Genetic Susceptibility to Type 2 Diabetes Mellitus Linked to TCF7L2 Rs7903146 Variant in a Northern Nigerian Population

Polymorphisms in the gene encoding transcription factor 7-like 2 (TCF7L2) have been identified as potent genetic risk factors for the development of type 2 diabetes mellitus (T2DM) and its associated complications. This study aimed to investigate the association between the rs7903146 (C/T) polymorphism in the TCF7L2 gene and the risk of developing T2DM in the Murtala Muhammad Specialist Hospital population. A total of forty-three (43) T2DM patients and forty-two (42) healthy controls were recruited for comprehensive assessments of anthropometric, clinical, and genetic parameters. Polymerase Chain Reaction (PCR) was employed to detect the presence of the TCF7L2 rs7903146 C/T polymorphism using allele specific primers, and the resulting PCR products were visualized using 1.5% gel electrophoresis. Significant differences in anthropometric and clinical parameters were observed, including age (p = 0.017), BMI (p = 0.001), and fasting glucose level (p = 0.0001) between the patient and control groups. Analysis of the distribution of the TCF7L2 rs7903146 genotypes and alleles revealed that the TT genotype was more prevalent in the T2DM group (12.19%) compared to healthy controls (2.50%) but showed no significant differences. Similarly, the allelic frequencies of the rs7903146 differ significantly (p = 0.011) between T2DM patients and healthy controls. The frequency of the T allele was more frequent in diabetic patients (36.59%) than in healthy controls (18.75%) and this allele was significantly associated with the risk of Type 2 diabetes (OR of 2.50, 95% CI = 1.22-5.133). These results were adjusted using the genetic model. However, the association was consistent with a dominant model of inheritance (OR=2.9, 95% CI 1.18-7.16, p= 0.019). No significant (p<0.05) association was observed between TCF7L2 genotypes and covariates such as age, gender, BMI, and fasting plasma glucose levels. These findings suggest that the TCF7L2 rs7903146 (C/T) polymorphism is an important genetic risk factor for Type 2 diabetes, pointing to its role in increasing susceptibility to the disease across different populations. However, due to the relatively small sample size and single-center nature of the study, these results may not apply to all groups. Larger, more diverse studies are needed to confirm and expand on these findings.