We have studied five children with mitochondrial myopathy manifesting within or soon after the first year of life. Muscle biopsies showed ragged-red fibers and decreasedrespiratory chain activity. All five patients had a severe decrease (2 to 34% of normal) in the amount of muscle mitochondrial DNA (mtDNA). The depletion of mtDNA correlated with absence of mtDNA-encoded translation products and with loss of cytochrome c oxidase enzyme activity in individual muscle fibers. This mitochondrial myopathy of childhoodillustrates one phenotypic expression of a novel pathogenetic mechanism in mitochondrial diseases the specific depletion of mtDNA in affected tissues.
|Number of pages||9|
|Publication status||Published - 1992|
ASJC Scopus subject areas
- Arts and Humanities (miscellaneous)
- Clinical Neurology