Keratoconus--no association with the transforming growth factor beta-induced gene in a cohort of American patients.
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.
Udar
Nitin
N
Jules Stein Eye Institute, School of Medicine, University of California-Los Angeles, 100 Stein Plaza, Los Angeles, CA 90095, USA.
Kenney
M Cristina
MC
Chalukya
Meenal
M
Anderson
Tara
T
Morales
Liezel
L
Brown
Donald
D
Nesburn
Anthony
A
Small
Kent
K
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
D004247:DNA; D016326:Extracellular Matrix Proteins; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein