Superoxide Dismutase Gene Polymorphisms in Patients with Age-related Cataract

ABSTRACT

Background: Functional polymorphisms in genes encoding antioxidant enzymes may result in reduced enzyme activity and increased levels of reactive oxygen species, such as superoxide radicals, which in turn may contribute to increased risk of age-related disorders. Copper–zinc superoxide dismutases, SOD-1 and SOD-3, and manganese superoxide dismutase, SOD-2, are enzymes involved in the protection against oxidative stress and detoxification of superoxide. In this study, we investigated a number of disease-associated single nucleotide polymorphisms (SNPs) of SOD1, SOD2 and SOD3, in patients with age-related cataract.

Materials and methods: The study included an Estonian sample of 492 patients with age-related cataract, subgrouped into nuclear, cortical, posterior subcapsular and mixed cataract, and 185 controls. Twelve SNPs in SOD1, SOD2 and SOD3 were genotyped using TaqMan Allelic Discrimination. Haplotype analysis was performed on the SNPs in SOD2.

Results: None of the studied SNPs showed an association with risk of cataract. These results were consistent after adding known risk factors (age, sex and smoking) as covariates in the multivariate analyses and after stratification by cataract subtype. Analysis of SOD2 haplotypes did not show any associations with risk of cataract.

Conclusions: If genetic variation in genes encoding SOD-1, SOD-2 and SOD-3 contributes to cataract formation, there is no major contribution of the SNPs analyzed in the present study.

• Cataract
• oxidative stress
• single nucleotide polymorphisms
• SOD genes

ACKNOWLEDGMENTS

The authors are grateful for the technical assistance and advice of Mrs Mona Seibt Palmér.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

This work was supported by grants from the Swedish Research Council (#2011-3132), Swedish government (“Agreement concerning research and education of doctors”; ALF17 GBG-145921), Göteborg Medical Society, Marianne and Marcus Wallenberg Foundation, Stiftelsen Handlanden Hjalmar Svenssons forskningsfond, Stiftelsen Handlanden Herman Svenssons fond för blinda och synsvaga, Ögonfonden and Kronprinsessan Margaretas Arbetsnämnd för Synskadade.