Association between the 25129A>C polymorphism of the nuclear respiratory factor 2 gene and age-related macular degeneration

Introduction
Oxidative stress belongs to the main factors of pathogenesis of age-related macular degeneration, characterized by the damage to the retinal pigment epithelium cells and photoreceptors. Retinal pigment epithelium cells are rich in mitochondria, producing large amount of reactive oxygen species, which are by-products of the activity of the respiratory chain. The distribution in the activity of the chain may be evoked by the release of cytochrome C from the mitochondrion to the cytoplasm. This process may activated by nuclear respiratory factor 2, Nrf2, which is encoded by a highly polymorphic gene. In this study we examined the association between age-related macular degeneration risk and the 25129A>C polymorphism of the gene encoding nuclear respiratory factor 2 (rs12594956).

Material and methods
Genotypes were determined in DNA from peripheral blood lymphocytes of 281 patients with age-related macular degeneration (181 with wet form of the disease and 101 with its dry form), and 105 controls by PCR-restriction fragment length polymorphism.

Results
A weak association (OR 1.96; p = 0.023) between the C/C genotype of the 25129A>C polymorphism and the occurrence of age-related macular degeneration was found. A stronger association was observed between dry age-related macular degeneration occurrence and the C/C genotype of the polymorphism (OR 2.23; p = 0.018). The A/C genotype decreased the risk of age-related macular degeneration and its dry form (OR 0.51; p = 0.023 and 0.44; p = 0.018, respectively). Potential risk factors such as age, gender, smoking habit, living environment (rural or urban) and family status of age-related macular degeneration increased the risk of AMD associated with the C/C genotype (OR 2.52; p = 0.012).

Conclusions
The 25129A>C polymorphism of the NRF2 gene may be associated with age-related macular degeneration.