We aimed to investigate the associations of polymorphisms in Canonical Wnt/β-catenin pathway (WNT) signaling genes (including low-density lipoprotein-related protein 5 [LRP5] and transcription factor 7-like 2 [TCF7L2] gene) and the downstream gene glucagon (GCG) and risk of type 2 diabetes mellitus (T2DM) in a Han Chinese population. This evidence concerns the gene GCG and diabetes mellitus.