Background:  Type 2 Diabetes Mellitus (T2DM) is a metabolic disorder with a multifactorial etiology, in particular genes and the environment. The Gulf Corporation Council (GCC) countries, including the United Arab Emirates (UAE), have been afflicted by dramatic T2DM rates ranking them among the top 15 countries for diabetes prevalence worldwide. The single nucleotide polymorphisms (SNPs) of the TCF7L2 gene, including rs4506565 and rs12255372, have been well studied in the global population that shows an increase in T2DM risk for the “TT” genotype. However, limited data exists that investigates this association with T2DM in the UAE. Therefore, the aim of this study was to analyze the potential association of these genetic variants and T2DM in the Emirati population. 
Methods: For this control-case study, we genotyped, using Taqman® Real-Time PCR assays, T2DM patients (n=890) and healthy subjects (n=686). The DNA was extracted from saliva and data analysis was done using the following software: R (version 3.3.1) and Stata® (version 13). Results obtained were adjusted by Age, Gender and BMI and stratified by Gender as well.
Results: For all participants, the distribution of rs12255372 alleles showed significant difference between T2DM and control subjects (OR=1.16, 95% CI= [1.00-1.34]; punadjusted=0.042). Concerning rs4506565, no association was found (OR=1.12, 95% CI= [0.97-1.29]; punadjusted=0.120) but after adjusting with Age, BMI and Gender, a significant association was highlighted (padjusted=0.049).  For the gender sub-group analysis, a significant association was found for males for both SNPs without and with adjustment (punadjusted=0.009; padjusted=0.031, p(un)adjusted=0.021 , for rs4506565 and rs12255372 respectively). No association was found for female between T2DM and both SNPs.
Conclusions: These findings suggest that genetic variants of TCF7L2 gene rs4506565 and rs12255372 are associated with increased risk for T2DM in Emirati population, this risk being particularly for the male population.

Investigating the association between T2DM and TCF7L2 gene polymorphisms in the Emirati population