title: Autosomal recessive bestrophinopathy associated with angle-closure glaucoma.
abstract: OBJECTIVE
  Abnormalities in the BEST1 gene have recently been recognised as causing autosomal recessive bestrophinopathy (ARB). ARB has been noted to have a variable phenotypic presentation, distinct from that of autosomal dominant Best vitelliform macular dystrophy (BVMD). Both conditions are associated with deposits in the retina, a reduced or absent electro-oculography (EOG) light rise, and the risk of developing angle-closure glaucoma. Herein, we describe the clinical and genetic characteristics of a young male diagnosed with ARB associated with angle-closure glaucoma resulting from a novel homozygous mutation in BEST1.
  
  
  METHODS
  All research involved in this case adhered to the tenets of the Declaration of Helsinki. The proband underwent slitlamp examination, retinal autofluorescence imaging and optical coherence tomography after presenting with deteriorating vision. The findings prompted genetic testing with bi-directional DNA sequencing of coding and flanking intronic regions of BEST1. The proband's family members were subsequently screened.
  
  
  RESULTS
  A provisional diagnosis of ARB was made based on the findings of subretinal and schitic lesions on fundoscopy and retinal imaging, together with abnormal EOG and electroretinography. Genetic testing identified a novel homozygous mutation in BEST1, c.636+1 G>A. Family members were found to carry one copy of the mutation and had no clinical or electrophysiological evidence of disease. The proband was additionally diagnosed with angle-closure glaucoma requiring topical therapy, peripheral iridotomies and phacoemulsification.
  
  
  CONCLUSIONS
  Phenotypic overlap, reduced penetrance, variable expressivity and the ongoing discovery of new forms of bestrophinopathies add to the difficulty in distinguishing these retinal diseases. All patients diagnosed with ARB or BVMD should be examined for narrow angles and glaucoma, given their frequent association with these conditions.
authors.affiliation: Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, WA, 6009, Australia, claire.crowley86@gmail.com.
authors.forename: C
authors.initials: C
authors.lastname: Crowley
authors.forename: R
authors.initials: R
authors.lastname: Paterson
authors.forename: T
authors.initials: T
authors.lastname: Lamey
authors.forename: T
authors.initials: T
authors.lastname: McLaren
authors.forename: J
authors.initials: J
authors.lastname: De Roach
authors.forename: E
authors.initials: E
authors.lastname: Chelva
authors.forename: J
authors.initials: J
authors.lastname: Khan
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use; D000075002:Bestrophins; D018118:Chloride Channels / Q000235:genetics*; D003131:Combined Modality Therapy; D004585:Electrooculography; D004596:Electroretinography; D015785:Eye Diseases, Hereditary / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D005136:Eye Proteins / Q000235:genetics*; D005451:Fluorescein Angiography; D005808:Genes, Recessive; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D006801:Humans; D007429:Intraocular Pressure; D032801:Iridectomy; D008297:Male; D009154:Mutation; D018918:Phacoemulsification; D012164:Retinal Diseases / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology
chemical_list: D000959:Antihypertensive Agents; C113133:BEST1 protein, human; D000075002:Bestrophins; D018118:Chloride Channels; D005136:Eye Proteins