Polymorphisms of these genes (Ala45Thr [NEUROD1], Ser199Phe [NEUROG3], and Ala98Val [TCF1]) have been postulated to influence the development of type 2 diabetes.
Significant associations between the heterozygote A98V genotype and clinical parameters of insulin metabolism were reported but no relationship with type 2 diabetes was obtained.
The common variants p.I27L (rs1169288), p.A98V (rs1800574) and p.S487N (rs2464196) of the hepatocyte nuclear factor 1-α (HNF1A) gene have been inconsistently associated with impaired glucose tolerance and/or an increased risk of type 2 diabetes mellitus (T2DM).
We hypothesized that common variants at the <i>HNF1A</i> locus (rs1169288 [I27L], rs1800574 [A98V]), which are associated with type 2 diabetes susceptibility, may modify age at diabetes diagnosis in individuals with HNF1A-MODY.
We studied the effect of four common polymorphisms (rs1920792, I27L, A98V and S487N) in and upstream of the HNF-1alpha gene on transcriptional activity in vitro, and their possible association with type 2 diabetes and insulin secretion in vivo.