Mondo Description Myopathic mitochondrial DNA (mtDNA) depletion syndrome is one of the main forms of mtDNA depletion syndrome that displays a broad phenotypic spectrum but that is most often characterized by hypotonia, proximal muscle weakness, facial and bulbar weakness and failure to thrive.

Uniprot Description A disorder due to mitochondrial dysfunction characterized by childhood onset of muscle weakness associated with depletion of mtDNA in skeletal muscle. There is wide clinical variability; some patients have onset in infancy and show a rapidly progressive course with early death due to respiratory failure, whereas others have later onset of a slowly progressive myopathy.