Pigment Epithelium-Derived Factor Gene Met72Thr Polymorphism Is Associated With Increased Risk of Wet Age-related Macular Degeneration

Abstract

To investigate the Met72Thr (T/C) polymorphism (rs1136287) of pigment epithelium-derived factor (PEDF) gene exon 3 in unrelated Taiwan Chinese patients with late age-related macular degeneration (AMD) and control subjects without AMD. Retrospective case-control study. We enrolled 190 unrelated Taiwan Chinese patients with late AMD and 90 age- and gender-matched control subjects. Grading of late AMD was classified based on a standardized set of diagnostic criteria established by the International Age-Related Maculopathy Epidemiologic Study. Late AMD was classified as either atrophic (dry, grade 4) or neovascular (wet, grade 5). Atrophic AMD refers to dry late-stage AMD without neovascularization, and wet AMD refers to neovascular AMD. Genomic deoxyribonucleic acid was prepared from peripheral blood obtained from all AMD patients and control subjects. Polymerase chain reaction analysis was used to analyze this polymorphism. Of the 190 participants with late AMD, atrophic AMD was diagnosed in 104 patients and wet AMD was diagnosed in 86 patients. The genotype distribution of the Met72Thr (T/C) variant of PEDF was TT (homozygous T), TC (heterozygous), and CC (homozygous C). The T allele was found significantly more frequently in wet AMD patients than in controls (50% vs 31%; P =.0005). The allele frequencies in atrophic AMD (30%) and controls (31%) did not differ significantly (all P = .87). The homozygous T genotype was more prevalent in wet AMD than in controls (26/86 [30%] vs nine/90 [10%]; odds ratio, 3.9; all P = .0015). The homozygous T genotype in atrophic AMD patients (8%) and controls (10%) did not differ significantly (all P = .75). Our data suggest that the PEDF Met72Thr T allele may be a risk factor for wet AMD in the Taiwan Chinese population. PEDF may play a role in the pathogenesis of wet AMD.