title: Keratoconus--no association with the transforming growth factor beta-induced gene in a cohort of American patients.
abstract: OBJECTIVE
  Keratoconus is a noninflammatory, corneal thinning disorder leading to mixed myopic and irregular astigmatism and implicated as a major reason for cornea transplantations in the Western world. Genetic factors have been suggested as a cause of keratoconus. The levels of transforming growth factor beta-induced (TGFBI) protein have been reported to be altered in keratoconus tissues. Mutations in this gene are responsible for causing various corneal dystrophies. Given this strong evidence of the involvement of this gene in corneal dystrophies, we investigated possible mutations within this gene in 15 probands of families with keratoconus.
  
  
  METHODS
  All patients and control individuals had complete ophthalmological examination by a corneal specialist to determine their affectation status. The entire transcript of the TGFBI gene was analyzed by direct sequencing from patient DNA.
  
  
  RESULTS
  We found 8 sequence variations within the gene, none of which was protein-altering changes. These changes were also observed in control individuals, and 4 are previously known polymorphisms.
  
  
  CONCLUSIONS
  We concluded that the TGFBI gene is not responsible for causing keratoconus in these patients.
authors.affiliation: Jules Stein Eye Institute, School of Medicine, University of California-Los Angeles, 100 Stein Plaza, Los Angeles, CA 90095, USA.
authors.forename: Nitin
authors.initials: N
authors.lastname: Udar
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Kenney
authors.forename: Meenal
authors.initials: M
authors.lastname: Chalukya
authors.forename: Tara
authors.initials: T
authors.lastname: Anderson
authors.forename: Liezel
authors.initials: L
authors.lastname: Morales
authors.forename: Donald
authors.initials: D
authors.lastname: Brown
authors.forename: Anthony
authors.initials: A
authors.lastname: Nesburn
authors.forename: Kent
authors.initials: K
authors.lastname: Small
mesh_terms: D019943:Amino Acid Substitution; D016022:Case-Control Studies; D015331:Cohort Studies; D004247:DNA / Q000235:genetics; D005091:Exons / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D006801:Humans; D007438:Introns / Q000235:genetics; D007640:Keratoconus / Q000235:genetics*; D009154:Mutation; D011110:Polymorphism, Genetic; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein
chemical_list: D004247:DNA; D016326:Extracellular Matrix Proteins; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein