Identification of TCF7L2 Genetic Variants Associated with Type 2 Diabetes in Northern Region of Bangladesh

Abstract

Background: Seemingly harmless nucleotide changes are found in sequence scanning but their possible association with diseases often remains unclear. However, the transcription factor-7-like 2 (TCF7L2) gene has been identified as a major risk associated gene for type 2 diabetes mellitus (T2DM) susceptibility. Identified intronic locus of the gene harbor five diabetes associated polymorphisms including rs7901695. rs7901695 polymorphism has been previously reported to be associated with diabetes type 2 in several ethnic groups but, no genetic analysis has been carried out to show the relationship of rs7901695 with type 2 diabetes in Bangladeshi population. Objective: This study was aimed to investigate the association between T2DM and TCF7L2 variants in Bangladeshi population. Materials and methods: In this research work, 657 individuals from northern region of Bangladesh were analyzed. Out of those, 330 were non-diabetic served as control and 327 were T2DM individuals. For genotyping of TCF7L2 variants, we have used High Resolution Melting (HRM) analysis. Demographic risk factors like body mass index (BMI), triglyceride (Tg), glycalated hemoglobin (HbA1c) and total cholesterol were also investigated routinely. Significance of these risk factors was further analyzed statistically. Results: Allelic frequency of the participants differed significantly (P < 0.05) between T2DM and non-diabetic control. Patients with T2DM had significantly higher values for BMI, Tg, HbA1c and total cholesterol. This study revealed 87 mutations out of 327 T2DM patients while no mutation was detected in healthy person. However, in the allelic distribution of rs7901695, we have found allele type AA in 139 patients and GG in 101. Whereas, polymorphic heterozygous AC in 11 and GC in 23 and homozygous CC in 41 and TT in 12 patients respectively. Conclusion: This study suggests that TCF7L2 genetic variants are closely correlated with T2DM in population of the Northern region of Bangladesh. Keywords: TCF7L2; polymorphism; type 2 diabetes; Bangladeshi population.