Abstract
Purpose:
To determine the possibility of anti-oxidant related genes, peroxiredoxin 1, 2 and 6 (Prdx1, 2 and 6), Superoxide Dismutases 1, 2 and 3 (SOD 1, 2 and 3), and Glutathione S-transfease (GSTs; GSTP1, GSTT1, GSTM1) genes, as potential susceptibility candidate gene for Korean patients with Keratoconus, we investigated the association of the Prdx1, Prdx2, Prdx6, SOD1, SOD2, SOD3 variations and null genotype of GSTP1, GSTT1, GSTM1, in unrelated Korean patients with Keratoconus
Methods:
Genomic DNA was extracted from blood samples of unrelated Keratoconus patients, visited the Eye Center of Seoul St. Mary’s Hospital. To screen genetic variations in anti-oxidant related genes, we investigated using polymerase chain reaction and direct sequencing. Control individuals were selected from the general population without Keratoconus.
Results:
We analyzed twenty two polymorphic sites in promoter, intervening and exon regions of the Prdx 1, 2, 6 and SOD 1, 2, 3 genes and null genotype of GST genes. Among them, -657 g>c in promoter of Prdx1, IVS3-237a>g and rs1205171 (IVS3-227c>t) of Prdx2 and IVS1-1141 a>g of Prdx6 were significantly different between patient and control groups. Frequencies of g/g genotype in promoter of Prdx1 in keratoconus patients was significantly decreased compared with the control subjects (50.0% vs 69.3%, p=0.015) and c allele of keratoconus patients was significantly difference compared with control subjects (O.R. = 2.123). In Prdx2, genotypic and allelic distribution of IVS3-237a>g and rs1205171 were significantly different between keratoconus patients and controls; a/a genotype (p=0.001) and g allele (O.R. = 6.63) of IVS3-237a>g and c/c genotype (p=0.043, O.R. = 2.037) and c allele (p=0.037, O.R. = 1.597) of rs1205171, respectively. IVS1-1141 a>g of Prdx6 was significantly different between patient and control groups. The g allele (p = 0.001, O.R. = 7.44) was associated with a significantly increased risk of keratoconus in Korean patients. But there were no statistically significant differences in the allele and genotype frequencies of SODs and GSTs between keratoconus patients and controls.
Conclusions:
This is the first report of genetic variation screening of anti oxidant related genes in Korean keratoconus patients and our results showed an association between Keratoconus risk and variations of Prdx genes in Korean.