease|Mitochondrial Diseases]]
* [[Genetic Disorder|Genetic Disorders]]
* [[Muscular Dystrophy|Muscular Dystrophies]]

[[Category:Neuromuscular disorders]]
[[Category:Genetic disorders]]
[[Category:Mitochondrial diseases]]