title: Visual Pathways in Humans With Ephrin-B1 Deficiency Associated With the Cranio-Fronto-Nasal Syndrome.
abstract: OBJECTIVE
  Numerous animal studies demonstrated the importance of components of the ephrin/Eph system for correct visual system development. Analogous investigations in humans are entirely missing. Here, we examined the visual system in humans with ephrin-B1 deficiency, which is x-linked and associated with the cranio-fronto-nasal syndrome (CFNS) in heterozygous females.
  
  
  METHODS
  For one male hemizygous for ephrin-B1 deficiency and three affected heterozygous females with molecular-genetically confirmed mutations, the integrity of the partial decussation of the optic nerves was assessed with visual evoked potentials (VEPs) and compared with albinotic, achiasmic, and control participants with healthy vision. Further, retinal morphology and function and the gross-retinotopic representation of the primary visual cortex were examined with spectral-domain optical coherence tomography (SD-OCT), ERG, and multifocal (mf) VEPs for the male participant and part of the carriers.
  
  
  RESULTS
  Strabismus and lack of stereovision was evident in the male and two of the females. Other characteristics of the visual system organization and function were normal: (1) retina: SD-OCT and funduscopy indicated normal foveal and optic nerve head morphology. Electroretinograms indicated normal retinal function, (2) optic chiasm: conventional (c)VEP showed no evidence for misrouting and mfVEPs were only suggestive of, if any, very minor local misrouting, and (3) visual cortex: mfVEP characteristics indicated normal retinotopic gross-representations of the contralateral visual hemifield in each hemisphere.
  
  
  CONCLUSIONS
  While ephrin-B1 deficiency leads to abnormal visual pathways in mice, it leaves the human visual system, apart from deficits in binocular vision, largely normal. We presume that other components of the ephrin-system can substitute the lack of ephrin-B1 in humans.
authors.affiliation: Department of Ophthalmology Otto-von-Guericke-University, Magdeburg, Germany 2Center for Behavioural Brain Sciences, Magdeburg, Germany.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Hoffmann
authors.affiliation: Department of Ophthalmology Otto-von-Guericke-University, Magdeburg, Germany.
authors.forename: Hagen
authors.initials: H
authors.lastname: Thieme
authors.affiliation: Department of Ophthalmology Otto-von-Guericke-University, Magdeburg, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Liedecke
authors.affiliation: Department of Ophthalmology Otto-von-Guericke-University, Magdeburg, Germany.
authors.forename: Synke
authors.initials: S
authors.lastname: Meltendorf
authors.affiliation: Institute for Human Genetics, Otto-von-Guericke-University, Magdeburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Zenker
authors.affiliation: Institute for Human Genetics, Otto-von-Guericke-University, Magdeburg, Germany.
authors.forename: Ilse
authors.initials: I
authors.lastname: Wieland
mesh_terms: D000328:Adult; D000818:Animals; D019465:Craniofacial Abnormalities / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D004247:DNA / Q000235:genetics*; D004252:DNA Mutational Analysis; D036387:Ephrin-B1 / Q000172:deficiency / Q000235:genetics*; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D009154:Mutation; D013577:Syndrome; D041623:Tomography, Optical Coherence; D014795:Visual Pathways / Q000473:pathology / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D036387:Ephrin-B1; D004247:DNA