title: Investigation of VSX1 sequence variants in South Indian patients with sporadic cases of keratoconus.
abstract: BACKGROUND
  The involvement of VSX1 gene for the genetic basis of keratoconus is unclear and controversial. The genetic screening of VSX1 from different ethnic populations can enlighten this subject. The aim of the present study is to investigate the role of VSX1 gene in patients with sporadic cases of keratoconus from South India.
  
  
  METHODS
  The VSX1 gene coding regions, including exon-intron boundaries were screened by direct sequencing analysis in 117 sporadic cases of keratoconus. The identified variations were also analyzed in 108 ethnic matched healthy blood donors.
  
  
  RESULTS
  In the VSX1 gene screening, no pathogenic mutation was identified, whereas we could find the presence of four reported single nucleotide polymorphisms; c.546A>G (rs12480307), c.627+23G>A (rs6138482), c.627+84T>A (rs56157240) and c.504-24C>T (IVS3-24C). These variations were observed in similar frequency between cases and controls.
  
  
  CONCLUSIONS
  The lack of VSX1 pathogenic variations in a large number of unrelated sporadic keratoconus patients tend to omit its role, and corroborate the involvement of other genetic, environmental or behavioural factors in the development of this complex disorder.
authors.affiliation: Department of Genetics, Dr. G. Venkataswamy Eye Research Institute, Aravind Medical Research Foundation, Aravind Eye Hospital, Madurai, Tamil Nadu, India.
authors.forename: Anshuman
authors.initials: A
authors.lastname: Verma
authors.forename: Manoranjan
authors.initials: M
authors.lastname: Das
authors.forename: Muthiah
authors.initials: M
authors.lastname: Srinivasan
authors.forename: Namperumalsamy V
authors.initials: NV
authors.lastname: Prajna
authors.forename: Periasamy
authors.initials: P
authors.lastname: Sundaresan
mesh_terms: D016022:Case-Control Studies; D005136:Eye Proteins / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007194:India; D007640:Keratoconus / Q000235:genetics*; D009154:Mutation; D016133:Polymerase Chain Reaction
chemical_list: D005136:Eye Proteins; D018398:Homeodomain Proteins; C491583:VSX1 protein, human