18bp Fragment Insertion/Deletion Polymorphism of Vascular Endothelial Growth Factor (VEGF) Gene with Diabetes Mellitus Type 2 and Diabetic Retinopathy Patients of Quetta, Balochistan, Pakistan

Background: An important candidate gene for diabetic retinopathy (DR) is vascular endothelial growth factor (VEGF). The VEGF gene is extremely polymorphic. The 18 base pairs (bp) segment (I/D) polymorphism at -2549 position of the promoter region is of great importance. Aim: The present study aimed to identify VEGF (I/D) polymorphism in DM and DR patients. Materials and Methods: This cross section study involved 100 healthy control subjects, 100 diabetes mellitus (DM) subjects and 100 DR subjects. Blood samples were collected after informed consent of study subjects, DNA extraction was performed using inorganic method, VEGF gene promoter region that was confirmed using 2% agarose gel. Polymerase Chain Reaction (PCR) was used to identify (I/D) polymorphism of 18 bp fragment at position -2549, DNA Sequencing was done commercially to confirm the presence of 18bp I/D polymorphism. The allele (I/D) and genotypes (DD, I/D, II) frequencies of VEGF gene were compared among all the study subjects. Results: The frequency of DD genotype in DR was 52% while in DM was 40% and in control was 2%. The significant differences (p<0.05) were observed when genotypes were compared among control and DM, DM and DR, Control and DR. The significant differences (p<0.05) were observed in Control and DM Control and DR, DM and DR at 95% CI. Conclusion: These findings suggest that the DD genotype is possible risk factor for development and progression of retinopathy as compared to uncomplicated subject II genotype in local population.