GSTs (T1 and M1) population data in patients with glaucoma: genetic screening and ethical aspects

Abstract

Background and Aim: Molecular epidemiology is an interdisciplinary field concerning the analysis of biological indicators and the investigation of individual DNA polymorphisms. The glutathione-S-transferases (GSTs) are one of the most studied metabolic gene families. They are involved in the genesis of oxidative stress and many authors hypothesize that some null polymorphic variants determine increasing toxic effects in tissues. Oxidative stress and antioxidant systems are very important in the onset and progress of glaucoma, one of the leading causes of blindness worldwide. We investigate the association of null variant of GST (M1 and T1) with the risk of primary open angle glaucoma (POAG) and we considered the ethical and legal implications of genetic procedures as a screening tool. Materials and Methods: We conducted a case-control study including 103 unrelated carriers of glaucoma in a southern Italian population (living in Eastern Sicily) and 150 unrelated healthy individuals as controls, whose buccal swabs samples were genotyped for GST polymorphisms using a standardized multiplex PCR based method. Results: In patients with glaucoma (primary open angle glaucoma, POAG) null genotype of the investigated genetic polymorphisms is very common compared to the healthy individuals. The obtained data suggest an influence of the (dual) null genotype on the normal metabolic pathway in the genesis of congenital glaucoma giving to these polymorphisms the role of so-called “indicators of susceptibility”. Conclusions: We conclude that the increased frequency of null GSTs (M1, T1) in patients with glaucoma could be considered a risk factor for incidence of the disease. Screenings can be carried out only in compliance with legislative rules. Keywords: Glaucoma; Glutathione S-transferase; GSTM1; GSTT1