Taken together, the specific mutation in HNF4A caused a group of disorders, including hypoglycemia, renal FS, and liver dysfunction, similar to Fanconi–Bickel syndrome, a rare type of glycogen storage disease caused by solute carrier family 2 member 2 (SLC2A2) defects with which FS is easily confused. The gene discussed is HNF4A; the disease is Glycogen storage disease due to glycogenin deficiency.