Gene-gene interactions and the contribution of polymorphic loci of the KCNJ11, ADIPOQ, omentin, leptin, TCF7L2 and PPARg genes to the development of type 2 diabetes mellitus in the Kyrgyz population: a case-control genetic association study using MDR analysis

There are many genetic loci associated with type 2 diabetes mellitus (T2DM). The genetic factors involved in the development of the T2DM can depend on the nature of genetic variation within and across different ethnic groups. Aims — the aim of this study was to investigate the gene-gene interactions and to determine the role of the KCNJ11 (Glu23Lys), ADIPOQ (G276T), omentin (Val109Asp), leptin (G2548A), TCF7L2 (IVS3C/T), PPARg (Pro12Ala) genes in the development of type 2 diabetes mellitus (T2DM) in the Kyrgyz population using MDR analysis. Material and methods. We examined 114 patients (53 females and 61 males; mean age, 54±7.4) with T2DM and 109 apparently healthy controls (48 females and 61 males; mean age, 50±8.4). Polymorphisms of the KCNJ11 (Glu23Lys), ADIPOQ (G276T), omentin (Val109Asp), leptin (G2548A), TCF7L2 (IVS3C/T), PPARg (Pro12Ala) genes were defined by PCR-RFLP assay. Results. Among the six genes (KCNJ11, ADIPOQ, omentin, leptin, TCF7L2, PPARg) included in this study, the most significant contribution to the development of T2DM in the Kyrgyz population was detected for the ADIPOQ (2.17%) and KCNJ11 genes (2.01%). The heterozygous genotype G276T (OR=1.79 CI 95% 1.05—3.05; p=0.036) and the 276T allele (OR=1.68 CI 95% 1.09—2.60; p=0.025) of the ADIPOQ gene were associated with a high risk of developing T2DM in the Kyrgyz population. The 23Lys allele of the KCNJ11 gene was significantly associated with T2DM in the Kyrgyz population (OR=1.62 CI 95% 1.10—2.38; p=0.019). The allele and genotype frequencies of the omentin (Val109Asp), leptin (G2548A), TCF7L2 (IVS3C/T), PPARg (Pro12Ala) genes did not differ between the studied groups (p>0.05). Conclusions. In Kyrgyz population, the polymorphic loci Glu23Lys of the KCNJ11 gene, the 276T allele and genotype G276T of ADIPOQ are associated with T2DM. The omentin (Val109Asp), leptin (G2548A), TCF7L2 (IVS3C/T), and PPARg (Pro12Ala) genes alone do not have such a significant impact on the development of type 2 diabetes; they contribute to the phenotypic development of T2DM mainly due to gene-gene interactions.