Abstract
Purpose::
To investigate the possibility of visual system homeobox 1 (VSXI) as potential susceptibility candidate gene for Korean patients with keratoconus, we performed mutation screening of the VSXI gene.
Methods::
Total genomic DNA was extracted from blood samples of 111 unrelated patients with keratoconus visited the Department of Ophthalmology at the Catholic University Medical Center. Polymerase chain reaction - direct sequencing were used to screen genetic variations in whole coding region of the VSXI. Eighty five subjects without ocular diseases were selected from the general population as the normal control.
Results::
In this study, we found one heterozygous missense mutation, G160V (GGC>GTC) in exon 2, one heterozygous synonymous substitution, A182A in exon 3, and no mutation in exon 1, 4 and 5. In exon 2, G160V was identified in 11 unrelated patients of Keratoconus (6.3%), and was a novel missense mutation. This mutation was not found in control individuals. Two introgenic variations (IVS3+23G>A and IVS3+84 T>A) are detected. Among them, A182A and IVS3+23G>A were also observed in the control individuals, but do not differ significantly between cases and controls.
Conclusions::
In this study, we found a novel G160V mutation and three already-described changes, A182A, IVS3+23G>A and IVS3+84 T>A. Our data is the first report of heterozygous missense mutation, G160V of VSXI gene in Korean patients with keratoconus, and it might account for as much as 6.3% of keratoconus patients.
Keywords: keratoconus • genetics • gene screening