A Study of VEGF Gene Polymorphism in Egyptian Patients with Diabetic Retinopathy

There are subgroups of patients with diabetes mellitus (DM) in whom diabetic retinopathy (DR) does not develop despite poor long-term control of their disease, while others exercising fairly good control, develop retinopathy. So, we aimed to investigate the association of DR with -2578 polymorphism of the vascular endothelial growth factor (VEGF) gene, which has been reported to be associated with increased VEGF production, in Egyptian diabetic patients.

This is a case control study in which 148 diabetic patients were enrolled. Among them, 44 subjects had proliferative diabetic retinopathy (PDR), 30 had non-proliferative diabetic retinopathy (NPDR), and 74 individuals without retinopathy served as controls. A single nucleotide polymorphism (SNP) of the VEGF gene, a C→A transversion at -2578 (the C/A polymorphism), was investigated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

We found a higher frequency of the polymorphic genotype in both the NPDR (66.7%) and PDR (72.7%) groups compared to the wild C/C genotype (33.3% in NPDR and 27.3% in PDR), but with no statistically significant difference from the control group. Significant association of the progression of DR to the polymorphic genotype was achieved at diabetes duration more than 20 years.

Despite of the higher frequency of both the polymorphic genotype and the A allele in cases with DR compared to the control group, there might be no significant association between the VEGF gene polymorphism and DR per se, unless it is longstanding.