Association of TCF7L2 gene variant with T2DM, T1DM and gestational diabetes in the population of Northeastern UP, India

The non-coding variant (rs7903146) for transcription factor 7-like 2 gene (TCF7L2) is known to be associated with increased risk of type 2 diabetes mellitus (T2DM), but this variant is also associated with type 1 diabetes mellitus (T1DM) and gestational diabetes mellitus (GDM). The association of TCF7L2 variant rs7903146 was confirmed in the Indian and European population for T2DM. We investigated whether TCF7L2 variant rs7903146 is associated with T1DM, T2DM and GDM in Uttar Pradesh population. Three hundred thirty-three patients were genotyped having T2DM, 175 patients with T1DM and 102 gestational GDM and 487 healthy controls. The rs7903146 polymorphism was genotyped using the PCR-based RFLP method. The heterozygous CT genotype of rs7903146 had a 0.0437-fold increased risk in T2DM [OR (95 % CI) 0.0437 (0.0059-0.3213), p < 0.00001] and a 0.0081-fold increased risk in T1DM [OR (95 % CI) 0.0131 (0.0011-0.0589), p < 0.00001] in comparison to control. The frequency of CT genotype was significantly higher in T2DM than in controls (10.51 vs. 0.62 %) with an OR of 0.0528 (95 % CI 0.0182-0.0189, p < 0.0001). The frequency of the CT genotype was significantly higher in T1DM than in controls (38.86 vs. 0.62 %) with OR of 0.0098 (95 % CI 0.0051-0.0497, p < 0.0001). The frequency of CT genotype in T1DM was more than in T2DM. No association was observed in GDM. The study proved that the rs7903146 variant of the TCF7L2 gene is associated with T2DM and T1DM but not GDM in the North Indian population of Uttar Pradesh.