GCG and disorder of glycogen metabolism: These three patients presented with unusual findings: variable fasting tolerance, intermittent ketonemia and absence of postprandial hyperglycemia/hyperlactatemia in GSD type 0; hypoketotic hypoglycemia responsive to glucagon, with increased NEFA in HI; absence of fructose containing foods aversion, fasting hypoketotic hypoglycemia responsive to glucagon, suppressed NEFA, increased liver enzymes and renal tubular dysfunction in HFI (1).