Abstract
Purpose: :
Oxidative stress plays a major role in the development of age-related macular degeneration (AMD). In a previous study an association was described between polymorphisms in genes encoding components of the glutathione S-transferase (GST) antioxidant system and the development of AMD. However, the sample size in that study was very small (35 patients and 159 control subjects). This study was conducted to investigate these relations in a larger cohort.
Methods: :
DNA samples of 760 AMD patients and 576 race-matched controls from the EUGENDA database were genotyped for deletion polymorphisms in GSTM1 and GSTT1 that result in no activity of the corresponding enzymes, and a functional polymorphism in GSTP1 (p.Ile105Val) that lowers the enzyme activity. The Chi-square test was used to determine whether the genotype frequencies in patients differ from those in controls.
Results: :
No direct associations were observed between the GSTM1, GSTT1 or GSTP1 genotypes and AMD. Also, combined genotype analyses did not reveal any associations. Results did not change after correction for sex, age and smoking status in logistic regression analysis.
Conclusions: :
Our results are in contrast with the results of a previously reported study, since we could not confirm the observed associations using a large AMD cohort. Our data strongly indicate that the GSTM1, GSTT1 and GSTP1 genotypes do not confer a risk on the development of AMD.
Keywords: age-related macular degeneration • genetics • clinical (human) or epidemiologic studies: risk factor assessment