title: VSX1 gene and keratoconus: genetic analysis in Korean patients.
abstract: OBJECTIVE
  The visual system homeobox 1 (VSX1) gene variants have recently been shown to be associated with keratoconus. To replicate this finding, we performed a genetic analysis of the VSX1 gene in a Korean case-control sample.
  
  
  METHODS
  Patients with keratoconus and healthy control subjects were recruited from Seoul National University Hospital. A diagnosis of keratoconus was made based on clinical examinations and the presence of characteristic topographic features. For all patients and controls, the whole coding region and the exon-intron junctions of the VSX1 gene were analyzed by direct sequencing.
  
  
  RESULTS
  Fifty-three patients with keratoconus and 100 healthy volunteers were included. We observed 2 novel missense substitutions (Leu17Val and Val199Leu) and 1 previously reported substitution (Gly160Val) in 6 of the 53 affected probands. Because these substitutions have been identified in unaffected individuals, they were not considered to be pathogenic. No intragenic polymorphism was associated with a significantly increased risk of keratoconus.
  
  
  CONCLUSIONS
  We cannot confirm the previously reported association of the VSX1 gene variants with keratoconus. Our results suggest that the VSX1 gene and its mutations with amino acid changes do not play a major role in the pathogenesis of keratoconus.
authors.affiliation: Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Jeoung
authors.forename: Mee Kum
authors.initials: MK
authors.lastname: Kim
authors.forename: Sung Sup
authors.initials: SS
authors.lastname: Park
authors.forename: Sung Yeun
authors.initials: SY
authors.lastname: Kim
authors.forename: Hyun Soo
authors.initials: HS
authors.lastname: Ko
authors.forename: Won Ryang
authors.initials: WR
authors.lastname: Wee
authors.forename: Jin Hak
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D019781:Corneal Topography; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D005136:Eye Proteins / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007640:Keratoconus / Q000175:diagnosis / Q000235:genetics*; D020125:Mutation, Missense; D016133:Polymerase Chain Reaction; D012029:Refraction, Ocular / Q000502:physiology; D056910:Republic of Korea; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D017931:DNA Primers; D005136:Eye Proteins; D018398:Homeodomain Proteins; C491583:VSX1 protein, human