When GCK-DM, MDM, T1DM, and T2DM patients were pooled into one non-HNF1A-DM group, it was observed that the LDL-c levels were significantly lower in HNF1A-DM patients (1.90 ± 0.77 mmol/l) than in non-HNF1A-DM patients [(2.44 ± 0.78 mmol/l), P = 0.045]. Here, GCK is linked to diabetes mellitus.