Association of IL-4 gene polymorphism and age-related macular degeneration in Taiwanese adults

PurposeThe purpose of this study was to determine whether interleukin (IL)-4 genetic variants are associated with age-related macular degeneration (AMD).MethodsThe genotyping of IL-4 -590 and intron 3 variable number of tandem repeats (VNTR) was conducted for 171 patients with AMD and 134 controls by using TagMan and polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assays.ResultsThere was no difference in distribution of age, sex, body mass index, and status of systemic disease between AMD patients and healthy controls. Significantly, more patients were current smokers in the AMD group compared with the controls (p = 0.038). The genotypes of IL-4 -590 and intron 3 VNTR were associated with the risk of AMD in our results. In the stratification analysis, both IL-4 -590 allelic type and smoking status were independently associated with AMD. No interactions between allelic type and smoking were found to contribute to risk of AMD. The mean AMD score was significantly higher in carriers with IL-4 -590 T/T or T/C genotypes compared with those with C/C.ConclusionsOur results support the hypothesis that polymorphisms of IL-4 -590 and intron 3 VNTR might be a genetic marker for the development of AMD.