However, GCK‐MODY patients had lower 2‐h PG compared to both HNF1A‐MODY (SMD −1.60 [95% CI −2.44, −0.76] mmol/l, p < .001, n = 5; I2 = 82%, Ph <.01) and type 2 diabetes patients (SMD −1.06 [95% CI −1.65, −0.47] mmol/l, p < .001, n = 2; I2 = 90%, Ph <.01). Here, HNF1A is linked to type 2 diabetes mellitus.