Polyneuropathy as a multisystemic plus symptom in chronic progressive external ophthalmoplegia: Phenotypic differences in between singular deletions and multiple deletions of mito…

Chronic progressive external ophthalmoplegia (CPEO) is one of the most common manifestations in mitochondrial disorders. Besides manifestation with weakness of extraocular muscles and limb muscles other organs can be affected (CPEO plus) including peripheral nerve system. On molecular levels deletions of mitochondrial DNA (mtDNA) are frequently identified in CPEO. One can distinguish in between CPEO with multiple deletions that are caused by nuclear defects in several genes (so called defects of intergenomic communication) and singular deletions of mtDNA that occur mainly sporadically. In mitochondrial disorders…