Analysis of Glutathione S-transferase M1 (GSTM1) Deletion in Diabetic Retinopathy

Abstract Diabetic retinopathy is a common complication of diabetes mellitus that affects retinal blood vessels. Chronic extra cellular hyperglycemia in diabetes stimulates reaction oxygen species (ROS) production، and increase oxidative stress. Glutathion S- transferases (GSTs) enzymes have been shown to protect human from reaction oxygen compounds damage. GSTM1 gene polymorphic in human and deletion in the gene result in virtual absence of enzyme activity. The aim of this study was to evaluate the association of GSTM1 gene deletion with diabetic retinopathy. In this molecular study، 80 patients with diabetic retinopathy and 80 healthy individuals were tested for deletion polymorphism GSTM1. Genomic DNA was extracted from peripheral blood of the patients and controls (having obtained written informed consents from them). Genotypes were determined by polymerase chain reaction (PCR). Statistical analysis was performed using the MedCalc program Of the 80 patients، there were 9 with GSTM1 gene deletion while، deletion genotype GSTM1 was found in none of the healthy subjects. Statistical analysis of the gene GSTM1، OR=21. 39، 95% CI=1. 22-374. 14، P 0. 05 demonstrates a significant association between GSTM1 deletion genotype frequencies in both patient and control groups. A significant association was found between GSTM1 gene deletion and diabetic retinopathy. Larger population-based studies are needed to more clarify the relationship between diabetic retinopathy and GSTM1 polymorphism. Conflict of interest: non declared