Association of KCNJ11 (E23K) Gene Polymorphism with Susceptibility to Type 2 Diabetes in Bangladeshi Population: A Case-control Study

Abstract

Type 2 diabetes mellitus (T2DM) is a complex, multifactorial metabolic disease that involves a number of interactions between genetic and environmental factors. There are gene variants that are involved in insulin secretion control including KCNJ11 which have been found to contribute to the susceptibility of T2DM in different populations. Nonetheless, there is limited information on people of Bangladesh. The purpose of the study was to examine the relationship between the KCNJ11 E23K (rs5219) polymorphism and T2DM among Bangladeshi adults as well as conducting clinical and biochemical characterization. The sample size was 310 consisting of 210 T2DM patients and 100 non-diabetic controls. The clinical and biochemical parameters were analyzed with the help of standard laboratory techniques. Genomic DNA was extracted from peripheral blood samples, and the KCNJ11 E23K polymorphism was analyzed by PCR followed by Sanger sequencing in a subset of 110 participants, including 55 T2DM cases and 55 controls, selected based on DNA quality, sample availability, and resource feasibility. Genotype distributions of cases and controls were compared using the chi-square test. Fasting plasma glucose, 2-hour plasma glucose, systolic blood pressure, serum triglycerides and creatinine levels were significantly higher in T2DM patients than in controls (p < 0.001), while HDL cholesterol levels were significantly lower in T2DM patients than in controls (p < 0.001). There were no significant differences seen in diastolic blood pressure, total cholesterol or LDL cholesterol. Genotype analysis showed that the AA genotype was present in 25 T2DM patients (45.45%) and 21 controls (38.18%) among the sequenced subsets. Despite pronounced metabolic alterations among T2DM patients, no significant association was observed between the KCNJ11 E23K polymorphism and T2DM susceptibility in this Bangladeshi population. Larger studies incorporating multiple genetic variants and broader population coverage are warranted to further elucidate the genetic architecture of T2DM in South Asian populations.