Distinct segregation of the pathogenic m.5667G > A mitochondrial tRNAAsn mutation in extraocular and skeletal muscle in chronic progressive external ophthalmoplegia

Chronic progressive external ophthalmoplegia (CPEO) is the most frequent mitochondrial myopathy [1], which is characterised by a slowly progressive paresis of extraocular muscles leading to ptosis and restriction of eye movements with subsequent strabism and – less frequently – diplopia. CPEO is caused by mutations either in the mitochondrial (mt) or the nuclear genome both resulting in a perturbance of mitochondrial oxidative phosphorylation. Sporadically occurring single large-scale mtDNA rearrangements (deletions or duplications) as well as spora dically or maternally inherited mtDNA point mutations are attributed to primary mtDNA mutagenesis, whereas secondary mtDNA rearrangements are caused by nuclear gene mutations leading to multiple mtDNA deletions or depletions.
Source: Neuromuscular Disorders - Category: Neurology Authors: Source Type: research