Tumor necrosis factor-alpha gene promoter −308G/A and −238G/A polymorphisms in mexican patients with type 2 diabetes mellitus

Abstract

The association between some Tumor necrosis factoralpha (TNF ) promoter polymorphisms and Type 2 diabetes mellitus (T2DM) remains controversial. Ethnic differences may play a role in these conflicting results. The aim of this study was to investigate the association between −308G/A and −238G/A polymorphisms located in the promoter region of the TNF gene and T2DM in Mexican mestizo patients. Nine hundred four individuals (259 patients with T2DM and 645 controls) were genotyped for the −308G/A and −238G/A polymorphisms by PCR–RFLP.We found that the −238A allele increased the risk of developing T2DM in Mexican patients (OR = 1.57, 95% CI: 1.07–2.29; p = 0.018). Moreover, we found that the frequency of the GA haplotype (created by the −308G and −238A alleles) was significantly increased in patients with T2DMwhen compared with controls (OR = 1.56, 95% CI: 1.05–2.31; p = 0.026). Our results suggest that the −238G/A polymorphism and a specific haplotype (GA) are genetic risk factors for the development of T2DM in Mexican population.