title: Recessive Stargardt disease phenocopying hydroxychloroquine retinopathy.
abstract: OBJECTIVE
  To describe a series of patients with Stargardt disease (STGD1) exhibiting a phenotype usually associated with hydroxychloroquine (HCQ) retinopathy on spectral domain-optical coherence tomography (SD-OCT).
  
  
  METHODS
  Observational case series from Columbia University Medical Center involving eight patients with genetically-confirmed STGD1. Patients selected for the study presented no history of HCQ use. Horizontal macular SD-OCT scans and accompanying 488-nm autofluorescence (AF) images, color fundus photographs, and full-field electroretinograms were analyzed.
  
  
  RESULTS
  All study patients exhibited an abrupt thinning of the parafoveal region or disruption of the outer retinal layers on SD-OCT resembling the transient HCQ retinopathy phenotype. Funduscopy and AF imaging revealed variations of bull's eye maculopathy (BEM). Five patients exhibited local fleck-like deposits around the lesion. Genetic screening confirmed two disease-causing ABCA4 mutations in five patients and one mutation in three patients.
  
  
  CONCLUSIONS
  A transient SD-OCT phenotype ascribed to patients with HCQ retinopathy is associated with an early subtype of STGD1. This finding may also present with HCQ retinopathy-like BEM lesions on AF imaging and funduscopy. A possible phenotypic overlap is unsurprising, given certain shared mechanistic disease processes between the two conditions. A thorough work-up, including screening of genes that are causal in retinal dystrophies associated with foveal sparing, may prevent misdiagnosis of more ambiguous cases.
authors: Department of Ophthalmology, Columbia University, Eye Research Annex Rm 202, 160 Ft Washington Ave, New York, NY, 10032, USA.|Department of Ophthalmology, University of Tartu, Tartu, Estonia.
authors: Kalev
authors: K
authors: Nõupuu
authors: Department of Ophthalmology, Columbia University, Eye Research Annex Rm 202, 160 Ft Washington Ave, New York, NY, 10032, USA.
authors: Winston
authors: W
authors: Lee
authors: Department of Ophthalmology, Columbia University, Eye Research Annex Rm 202, 160 Ft Washington Ave, New York, NY, 10032, USA.
authors: Jana
authors: J
authors: Zernant
authors: Department of Ophthalmology, Columbia University, Eye Research Annex Rm 202, 160 Ft Washington Ave, New York, NY, 10032, USA.
authors: Vivienne C
authors: VC
authors: Greenstein
authors: Department of Ophthalmology, Columbia University, Eye Research Annex Rm 202, 160 Ft Washington Ave, New York, NY, 10032, USA.|Department of Pathology & Cell Biology, Columbia University, New York, NY, USA.
authors: Stephen
authors: S
authors: Tsang
authors: Department of Ophthalmology, Columbia University, Eye Research Annex Rm 202, 160 Ft Washington Ave, New York, NY, 10032, USA. rla22@cumc.columbia.edu.|Department of Pathology & Cell Biology, Columbia University, New York, NY, USA. rla22@cumc.columbia.edu.
authors: Rando
authors: R
authors: Allikmets
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000328:Adult; D000962:Antimalarials / Q000633:toxicity*; D002648:Child; D004596:Electroretinography; D005260:Female; D005808:Genes, Recessive; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D006886:Hydroxychloroquine / Q000633:toxicity*; D008268:Macular Degeneration / Q000151:congenital* / Q000175:diagnosis / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D012164:Retinal Diseases / Q000139:chemically induced / Q000175:diagnosis*; D012189:Retrospective Studies; D000080362:Stargardt Disease; D041623:Tomography, Optical Coherence; D055815:Young Adult
chemical_list: C056475:ABCA4 protein, human; D018528:ATP-Binding Cassette Transporters; D000962:Antimalarials; D006886:Hydroxychloroquine
keywords: ABCA4; Hydroxychloroquine toxicity; Phenocopy; Stargardt disease