title: Are mitochondrial DNA deletions causative in chronic progressive external ophthalmoplegia patients?
abstract: Twenty-one patients with long standing unexplained ptosis (3), chronic progressive external ophthalmoplegia (CPEO, 16) or Kearns-Sayre syndrome (KSS, 2) were studied for the presence of mitochondrial DNA (mtDNA) deletions and the major disease-associated mtDNA point mutations with the aim of correlating mitochondrial genetic abnormalities with pathogenesis in these patients. Only 52% were found to have a deletion; of these, 82% harboured the 'common deletion'. Two of 2 KSS patients and 9 of 16 CPEO patients were deletion positive. None of the 3 patients with bilateral ptosis only had a deletion. Of those patients with ragged red fibres (RRF) on histology, 69% had a deletion. No disease associated mtDNA point mutation was observed with the exception of the nucleotide (nt) 11084 A-G mutation associated with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) in a patient also harbouring the common deletion. The role of deletions in CPEO patients is discussed.
authors.affiliation: Clinical Neuroscience Centre, St Vincent's Hospital, Fitzroy, Victoria 3065, Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Jean-Francois
authors.forename: S
authors.initials: S
authors.lastname: Collins
authors.forename: N
authors.initials: N
authors.lastname: Kotsimbos
authors.forename: X
authors.initials: X
authors.lastname: Dennett
authors.forename: E
authors.initials: E
authors.lastname: Byrne