title: Leber's hereditary optic neuropathy and vitamin B12 deficiency.
abstract: BACKGROUND
  Leber's hereditary optic neuropathy (LHON) is a maternally inherited optic neuropathy caused by mutations in mitochondrial DNA (mtDNA). It is also believed that several epigenetic factors have an influence on the development of LHON.
  
  
  METHODS
  A case series was observed.
  
  
  RESULTS
  Three patients who developed bilateral optic neuropathy are presented. All patients had a primary LHON mutation in their mtDNA, but also a subnormal vitamin B12 serum level at the time of presentation.
  
  
  CONCLUSIONS
  The clinical picture of optic neuropathy associated with vitamin B12 deficiency shows similarity to that of LHON. Both involve the nerve fibres of the papillomacular bundle. The present case reports suggest that optic neuropathy in patients carrying a primary LHON mtDNA mutation may be precipitated by vitamin B12 deficiency. Therefore, known carriers should take care to have an adequate dietary intake of vitamin B12 and malabsorption syndromes like those occurring in familial pernicious anaemia or after gastric surgery should be excluded.
authors.affiliation: Department of Ophthalmology, University Medical Centre Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands. j.w.r.pott@ohk.umcg.nl
authors.forename: Jan Willem R
authors.initials: JW
authors.lastname: Pott
authors.forename: Kwok H
authors.initials: KH
authors.lastname: Wong
mesh_terms: D000328:Adult; D000368:Aged; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D029242:Optic Atrophy, Hereditary, Leber / Q000097:blood / Q000150:complications*; D014805:Vitamin B 12 / Q000097:blood; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000150:complications*
chemical_list: D004272:DNA, Mitochondrial; D014805:Vitamin B 12