title: Clinical characteristics of rod and cone photoreceptor dystrophies in patients with mutations in the C8orf37 gene.
abstract: OBJECTIVE
  To provide the clinical features in patients with retinal disease caused by C8orf37 gene mutations.
  
  
  METHODS
  Eight patients--four diagnosed with retinitis pigmentosa (RP) and four with cone-rod dystrophy (CRD), carrying causal C8orf37 mutations--were clinically evaluated, including extensive medical history taking, slit-lamp biomicroscopy, ophthalmoscopy, kinetic perimetry, electroretinography (ERG), spectral-domain optical coherence tomography (SD-OCT), autofluorescence (AF) imaging, and fundus photography.
  
  
  RESULTS
  In families A and D, respectively, one and three patients showed a classic RP phenotype with night blindness followed by concentric loss of visual field. Severe visual loss to light perception occurred early in the course of the disease. The symptoms initiated during infancy (family A) or adolescence (family D). Ophthalmoscopy revealed macular atrophy, bone spicules, attenuated vessels, and waxy pale optic discs. SD-OCT showed profound photoreceptor degeneration and AF demonstrated atrophy of the retinal pigment epithelium (RPE). ERG responses were nonrecordable in these patients. In families B and C, the patients were diagnosed with CRD. Initial symptoms were photophobia or loss of visual acuity and occurred during infancy (family B) or adolescence (family C). Ophthalmoscopy and AF revealed profound macular RPE atrophy and SD-OCT demonstrated macular photoreceptor degeneration. ERG responses were severely reduced in a cone-rod pattern or were nonrecordable. Interestingly, both patients in family B demonstrated polydactyly.
  
  
  CONCLUSIONS
  Mutations in C8orf37 give rise to an early or adolescent-onset autosomal recessive CRD or RP phenotype with early macular atrophy. The occurrence of postaxial polydactyly in one family suggests a syndromic phenotype, which may indicate C8orf37 has a ciliary function.
authors.affiliation: Department of Ophthalmology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Ramon A C
authors.initials: RA
authors.lastname: van Huet
authors.forename: Alejandro
authors.initials: A
authors.lastname: Estrada-Cuzcano
authors.forename: Eyal
authors.initials: E
authors.lastname: Banin
authors.forename: Ygal
authors.initials: Y
authors.lastname: Rotenstreich
authors.forename: Stephanie
authors.initials: S
authors.lastname: Hipp
authors.forename: Susanne
authors.initials: S
authors.lastname: Kohl
authors.forename: Carel B
authors.initials: CB
authors.lastname: Hoyng
authors.forename: Anneke I
authors.initials: AI
authors.lastname: den Hollander
authors.forename: Rob W J
authors.initials: RW
authors.lastname: Collin
authors.forename: B Jeroen
authors.initials: BJ
authors.lastname: Klevering
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004596:Electroretinography; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D010641:Phenotype; D011506:Proteins / Q000235:genetics*; D012174:Retinitis Pigmentosa / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult
chemical_list: D011506:Proteins; C570604:CFAP418 protein, human
keywords: C8orf37; clinical characteristics; cone–rod dystrophy; retinitis pigmentosa