title: Detection of localized retinal dysfunction in a choroideremia carrier.
abstract: OBJECTIVE
  To investigate severe unilateral vision loss in a choroideremia carrier.
  
  
  METHODS
  Case report.
  
  
  METHODS
  Ocular examination, genetic testing, Humphrey visual fields, full-field and multifocal (mf) electroretinogram (ERG) tests were used to study a family with choroideremia.
  
  
  RESULTS
  In a carrier with unilateral central vision loss, mfERG showed severely reduced amplitudes which correlated with a band of retinal pigment epithelial and choroidal atrophy in the macula, a dense central scotoma on Humphrey visual fields testing, and decreased ERG amplitudes.
  
  
  CONCLUSIONS
  Multifocal ERG may be a sensitive tool to measure functional abnormalities in choroideremia carriers. Mosaic inactivation of the normal gene may cause expression of the mutation with severe vision loss in choroideremia carriers.
authors.affiliation: University of California School of Medicine, San Francisco, California 94143-0730, USA.
authors.forename: Marsha C
authors.initials: MC
authors.lastname: Cheung
authors.forename: George C
authors.initials: GC
authors.lastname: Nune
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Kerry E
authors.initials: KE
authors.lastname: McTaggart
authors.forename: Ian M
authors.initials: IM
authors.lastname: MacDonald
authors.forename: Jacque L
authors.initials: JL
authors.lastname: Duncan
mesh_terms: D000368:Aged; D015794:Choroideremia / Q000235:genetics / Q000503:physiopathology*; D004596:Electroretinography; D005260:Female; D006579:Heterozygote; D006801:Humans; D012160:Retina / Q000503:physiopathology; D012164:Retinal Diseases / Q000235:genetics / Q000503:physiopathology*; D012607:Scotoma / Q000235:genetics / Q000503:physiopathology; D014792:Visual Acuity; D014794:Visual Fields