Genetic polymorphisms of catalase (rs7943316), glutathione peroxidase-1 (rs1050450), and transferrin (rs8177178) in keratoconus on a limited group of Russian patients

A pilot study of the association of single nucleotide polymorphisms in catalase (rs7943316), glutathione peroxidase-1 (rs1050450), and transferrin (rs8177178) genes with the risk of keratoconus development was conducted in a sample of Russian patients. Genotyping was performed by analyzing the polymorphism of the lengths of restriction fragments using a polymerase chain reaction. Venous blood samples from 25 patients with keratoconus treated at the Ophthalmology Clinic of the Kirov Military medical Academy in 2019 and 2020 were examined. The control group included 20 patients who had no clinical signs of keratoconus. The effect of the single nucleotide polymorphism rs7943316 of the catalase gene on the risk of keratoconus development has not been established. The T allele of the glutathione peroxidase-1 gene containing the rs1050450 polymorphism slightly increases the risk of keratoconus compared with the C allele (odds ratio = 1.91; 95% confidence interval = 0.75–4.85; p = 0.17). A moderate association of the A allele of the transferrin gene containing rs8177178 polymorphism with the occurrence of keratoconus and an increase in the incidence of the disease associated with the AG genotype was revealed (odds ratio = 5.67; 95% confidence interval = 1.07–30; p = 0.12). Thus, when examining a limited sample of Russian patients with keratoconus, it was not possible to identify a link between the disease and single nucleotide polymorphisms of catalase rs7943316 and glutathione peroxidase-1 rs1050450. The relationship between the polymorphism of the transferrin rs8177178 gene (allele A and genotype AG) and the risk of keratoconus development was weak and not significant. Thus, expanding the study sample and further studying the polymorphisms of the transferrin gene that affect the structure of the enzyme and reduce the effectiveness of antioxidant protection of the cornea were recommended.