Glutathione S-transferase GSTM 1, null genotype may be associated with susceptibility to age-related cataract

Abstract

Background: Age-related cataract (ARC) is the leading cause of visual disability and reversible blindness all over the world. The different expressions of GST isozymes among animals may explain the variations in the cataract formation caused by oxidative stress.

Objectives: In this study, we evaluated the distribution of GST gene polymorphisms in ARC patients and the possible associations between the presence of ARC and GST gene polymorphisms.

Material and methods: The epidemiological data was collected by a standard questionnaire and blood samples were obtained from 130 ARC patients and 159 healthy controls. Data about smoking habits of the groups was recorded. Real-time polymerase chain reaction-based methods were used to detect genetic polymorphisms.

Results: The GSTM 1 null genotype was found to carry an increased risk for developing ARC (OR: 1.84, 95% CI: 1.13-2.99). The frequency of the GSTT 1 null genotype was not significantly different among the ARC patients and the controls (OR: 1.0, 95% CI: 0.64-1.6). The GSTP 1 Val/Val genotype was also not significantly different among the ARC patients and control groups (OR: 1.06, 95% CI: 0.50-2.23). GSTM 1 null genotype was highly frequent in non-smokers (OR: 3.25, 95% CI: 1.66-6.35) and moderately frequent in smokers (OR: 2.50, 95% CI: 1.28-4.86). Also, carrying the combined genotypes of GSTM 1 null, GSTT 1 and GSTP 1 105-Val allele was seen to have an increased risk of developing ARC (OR: 2.91, 95% CI: 1.31-6.44).

Conclusions: This data may provide evidence that GSTM 1 gene polymorphisms may be associated with genetic susceptibility to develop ARC. Larger studies are warranted to verify these findings.