Associations of TLR4 gene polymorphisms with the risk of age-related macular degeneration in a Chinese Han population

Abstract

The study was designed to reveal the relationship of toll-like receptor 4 (TLR4, rs1927914 and rs1927907) polymorphisms with risk of age-related macular degeneration (AMD), as well as the adjustment of this association by some environmental and lifestyle factors in Chinese Han population. TLR4 polymorphisms were genotyped by polymerase chain reaction-restricted fragment length polymorphisms and direct sequencing method in 138 AMD patients and 146 healthy controls. Genotype distribution in the control group was checked with Hardy–Weinberg equilibrium. Association of TLR4 polymorphisms and AMD risk was evaluated by x2 test and adjusted by age and sex, smoking and drinking. Odds ratio (OR) with 95% confidence interval (95% CI) was used to represent the association strength. Logistic regressive analysis was used to calculate the adjusted OR values. CC genotype of rs1927914 had significantly lower frequency in AMD patients (P = .010), indicated a negative association with AMD risk (crude: OR = 0.358, 95% CI = 0.162–0.791; adjusted: OR = 0.355, 95% CI = 0.160–0.789). C allele of rs1927914 might decrease the susceptibility of AMD (crude: OR = 0.698, 95% CI = 0.497–0.982; adjusted: OR = 0.698, 95% CI = 0.495–0.984). No significant association has been discovered between TLR4 rs1927907 polymorphism and AMD susceptibility. Strong linkage disequilibrium existed between rs1927914 and rs1927907 polymorphisms. C-C haplotype was negatively associated with AMD risk (OR = 0.242, 95% CI = 0.121–0.485; OR = 0.242, 95% CI = 0.120–0.488). CC genotype and C allele of rs1927914 were significantly associated with the decreased AMD susceptibility. Abbreviations: AMD = age-related macular degeneration, CI = confidence interval, HSP = Henoch-Schönlein purpura, HWE = Hardy–Weinberg equilibrium, IS = ischemic stroke, OR = odds ratio, PD = Parkinson’s disease, RPE = retinal pigment epithelium, SNP = single nucleotide polymorphism, TLR4 = toll-like receptor 4, TLRs = toll-like receptors, UTR = untranslated region.