Association of KCNJ11 gene rs5219 polymorphism with type 2 Diabetes mellitus

Abstract

Introduction: Genome-wide association studies (GWAS) have shown that some polymorphisms in the KCNJ11 gene contribute to the development of type 2 diabetes. ATP-sensitive potassium (KATP) channels play a key role in insulin secretion from pancreatic beta cells. Beta cell KATP channel is composed of pore subunits Kir6.2 (KCNJ11). KCNJ11 rs5219 polymorphism is caused by a switch of guanine to adenine at codon 23, resulting in a glutamic acid to lysine amino acid substitution and thereby a critical inhibition of glucose-induced insulin secretion. Objective: Determine the association between the KCNJ11 gene rs5219 polymorphism and type 2 diabetes mellitus Materials and Methods: This study was designed as a case-control study. In the case group, 52 individuals with type 2 diabetes mellitus (T2DM) were selected, and in the control group, 52 individuals were considered healthy according to certain criteria. Biochemical analyses were measured using a fully automatic analyzer 'Respons-910' from the German company Diasys. Blood glycated hemoglobin (HbA1c) from EDTA was measured with a semi-automatic SD A1cCare analyzer. DNA was extracted according to the accompanying protocol using “Quick Prep Universal Genome DNA Kit” (Cat.№. A0204) by Hualikexi, China. KCNJ11 gene rs5219 polymorphism was defined using a unique primer to amplify and the target sequence defined by the restriction fragment length polymorphism-PCR method. Amplified DNA were digested using BanII restriction enzyme. The digested products were determined by 3% gel electrophoresis with ethidium bromide. SPSS 23.0 was used to process the collected data. Results: Significant differences were observed for fasting plasma glucose, HbA1c and triglyceride (p<0.05). The frequency of KK genotype and K allele was higher in the case group than the control group (p <0.05). Conclusion: The high frequency of K alleles and KK genotypes of the KCNJ11 gene rs5219 polymorphism in the case group suggests that they may be more susceptible to type 2 diabetic mellitus.