title: The characterization of retinal phenotype in a family with C1QTNF5-related late-onset retinal degeneration.
abstract: OBJECTIVE
  To describe the clinical, spectral-domain optical coherence tomography and electrophysiological features of C1QTNF5-associated late-onset retinal degeneration in a molecularly confirmed pedigree.
  
  
  METHODS
  Five members of a family participated, and affected individuals (n = 4) underwent detailed ophthalmologic evaluation including fundus autofluorescence and spectral-domain optical coherence tomography imaging and electroretinography. Electrooculography was performed in three individuals.
  
  
  RESULTS
  The visual acuity was initially normal and worsened with time. Anterior segment abnormalities included peripupillary iris atrophy and long anterior insertion of zonules. Peripapillary atrophy, drusenoid deposition, and scalloped sectorial chorioretinal atrophy were observed in all older individuals (n = 3). Fundus autofluorescence demonstrated hypofluorescent areas corresponding to regions of chorioretinal atrophy. The spectral-domain optical coherence tomography demonstrated multiple areas of retinal pigment epithelium-Bruch membrane separation with intervening homogeneous deposition that corresponded to the drusenoid lesions and areas of chorioretinal atrophy. Electrooculography was normal in one individual and showed abnormally low dark trough measures in older individuals (n = 2). Electroretinography was normal in early stages (n = 1), but showed marked abnormalities in the rod system (n = 3), which was predominantly inner retinal (n = 2) in late stages.
  
  
  CONCLUSIONS
  Late-onset retinal degeneration is a progressive degeneration, and anterior segment abnormalities present early. The widespread sub-retinal pigment epithelium deposition seen on spectral-domain optical coherence tomography in older individuals appears to be a characteristic in late stages. Electrooculography demonstrates abnormalities only in late stages of the disease.
authors.affiliation: Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
authors.forename: Ajoy
authors.initials: A
authors.lastname: Vincent
authors.forename: Francis L
authors.initials: FL
authors.lastname: Munier
authors.forename: Cynthia C
authors.initials: CC
authors.lastname: Vandenhoven
authors.forename: Tom
authors.initials: T
authors.lastname: Wright
authors.forename: Carol A
authors.initials: CA
authors.lastname: Westall
authors.forename: Elise
authors.initials: E
authors.lastname: Héon
mesh_terms: D000328:Adult; D000368:Aged; D003094:Collagen / Q000235:genetics*; D003317:Corneal Dystrophies, Hereditary / Q000175:diagnosis; D018450:Disease Progression; D004585:Electrooculography; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009896:Optic Atrophy / Q000175:diagnosis; D010375:Pedigree; D010641:Phenotype; D012160:Retina / Q000503:physiopathology; D012162:Retinal Degeneration / Q000175:diagnosis* / Q000235:genetics* / Q000503:physiopathology; D015593:Retinal Drusen / Q000175:diagnosis; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology
chemical_list: C487851:C1QTNF5 protein, human; D003094:Collagen