association between genetic polymorphism of catalase (cat) c-262t, cu/zn superoxide dismutase (sod1) a251g and risk of age-related macular degeneration

background: cells have complex network of antioxidant enzymes that protect cells from induced damages by reactive oxygen species (ros). catalase and superoxide dismutase are known for their role as primary protection against oxidative stress. oxidative damage is an important risk factor in age-related macular degeneration disease (amd). for the first time in this study the impact of genetic polymorphisms of sod1 and cat with amd has been examined. hence, the association between genetic polymorphisms of catalase (cat) c-262t, cu/zn superoxide dismutase (sod1) a251g and risk of exudative amd has been investigated. methods: this study was carried out on blood samples collected from 112 exudative amd patients and 112 healthy individuals. genotyping of cat c-262t and sod1a251g was done by polymerase chain reaction and restriction fragment length polymorphism (pcr-rflp) method. differences in the frequencies were estimated using the χ2 test and risk was estimated with a logistic regression after adjusting for smoking, working place and age status. results: there was significant difference between cat ct+tt genotype and amd disease (p=0.009, or=0.38, 95%ci=0.18-0.78). also t-allele has a significant association with risk of amd and decreases risk of disease (p=0.036, or=0.59, 95%ci=0.36-0.96), but there was no significant differences between sod1a251g and variant homozygous and heterozygous frequencies in patients compared to controls (p=0.589, or=0.77, 95%ci=0.3-1.96). conclusions: the data presented suggest that the t-allele in cat genotypes can increase catalase expression and activity, as a result of which generation of reactive oxygen species (ros) can be decreased. therefore it is suggested that increased expression of cat as a result of t-allele in cat genotypes and existence of t-allele in cat genotypes is associated with decreased risk of amd.