BglII POLYMORPHISM IN ITGA2 GENE IN PATIENTS WITHDIABETIC RETINOPATHY IN THE KAZAKHSTAN POPULATION

Abstract

Introduction. Currently, one in ten adult around the world suffers from diabetes. Diabetic retinopathy is the most
common microvascular complications of type 2 diabetes and a leading cause of blindness in middle-aged people in many
countries. Accelerated thrombus formation observed in diabetic patients is considered one of the main causes of vascular complications, including retinopathy. According to the literature, polymorphism in the α-subunit of the integrin receptor α2β1,
which plays an important role in the initial stages of blood coagulation, may be a risk factor for the development of diabetic
retinopathy.
Purpose: to examine the hypothesis that the BglII polymorphism in ITGA2 gene associated with a predisposition to
retinopathy among patients with type 2 diabetes mellitus in the Kazakhstan population.
Materials and methodology. We compared allele and genotype frequencies between 94 diabetic retinopathy patients,
94 diabetic patients without retinopathy, and 51 healthy controls. Genotypes were determined by PCR-RFLP method.
Results. The genotype distribution in each studied group was compatible with Hardy-Weinberg expectations. The
genotype and allele frequencies were not significantly different between diabetic patients with and without retinopathy.
Instead, both groups of diabetic patients significantly differed in allele (P = 0.021 and 0.002, respectively) and genotype
frequencies (P = 0.042 and 0.005, respectively) from healthy controls. The BglII- allele was significantly associated with
diabetes, OR = 1.81 [95% CI: 1.09–2.99] for the diabetic retinopathy group, and OR = 2.24 [95% CI: 1.34–3.75] for the nonretinopathy diabetic group. The association was also observed in comparisons within the subset of Kazakhs.
Conclusions. In this paper, we have shown that BglII polymorphism in ITGA2 gene may be associated not only with
diabetic retinopathy, but also with type 2 diabetes mellitus. According to our data, the risk allele for diabetes is the wild BglIIallele, and not the minor BglII+, which is considered as such for diabetic retinopathy.