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GTR Home > Conditions/Phenotypes > Juvenile myopathy, encephalopathy, lactic acidosis AND stroke

Summary

MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) is a multisystem disorder with protean manifestations. The vast majority of affected individuals develop signs and symptoms of MELAS between ages two and 40 years. Common clinical manifestations include stroke-like episodes, encephalopathy with seizures and/or dementia, muscle weakness and exercise intolerance, normal early psychomotor development, recurrent headaches, recurrent vomiting, hearing impairment, peripheral neuropathy, learning disability, and short stature. During the stroke-like episodes neuroimaging shows increased T2-weighted signal areas that do not correspond to the classic vascular distribution (hence the term "stroke-like"). Lactic acidemia is very common and muscle biopsies typically show ragged red fibers. [from GeneReviews]

Genes See tests for all associated and related genes

  • Also known as: COI, MTCO1, COX1
    Summary: mitochondrially encoded cytochrome c oxidase I

  • Also known as: COII, MTCO2, COX2
    Summary: mitochondrially encoded cytochrome c oxidase II

  • Also known as: COIII, MTCO3, COX3
    Summary: mitochondrially encoded cytochrome c oxidase III

  • Also known as: MTCYB, CYTB
    Summary: mitochondrially encoded cytochrome b

  • Also known as: MTND1, ND1
    Summary: mitochondrially encoded NADH dehydrogenase 1

  • Also known as: MTND5, ND5
    Summary: mitochondrially encoded NADH dehydrogenase 5

  • Also known as: MTND6, ND6
    Summary: mitochondrially encoded NADH dehydrogenase 6

  • Also known as: MTTC, TRNC
    Summary: mitochondrially encoded tRNA cysteine

  • Also known as: , TRNF
    Summary: mitochondrially encoded tRNA phenylalanine

  • Also known as: MTTK, TRNK
    Summary: mitochondrially encoded tRNA lysine

  • Also known as: MTTL1, TRNL1
    Summary: mitochondrially encoded tRNA leucine 1 (UUA/G)

  • Also known as: MTTQ, TRNQ
    Summary: mitochondrially encoded tRNA glutamine

  • Also known as: MTTS1, TRNS1
    Summary: mitochondrially encoded tRNA serine 1 (UCN)

  • Also known as: MTTS2, TRNS2
    Summary: mitochondrially encoded tRNA serine 2 (AGU/C)

  • Also known as: MTTV, TRNV
    Summary: mitochondrially encoded tRNA valine

  • Also known as: MTTW, TRNW
    Summary: mitochondrially encoded tRNA tryptophan

Clinical features

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