KCNJ11 encodes an inward rectifier potassium channel that forms the pore of ATP-sensitive potassium (KATP) channels, which are critical regulators of glucose-stimulated insulin secretion in pancreatic β-cells 1. The channel partners with ABCC8/SUR1 to form functional KATP channels that sense intracellular ATP/ADP ratios and regulate membrane potential accordingly 1. In pancreatic β-cells, these channels normally close when glucose levels rise, leading to membrane depolarization and insulin release. Mutations in KCNJ11 cause severe metabolic disorders through disrupted insulin regulation 2. Inactivating mutations lead to congenital hyperinsulinism (CHI), causing excessive insulin secretion and severe hypoglycemia, particularly in neonates 34. Conversely, activating mutations result in neonatal diabetes by preventing proper insulin secretion 1. KCNJ11 mutations account for approximately 36-45% of CHI cases, with recessive mutations often causing diazoxide-unresponsive disease requiring surgical intervention 23. The E23K polymorphism (rs5219) has been associated with increased type 2 diabetes risk in some populations, including Chinese Han and Arab populations 56. Early genetic diagnosis is crucial for appropriate clinical management, as focal forms may be cured with partial pancreatectomy while diffuse forms require medical management 4.