Mitochondrial Myopathy

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Mitochondrial Myopathy is a mitochondrial disease causing significant muscular problems is referred to as mitochondrial myopathy, while a mitochondrial disease that causes significant neurological and muscular problems is termed as mitochondrial encephalomyopathy. Organs such as brain, skeletal muscles and cardiac muscles have very high energy requirements, so they are disproportionately affected by mitochondrial dysfunction. Recent studies have reported two mtDNA mutations in mitochondrial myopathy patients. Specific mutations in certain mitochondrial genes (MTTK gene, MIEF2 gene; separate studies) may lead to imbalanced mitochondrial dynamics and a combined respiratory chain enzyme defect in skeletal muscle, leading to mitochondrial myopathy.

Symptoms: Muscle weakness, muscle atrophy, and exhaustion caused by physical exertion (exercise intolerance) are some of the main symptoms of mitochondrial myopathy. Muscle weakness begins with eye muscles and eyelids progressing to ptosis, paralysis of eye movements, blindness (retinitis pigmentosa, optic atrophy), cataracts, cardiomyopathy; liver failure (uncommon except in babies with mtDNA depletion syndrome), fatty liver, Fanconi’s syndrome (loss of essential metabolites in urine), difficulty swallowing, vomiting, feeling of being full, chronic diarrhea, symptoms of intestinal obstruction; diabetes. In addition to these, patients with mitochondrial encephalomyopathy might experience seizures, spasms, developmental delays, deafness, dementia, stroke (often before age 40), visual system defects, poor balance, problems with peripheral nerves. Mitochondrial myopathies can be managed by approaches such as physical therapy, speech therapy or respiratory therapy. While these cannot reverse the disease course, they may significantly improve the patients’ mobility, functioning, and strength. Additionally, inclusion of dietary supplements has also shown to help in certain cases. These supplements aim at bypassing the defective mitochondria and are based on three natural substances involved in ATP production in our cells- creatine, L- carnitine and coQ10.

Scarpelli et al. (2018) Bartsakoulia et al. (2018) Ahuja, A (2018)