GCK and MODY: Ranging from 80% to 95% of MODY cases, the underlying cause involves the pathogenetic variants of hepatocyte nuclear factor-1 homeobox A (HNF1A), hepatocyte nuclear factor-4 homeobox A (HNF1A), hepatocyte nuclear factor-1 homeobox B (HNF1B), and glucokinase (GCK) genes [4,7].