Abstract
Purpose: :
Oxidative stress has been implicated in the pathogenesis of several neurodegenerative diseases, including glaucoma. Superoxide dismutases are important antioxidative enzymes and polymorphisms of their encoding genes have been associated with various age-related diseases. This study reports on the V16A polymorphism of the mitocondrial manganese superoxide dismutase (SOD2) in Estonian patients with primary open-angle glaucoma (POAG).
Methods: :
TaqMan® SNP genotyping assay for the V16A polymorphism (rs4880) in SOD2 was used to genotype POAG patients (N=239) and controls (n=185). Statistical analyses for single factor associations used Χ2-test and binary logistic regression was performed including relevant covariates (age, sex, smoking habits and genotypes).
Results: :
Genotype frequencies for the V16A polymorphism of SOD2 were 20.4 (TT), 52.2 (TC) and 27.4 (CC) % for the control group and 23.4 (TT), 48.5 (TC) and 28.0 (CC) % for the POAG patients. No significant associations were seen between the POAG and the control groups using univariate or multivariate analyses. Among the covariates, current smoking was associated with POAG diagnosis (OR 2.4, 95% CI 1.3-4.6, P=0.008). Also, in the POAG group, TT homozygosity was inversely associated with lower intraocular pressure (IOP) at diagnosis (<27 mmHg, P=0.028) and, also inversely, with early stage glaucoma (stage 1 of 3, P=0.005).
Conclusions: :
Homozygosity for the T allele of the SOD2 V16A polymorphism is associated with higher IOP and mature/terminal stages of glaucoma, indicating a role for oxidative stress in the pathogenesis of POAG.
Keywords: genetics • oxidation/oxidative or free radical damage • visual impairment: neuro-ophthalmological disease