Significant differences in urinary GCR after 24 h of dapagliflozin administration were observed in the studied groups as this rose by 20.51 ± 12.08, 23.19 ± 8.10, and 9.84 ± 6.68 mmol/mmol for HNF1A-MODY (p = 0.0000), GCK-MODY (p = 0.0000), and T2DM (p = 0.0003), respectively. Here, GCK is linked to type 2 diabetes mellitus.