Mitochondrial myopathy is a type of myopathy

Myopathy

In medicine, a myopathy is a muscular disease in which the muscle fibers do not function for any one of many reasons, resulting in muscular weakness. "Myopathy" simply means muscle disease...

 associated with mitochondrial disease

Mitochondrial disease

Mitochondrial diseases are a group of disorders caused by dysfunctional mitochondria, the organelles that are the "powerhouses" of the cell. Mitochondria are found in every cell of the human body except red blood cells...

. On biopsy, the muscle tissue of patients with this disease usually demonstrate "ragged red" muscle fibers. These ragged-red fibers contain mild accumulations of glycogen and neutral lipids, and may show an increased reactivity for succinate dehydrogenase and a decreased reactivity for cytochrome c oxidase

Cytochrome c oxidase

The enzyme cytochrome c oxidase or Complex IV is a large transmembrane protein complex found in bacteria and the mitochondrion.It is the last enzyme in the respiratory electron transport chain of mitochondria located in the mitochondrial membrane...

. Inheritance is maternal (non-Mendelian extranuclear). There are several subcategories of mitochondrial myopathies.

Treatment

Although no cure currently exists, there is hope in treatment for this class of hereditary diseases with the use of an embryotic mitochondrial transplant

Protofection

Protofection is a term that refers to the transfection of foreign mitochondrial DNA to replace the original energy generators within cells. As mitochondria are damaged with age, this would be a method of rejuvenating them to original states....

.

Signs and symptoms

Signs and symptoms include:

• Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like syndrome (MELAS)
  • Varying degrees of cognitive impairment and dementia
  • Lactic acidosis
    Lactic acidosis
    Lactic acidosis is a physiological condition characterized by low pH in body tissues and blood accompanied by the buildup of lactate especially D-lactate, and is considered a distinct form of metabolic acidosis. The condition typically occurs when cells receive too little oxygen , for example...
    
    
  • Stroke
    Stroke
    A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
    
    s
  • Transient ischemic attack
    Transient ischemic attack
    A transient ischemic attack is a transient episode of neurologic dysfunction caused by ischemia – either focal brain, spinal cord or retinal – without acute infarction...
    
    s
  • Hearing loss
  • Weight loss

• Myoclonic epilepsy and ragged-red fibers (MERRF)
  • Progressive myoclonic epilepsy
  • Clumps of diseased mitochondria accumulate in muscle fibers and appear as "ragged-red fibers" when muscle is stained with modified Gömöri trichrome stain
    Gomori trichrome stain
    Gömöri trichrome stain is a stain used on muscle tissue.It can be used to test for certain forms of mitochondrial myopathy.It is named for George Gömöri, who developed it in 1950.-External links:...
    
    
  • Short stature

• Kearns-Sayre syndrome
  Kearns-Sayre syndrome
  Kearns–Sayre syndrome also known as oculocraniosomatic disease or Oculocraniosomatic neuromuscular disease with ragged red fibers is a mitochondrial myopathy with a typical onset before 20 years of age...
  
   (KSS)
  • External ophthalmoplegia
  • Cardiac conduction defects
  • Sensorineural hearing loss
    Sensorineural hearing loss
    Sensorineural hearing loss is a type of hearing loss in which the root cause lies in the vestibulocochlear nerve , the inner ear, or central processing centers of the brain....
    
    

• Chronic progressive external ophthalmoplegia
  Chronic progressive external ophthalmoplegia
  Chronic progressive external ophthalmoplegia , also known as progressive external ophthalmoplegia , is a type of eye movement disorder. It is often the only feature of mitochondrial disease, in which case the term CPEO may be given as the diagnosis...
  
   (CPEO)
  • Progressive ophthalmoparesis
    Ophthalmoparesis
    Ophthalmoparesis or ophthalmoplegia refers to paralysis of one or more extraocular muscles which are responsible for eye movements. It is a physical finding in certain neurologic illnesses.-Classification:...
    
    
  • Symptomatic overlap with other mitochondrial myopathies