Association of single nucleotide polymorphisms (SNPs) of VEGF gene with diabetic retinopathy

Abstract

Abstract Purpose: Vascular endothelial growth factor (VEGF) has an important role in the development of diabetic retinopathy. High concentration of vitreous VEGF and elevated VEGF expression has been found in diabetic retinopathy. Single nucleotide polymorphisms (SNPs) of VEGF gene have been shown to influence expression of VEGF. We studied the association of VEGF SNPs with severity of diabetic retinopathy. Methods: The study population consisted of 129 diabetic (type 1 or type 2) patients with laser‐treated retinopathy, 99 diabetic patients with mild or no retinopathy and 524 non‐diabetic controls. SNPs were chosen on structural basis at three different haploblocks of the VEGF gene covering the whole VEGF gene and in addition, polymorphisms previously known to affect VEGF production were selected. VEGF SNPs rs699947, rs2010963, rs2146323, rs3025033 and rs3025039 were genotyped using the 5' nuclease assay for allelic discrimination (TaqMan). The allele and genotype frequencies were analyzed with chi‐square test in SPSS. Results: Duration of diabetes was similar in patients with laser‐treated retinopathy and in patients with mild or no retinopathy (mean 22.8 vs. 22.7 years, respectively), but the laser‐treated diabetic group had somewhat poorer glycemic control (9.2 vs. 8.4 %). The distribution of genotypes and the allele frequencies did not differ significantly between the diabetics and controls, between patients with laser‐treated retinopathy and patients with mild or no retinopathy, or between patients with proliferative retinopathy and patients with non‐proliferative retinopathy. Conclusions: In conclusion, these findings suggest that VEGF gene SNPs studied are not associated with the severity of diabetic retinopathy.