Glutathione S-transferase M1 and T1 gene polymorphisms in psoriasis patients: a pilot case-control study

Background The exact etiology of psoriasis remains unknown; nevertheless, it has been found that oxidative stress plays a vital role. Among the multiple antioxidant enzymes, genetic polymorphisms in the Glutathione S-Transferases (GSTs) led to an imbalance in the antioxidant system, resulting in increased levels of reactive oxygen species. Accordingly, the polymorphism in these genes could increase the susceptibility to psoriasis. Objectives To assess the association between Glutathione S-Transferase M1 (GSTM1) and Glutathione S Transferase Theta-1 (GSTT1) gene polymorphisms in psoriasis patients compared to healthy controls. Methods A total of 200 participants, 100 psoriasis cases who were assessed by the Psoriasis Area and Severity Index (PASI), and 100 healthy controls were included. DNA extraction was done followed by multiplex PCR to detect genetic polymorphism in the GSTM1 and GSTT1 genes, Finally, the relation between the presence of polymorphism and the severity of psoriasis was estimated. Results The null genotype frequency of GSTM1 and GSTT1 was 76.0% and 58.0%, respectively among psoriasis patients, while it was 58.0% and 55.0%, respectively among healthy controls. There was a significantly higher risk for psoriasis in patients with the null genotype GSTM1 (OR=2.293) as compared to controls. On the other hand, there was no statistically significant relation between their polymorphisms and family history, psoriasis severity, and PASI score. Conclusion The null genotype GSTM1 could increase the risk of psoriasis susceptibility especially among males.