title: VSX1 gene analysis in keratoconus.
abstract: OBJECTIVE
  To screen the visual system homeobox 1 (VSX1) gene in keratoconus patients.
  
  
  METHODS
  The enntire coding region of VSX1, including intron-exon boundaries were amplified in keratoconus cases (n=50) and controls (n=50). All sequences were analyzed against the ensemble sequence (ENSG00000100987) for VXS1.
  
  
  RESULTS
  Sequencing analysis showed four alterations (p.A182A, p.R217H, p.P237P, and g.25059612C>T) in VSX1 of which g.25059612C>T (in intron 2) was found to be novel. Of these four, p.A182A and p.P237P were present in both cases as well as controls while p.R217H and g.25059612C>T were limited to cases only. All these changes were non-pathogenic.
  
  
  CONCLUSIONS
  In our study no pathogenic VSX1 mutation was identified. The role of VSX1 in the pathogenesis of keratoconus is still controversial. VSX1 mutations are responsible for a very small fraction of all observed keratoconus cases. The absence of pathogenic mutations in VSX1 in our patients indicates that other genetic loci like 13q32 as suggested by a recent study may be involved in the pathogenesis of this disorder.
authors.affiliation: Laboratory For Molecular Reproduction and Genetics, Department of Anatomy, Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Tanwar
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.forename: Bhagabat
authors.initials: B
authors.lastname: Nayak
authors.forename: Dhananjay
authors.initials: D
authors.lastname: Pathak
authors.forename: Namrata
authors.initials: N
authors.lastname: Sharma
authors.forename: Jeewan S
authors.initials: JS
authors.lastname: Titiyal
authors.forename: Rima
authors.initials: R
authors.lastname: Dada
mesh_terms: D000293:Adolescent; D000328:Adult; D019943:Amino Acid Substitution / Q000235:genetics; D001483:Base Sequence; D002648:Child; D003062:Codon / Q000235:genetics; D004252:DNA Mutational Analysis; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007438:Introns / Q000235:genetics; D007640:Keratoconus / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D010641:Phenotype; D055815:Young Adult
chemical_list: D003062:Codon; D005136:Eye Proteins; D018398:Homeodomain Proteins; C491583:VSX1 protein, human