Lack of association of the VEGF gene promoter (-634 G→C and -460C→T) polymorphism and the risk of advanced retinopathy of prematurity

Background Recently, it has been reported that genetic polymorphism (-634 G -> C and -460 C -> T) in the promoter region of the vascular endothelial growth factor (VEGF) gene can influence the progression of retinopathy of prematurity (ROP). In order to evaluate its general applicability as a screening procedure in clinics and to replicate the above result, we have undertaken the following study. Methods We have analyzed a cohort of 61 patients with advanced ROP (stage 4 and 5) along with 61 normal controls for the VEGF gene promoter polymorphism. For this purpose, blood samples were collected from each patient and leukocyte DNA was isolated. Genomic DNA was amplified by the polymerase chain reaction (PCR) method with two pairs of primers designed to amplify separately the promoter region (containing -634 G -> C and -460 C -> T polymorphism) of the VEGF gene. The amplified product was subjected to restriction enzyme digestion. The base change in the restriction site was further confirmed by a BigDye terminator cycle sequencing of the amplified product. Results Our analysis suggests that there is no significant difference in allelic frequency of the VEGF gene between normal subjects and patients with advanced ROP in our cohort. Conclusions Our results do not support the association of the VEGF gene promoter polymorphism and the risk of advanced ROP. In order to adapt this method for the identification of high-risk infants in clinics in the future, a large-scale study involving a mixed ethnically diverse population is much needed.