ICD-11

Mitochondrial myopathies are heterogeneous group of disorders caused by dysfunction of mitochondrial oxidative phosphorylation and can be classified according to the associated biochemical, genetic defects (in the mitochondrial DNA or in nuclear encoded proteins) or clinical phenotype. Exclude: defects of mitochondrial respiratory chain, Kearns-Sayre syndrome, myoclonic epilepsy with ragged red fibres (MERRF)

Autosomal recessive cardiomyopathy and ophthalmoplegia is a childhood-onset disease characterised by progressive external ophthalmoplegia, mild facial and proximal limb weakness, and severe cardiomyopathy. Muscle biopsies show ragged-red and cytochrome C oxidase-negative fibres; the activities of several complexes in the electron-transport chain are decreased. The combination of progressive external ophthalmoplegia, cardiomyopathy, and multiple mtDNA deletions is thought to be due to a defect of communication between the nuclear and mitochondrial genomes.