Background: type 2 diabetes mellitus (T2DM) is a metabolic condition associated with increased risk of multiple organ complications. Genetic variations such as rs7903146 (TCF7L2), rs5219 (KCNJ11), rs10946398 (CDKAL1), and rs9939609 (FTO) are shown to be linked to T2DM in many ethnic groups. The objective of this study was to investigate the possible associations of these single nucleotide polymorphisms (SNPs) with the susceptibility of T2DM among Emirati population. 
Methods: the study included 264 unrelated diabetic patients and 153 unrelated healthy controls from Emirati population. DNA was extracted from participants’ saliva samples and genotyped for four SNPs rs7903146 (TCF7L2), rs5219 (KCNJ11), rs10946398 (CDKAL1), and rs9939609 (FTO) using TaqMan® real-Time PCR assays. The associations between the SNPs and T2DM were tested usig a multiple logistic regression model incorporating age, gender, body mass index (BMI), and hypertension as covariates. 
Results: a significant association was observed between the genotype distribution of the SNP rs7903146 (TCF7L2) and T2DM (p=0.0063, OR=1.80). Further analyses indicated that SNP rs7903146 was possibly interacting with age and BMI to influence the susceptibility to T2DM. In addition, rs5219 (KCNJ11) showed significant link with two anthropometric parameters; BMI (p=0.033) and diastolic blood pressure (p=0.041), rs10946398 (CDKAL1) affected glycosylated hemoglobin (p=0.025) and fasting blood glucose (p=0.036), and rs9939609 (FTO) affected BMI (p=0.014), systolic blood pressure (p=0.044), and fasting blood glucose (p=0.034). 
Conclusions: theses findings demonstrate that rs7903146 (TCF7L2) is a risk for T2DM susceptibility among the United Arab Emirates population, while rs5219 (KCNJ11), rs10946398 (CDKAL1) and rs9939609 (FTO) variants are not directly related to T2DM incidence but to some of its risk factors and related traits.

The association of TCF7L2, KCNJ11, CDKAL1 gene, and FTO genes with T2DM in Emirati population