GCK and type 2 diabetes mellitus: Genetic variants related to MODY are found in 5.1% of patients who were pre-diagnosed with type 2 diabetes, 0.45% of patients pre-diagnosed with antibody-positive type 1 diabetes, and 4.4% of patients pre-diagnosed with antibody-negative type 1 diabetes.[14] Fourteen different genetic mutations related to MODY have been identified, including mutations in genes encoding hepatocyte nuclear factor-4 alfa (HNF-4α; MODY 1), glucokinase (GCK; MODY 2), HNF-1α (MODY 3), and HNF-1β (MODY 5).