Neha Patil (Editor)

Mitochondrial myopathy

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Specialty
  
neurology

MeSH
  
D017240

ICD-10
  
G71.3

Mitochondrial myopathy

Mitochondrial myopathies are types of myopathies associated with mitochondrial disease. On biopsy, the muscle tissue of patients with these diseases 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. Inheritance is maternal (non-Mendelian extranuclear). There are several subcategories of mitochondrial myopathies.

Contents

Signs and symptoms

Signs and symptoms include (for each of the following causes):

  • Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like syndrome (MELAS)
  • Varying degrees of cognitive impairment and dementia
  • Lactic acidosis
  • Strokes
  • Transient ischemic attacks
  • 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
  • Short stature
  • Kearns-Sayre syndrome (KSS)
  • External ophthalmoplegia
  • Cardiac conduction defects
  • Sensorineural hearing loss
  • Chronic progressive external ophthalmoplegia (CPEO)
  • Progressive ophthalmoparesis
  • Symptomatic overlap with other mitochondrial myopathies
  • Treatment

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

    References

    Mitochondrial myopathy Wikipedia