Assessment of TCF7L2 Gene rs7903146 Polymorphism as Type 2 Diabetes Genetic Risk  Factor within Southern Iraqi Population

Abstract

Objective: To investigate the association between the TCF7L2 rs7903146 polymorphism and type 2 diabetes mellitus susceptibility in a southern Iraqi population Study Design: Case-control studyPlace and Duration of Study: This study was conducted at the Al-Fayhaa Teaching Hospital, Basrah, Iraq, from 1st November 2025 to 31st March 2026. Methods: A total of 184 participants, including 103 patients with T2DM and 81 healthy controls were enrolled. Demographic and clinical data were collected, and genotyping of rs7903146 was performed using the tetra-primer amplification refractory mutation system polymerase chain reaction (Tetra-ARMS PCR). Selected samples were further validated by deoxyribonucleic acid (DNA) sequencing and basic local alignment search tool (BLAST) analysis. Results: The frequency of C allele was significantly higher in controls (90.1%) than in patients (55.3%), suggesting a protective effect. In contrast, the T allele was more prevalent among patients (44.7%) than controls (9.9%), indicating its role as a risk allele. Significant associations were observed between the T allele and increased susceptibility to type 2 diabetes mellitus, with both heterozygous (CT) and homozygous (TT) genotypes showing elevated risk (p<0.01 and p<0.002, respectively). Conclusion: A strong association between the TCF7L2 rs7903146 polymorphism and type 2 diabetes mellitus susceptibility in the studied population.