Association of rs3814570 and rs7094463 polymorphisms in TCF7L2 gene with susceptibility to type 2 diabetes mellitus in a Chinese Uygur population

Genetic polymorphisms of transcription factor 7-like 2 (TCF7L2) on chromosome 10q were reported to be associated with type 2 diabetes mellitus (T2DM) in different populations. The aim of the present study was to investigate the association between the rs3814570 and rs7094463 polymorphisms of the TCF7L2 gene and T2DM in a Chinese Uygur population. A total of 1858 people including 941 T2DM patients and 917 controls were selected for the present study. All T2DM patients and controls were genotyped for the same two single nucleotide polymorphisms (SNPs) (rs3814570, and rs7094463) by using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The rs3814570 polymorphism was found to be associated with T2DM in genotypes, dominant model, recessive model, additive model, and allele frequency (all P<0.05), after adjustment of the major confounding factors, the significant difference was retained (all P<0.05). General linear model analysis showed rs3814570 polymorphism was associated with glucose levels by analyses of a dominant model (P = 0.031). However, the difference did not remain statistically significant after multivariate adjustment (P = 0.059). The CC genotype of rs3814570 had significantly higher plasma glucose levels (7.30 +/- 3.39 mmol/L vs 6.65 +/- 3.17 mmol/L) when compared with the CT + TT genotype. In addition, the frequency of the C-G haplotype was significantly higher in the T2DM patients than in the controls (P = 0.0123), and the frequency of the T-G haplotype was significantly lower in the T2DM patients than in the control subjects (P = 0.0003). The distribution of rs7094463 genotypes, dominant model, recessive model, additive model and allele frequency showed no significant difference between the T2DM patients and control subjects (P>0.05, respectively). Our results indicated that the rs3814570 polymorphism of the TCF7L2 gene was associated with T2DM in the Uygur populations of China. The TT genotype of 3814570 in the TCF7L2 gene might be protective genetic markers of T2DM, the CC genotype of 3814570 might be genetic risk markers of T2DM in the Uygur population in China.