For Δ2‐h PG, GCK‐MODY patients also had a lower Δ2‐h PG compared to both HNF1A‐MODY (SMD −1.49 [95% CI −1.98, −1.01] mmol/l, p < .001, n = 3; I2 = 0%, Ph = .37) and type 2 diabetes (SMD −1.02 [95% CI −1.32, −0.71] mmol/l, p < .001, n = 1) as well. Here, HNF1A is linked to type 2 diabetes mellitus.