Association between vascular endothelial growth factor + 936C/T gene polymorphism and age-related macular degeneration

Abstract

Background Vascular endothelial growth factor(VEGF) has been shown to be associated with the pathogenesis of age-related macular degeneration (AMD),therefore VEGF is a target for the treatment of wet AMD.However,the mechanism of VEGF in the pathogenesis of AMD is not clearly understood.Studying the correlation between VEGF gene polymorphism and AMD is becoming a new research hotspot,but relevant studies on Han Chinese have not been performed.Objective This study was to investigate the association between the VEGF +936C/T gene polymorphism and AMD in the Chinese population.Methods A pilot prospective and nonrandomized controlled trial was designed.This protocol complied with Declaration of Helsinki and was approved by the Ethic Committee of Chinese PLA Second Artillery General Hospital.Written informed consent was obtained from each subject prior to entering the study.Two hundred AMD patients and 200 age-and gender-matched normal controls were enrolled in this study.The genomic DNA was extracted from the peripheral blood samples of the subjects,and analysis of the VEGF polymorphisms at the +936 position in the promoter and 3＇-untranslated regions was performed by the restriction fragment length polymorphism method.Frequencies of the VEGF+936C/T genotype were compared between the two groups,and the risk of the VEGF+936C/T gene polymorphism in pre-disposing AMD was evaluated.Results No significant differences were seen in the incidence rates of smoking(P ＝ 0.76),hypertension(P ＝ 0.84),hyperlipidemia (P=0.71),diabetes mellitus (P=0.86) and cardiovascular disease(P=0.89) between the AMD group and the normal control group,and BMI was matched between the two groups (P =0.18).The prevalence of the TT genotype was 9.0％ (18/200)in the AMD group,but that in the normal control was 3.5％ (7/200),showing a significant difference between the two groups (P =0.03).The odds ratio (OR) was 2.73 with a 95％ confidence interval(CI) of 1.11 to 6.68 for AMD in this genotype.The CC and CT genotypes were not significantly different between the two groups (P =0.52,P =0.57).The genotype frequency and allele frequency conformed to HardyWeinberg equilibrium law.There were no significant differences found in the CC,CT,TT genotype frequencies among the early AMD,geographic atrophy AMD and choroidal neovascular AMD (all at P＞0.05).Conclusions The VEGF+936TT genotype is associated with AMD in Han Chinese population. Key words: Age-related macular degeneration; Vascular endothelial growth factor; Gene polymorphism; Han Chinese