Tcf7l2 Gene Polymorphism in T2dm with Patients in Turkish Population

Abstract

Diabetes Mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia resulting from defects of insulin secretion and/or increased cellular resistance to insulin. Chronic hyperglycemia and other metabolic disturbances of DM lead to long-term tissue and organ damage as well as dysfunction involving the eyes, kidneys, and nervous and vascular systems. Type 2 Diabetes mellitus; is the most common form of DM worldwide, and its prevalence is increasing. Its underlying defects can vary from predominant insulin resistance with relative insulin deficiency to a predominant insulin secretory defect with insulin resistance. Transcription 7-like 2 (TCF7L2) protein has been implicated in blood glucose homeostasis. The transcription factor 7-like 2 (TCF7L2) gene is a member of the T-cell factor (TCF)/lymphoid enhancing factor family which encodes a high mobility group (HMG) box-containing transcription factor that plays a key role in the Wnt signaling pathway. The key effector of the canonical Wnt signaling pathway (defined as Wnt pathway hereafter) is the bipartite transcription factor β-cat (β-catenin)/TCF, formed by β-cat and a member of the TCF family [TCF-1/TCF7, LEF-1, TCF-3/TCF7L1 and TCF-4/TCF7L2]. In the absence of Wnt signaling, these HMG box TCF proteins function in the nucleus as transcriptional repressors of the Wnt target genes. TCF7L2 gene is located in chromosome 10q25.3, spans 215.9 kb and contains 14 exons (NCBI build 36.2). However, a previous study has shown that TCF7L2 has 17 exons, of which five are alternative splicing. Genetic variants of gene are associated with increased risk of type 2 diabetes. Common polymorphisms of the transcription factor 7-like 2 gene (TCF7L2) have recently been associated with Type 2 Diabetes all population. The prevalence of Type 2 Diabetes shows wide ethnic and geographic variations. In this study, we analyzed three polymorphisms in the TCF7L2 gene, rs12255372, rs11196205 and rs7901695 using a case-control design in 163 individuals (113 unrelated T2DM patients and 50 normoglycemic controls) to assess their association with T2DM risk in the Turkish population.