Correlation between the interactions of ABCA4 polymorphisms and smoking with the susceptibility to age-related macular degeneration

Objective: Our study was aimed to analyze the relationship between retina-specific ATP-binding cassette, sub-family A, member 4 (ABCA4) gene polymorphisms and gene-environment interactions with age-related macular degeneration (AMD) susceptibility. Methods: 98 AMD patients and 110 healthy controls, matched in age and sex, were enrolled in this study. ABCA4 polymorphisms (2633C>A, 5646G>A and 6389T>A) were determined by direct sequencing. Differences of genotype and allele distributions were analyzed by χ² test. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were adopted to represent the relative risk of AMD. Gene-environment interactions were analyzed using crossover analysis. Results: 2633C>A polymorphism had no obvious correlation with AMD risk. Genotype AA and allele A in 5646G>A polymorphism significantly increased the risk of AMD (OR=4.753, 95% CI=1.249-18.085; OR=1.944, 95% CI=1.209-3.126). 6389T>A polymorphism AA genotype had no significant correlation with AMD risk, but the A allele distinctly enhanced the AMD risk (OR=1.681, 95% CI=1.071-2.639). Afterwards, we analyzed the interactions between ABCA4 polymorphisms and smoking on AMD. Smoking had interactions with all of 2633C>A (CC+CA), 5646G>A and 6389T>A polymorphisms, and the interactions were significantly correlated with AMD. Conclusions: 2633C>A (CC+CA) genotype, 5646G>A and 6389T>A polymorphisms of ABCA4 gene and smoking are susceptible factors for AMD, and the interactions of ABCA4 polymorphisms with smoking increased the risk of AMD.