Transcription factor 7-like 2 (TCF7L2) gene polymorphism and complication/comorbidity profile in type 2 diabetes patients

Abstract

Transcription factor 7-like 2 gene (TCF7L2) has been associated with type 2 diabetes. We investigated the association of the rs7903146 SNP in this gene with clinical profile of type 2 diabetes (T2DM) patients. The study involved 980 patients with diabetic nephropathy (44%), diabetic retinopathy (42%), CVD (65%) and early onset of diabetes (45%) and 924 healthy controls. Subjects were genotyped for rs7903146 by PCR-RFLP. Genotype frequencies significantly differed between T2DM patients and controls (p<0.01, odds ratio (OR) for TT genotype 2.49 (95% confidence interval (CI) 1.84-3.39). An association was observed between rs7903146 and nephropathy (p<0.001), with 22% of TT homozygotes in this subgroup vs. 11% in patients without nephropathy (p=0.006, OR for TT 2.83, 95% CI 1.94-4.13). Association was stronger in patients with early onset of diabetes (34% of TT vs. 12% in the late onset, p<0.001). In DN group 71% of TT homozygotes had an early onset (OR 7.64, 95% CI 4.98-11.73 vs. controls). Our results confirm association of rs7903146 in the TCF7L2 gene with increased risk of type 2 diabetes. The T allele is strongly associated with nephropathy, especially in early onset of diabetes.