title: X-linked infantile periodic alternating nystagmus.
abstract: OBJECTIVE
  To describe the clinical and electrophysiological characterization of four family members from three generations who have X-linked infantile periodic alternating nystagmus (XIPAN).
  
  
  METHODS
  Complete clinical ophthalmological evaluation, pedigree analysis, electroretinograms (ERG), eye movement recordings (EMR), color vision, and fundus photography were performed on all subjects.
  
  
  RESULTS
  Three males in two generations and one female were examined. Clinical examinations showed a jerk/pendular nystagmus with a latent component, strabismus, and a significant refractive error in the three affected males, while the female had only myopic astigmatism. ERG, color contrast, and fundus examinations were normal in all four family members. All four family members showed EMR abnormalities with infantile jerk/dual jerk and pendular nystagmus waveforms. The female had nystagmus present on EMR only and all patients showed (a)periodicity to their nystagmus.
  
  
  CONCLUSIONS
  In this family with no other congenital visual sensory system disease, affected males had obvious periodic alternating nystagmus, strabismus, and refractive errors, while the female had clinically "silent" periodic nystagmus that is probably a marker for the carrier state.
authors: Department of Ophthalmology, Pittsburgh Eye and Ear Institute, The University of Pittsburgh Medical Center, Children's Hospital of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15213, U.S.A. Richard.hertle@chp.edu
authors: Richard W
authors: RW
authors: Hertle
authors: Dongsheng
authors: D
authors: Yang
authors: Kristopher
authors: K
authors: Kelly
authors: Vanessa M
authors: VM
authors: Hill
authors: Joan
authors: J
authors: Atkin
authors: Allison
authors: A
authors: Seward
mesh_terms: D000328:Adult; D000368:Aged; D002648:Child; D041321:Chromosomes, Human, X / Q000235:genetics*; D003867:Depth Perception / Q000502:physiology; D004596:Electroretinography; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D040181:Genetic Diseases, X-Linked / Q000235:genetics*; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000151:congenital / Q000235:genetics* / Q000473:pathology; D010375:Pedigree; D014792:Visual Acuity