title: Clinical and Oculographic Findings of X-linked Congenital Nystagmus in Three Korean Families.
abstract: OBJECTIVE
  Congenital nystagmus (CN) is an ocular oscillation that usually manifests during early infancy. Typical features of CN include bilateral, conjugate, uniplanar, and usually horizontal eye movements, a null position, increased oscillation during fixation, and decreased amplitude during convergence. Our purposes were description and analysis of clinical and oculomotor findings of patients with X-linked familial CN.
  
  
  METHODS
  We describe the clinical and oculographic features of five patients from three families with X-linked CN. Three-dimensional video-oculography disclosed various patterns of CN and variable degrees of gaze-holding deficits and visual impairments.
  
  
  RESULTS
  The features of CN varied even in patients from the same family. Head tilt, strabismus, reversal of optokinetic nystagmus, and impairments of the vestibulo-ocular reflex, smooth pursuits, and saccades were frequent findings.
  
  
  CONCLUSIONS
  The intra- and interfamilial diversities imply that heredity plays a secondary role in determining the clinical phenotypes and waveforms of CN.
authors.affiliation: Department of Neurology, Seoul National University College of Medicine.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Oh
authors.forename: Byong-Soo
authors.initials: BS
authors.lastname: Shin
authors.forename: Ki-Young
authors.initials: KY
authors.lastname: Jeong
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Hwang
authors.forename: Ji Soo
authors.initials: JS
authors.lastname: Kim