Autosomal recessive cardiomyopathy or ophthalmoplegia

**Definition:** 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.

**Exclusions:** - Secondary myopathies - Myasthenia gravis or certain specified neuromuscular junction disorders