Transcription factor 7-like 2 (TCF7L2) rs12255372 variant and the risk of type 2 diabetes mellitus among the Kurdish population in Erbil, Iraq

Background The genetic predispositions related to type 2 diabetes (T2D) in the Middle East are poorly understood. One of the most common single-nucleotide polymorphisms (SNP) located in the transcription factor 7-like-2 (TCF7L2) gene is rs12255372 variant which elucidated a significant role in developing T2D, especially in the European population. The current study is the first to have examined the association between TCF7L2 rs12255372 variant and T2D among the Iraqi Kurdish population from Iraq. Methods Three hundred participants were enrolled in this study: 150 were type 2 diabetic patients and 150 were normoglycemic controls. For genotyping rs12255372 (G > T) variant, Tetra ARMS-PCR was used which is high-throughput, cost and time effective technique. Results The genotypic frequencies in the additive genetic model (co-dominant) for GG, GT, and TT were 62.7%, 24%, and 13.3% in the normoglycemic controls, respectively, and for the diabetic patients were 50.7%, 20%, and 29.3%, respectively. The TT genotype was found considerably higher in cases when matched to the normoglycemic controls in both co-dominant and recessive models with OR (95% CI) = 2.64 (1.29-5.41) (p value = 0.006) and OR (95% CI) = 1.531 (1.232-1.902) (p value = 0.001), respectively. These frequencies indicated that the carriers of the TT genotype were more susceptible to T2D compared to other genotypes. The T allele showed a high significant frequency in T2D patients compared to the normoglycemic controls with OR (95% CI) = 1.38 (1.16-1.59) (p value = 0.000). Conclusion Our results suggest rs12255372 T allele as a putative risk factor that increases the susceptibility of T2D among the Iraqi Kurdish population.

Automated summary

This study is the first to investigate the association between TCF7L2 rs12255372 variant and T2D in the Iraqi Kurdish population, revealing that the TT genotype is significantly associated with increased risk of T2D.