title: Enhanced S-cone function with preserved rod function: a new clinical phenotype.
abstract: OBJECTIVE
  To describe the clinical findings and genetic analysis in two brothers having a novel retinal disease characterized by an enhanced S-cone phenotype with normal rod function.
  
  
  METHODS
  Both patients underwent complete ophthalmologic examinations, including fundus photography, electroretinography (ERG), fluorescein angiography and optical coherence tomography (OCT). Mutation analysis of the following candidate genes was performed: nuclear receptor subfamily 2 group E member 3 (NR2E3), neural retina leucine zipper (NRL), nuclear receptor subfamily 1 group D member 1 (NR1D1), and thyroid hormone receptor beta (THRB).
  
  
  RESULTS
  Spectral photopic ERG responses demonstrated enhanced S-cone function in both patients. Their scotopic b-wave ERG amplitude responses, however, were within normal limits. Their scotopic a-wave amplitude responses were within the lower limit of normal. The a- and b-wave latencies were normal for one sibling and on the upper limit of normal for the other. Peripheral retinal findings were normal. OCT showed flattening of the macular curvature and thinning of the photoreceptor layer. Mutation analysis of NR2E3, NRL, NR1D1, and THRB genes was negative.
  
  
  CONCLUSIONS
  We describe what appears to be a previously unidentified familial retinal phenotype with enhanced S-cone function and well preserved rod system function in contrast to the severely reduced rod function seen in the enhanced S-cone syndrome (ESCS). Genetic analysis of candidate genes did not reveal the cause of disease. We postulate that the disease might be caused by mutation of another, as yet unidentified gene, which encodes a protein that functions as a negative inhibitor of rod and S-cone development.
authors: Department of Ophthalmology, The Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel.
authors: Michael
authors: M
authors: Kinori
authors: Eran
authors: E
authors: Pras
authors: Andrew
authors: A
authors: Kolker
authors: Gili
authors: G
authors: Ferman-Attar
authors: Iris
authors: I
authors: Moroz
authors: Joseph
authors: J
authors: Moisseiev
authors: Dikla
authors: D
authors: Bandah-Rozenfeld
authors: Liliana
authors: L
authors: Mizrahi-Meissonnier
authors: Dror
authors: D
authors: Sharon
authors: Ygal
authors: Y
authors: Rotenstreich
mesh_terms: D000328:Adult; D018912:Arabs; D003241:Consanguinity; D004252:DNA Mutational Analysis; D004596:Electroretinography; D005136:Eye Proteins / Q000235:genetics; D005451:Fluorescein Angiography; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology* / Q000502:physiology; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D035781:Siblings; D041623:Tomography, Optical Coherence; D014786:Vision Disorders / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics / Q000503:physiopathology*
chemical_list: D005136:Eye Proteins