ABSTRACT
The glycogen storage diseases are characterized by the deposition of glycogen in tissue cells. The glycogen from the original patient was isolated by R. Schonheimer and was found not to differ from normal glycogen in optical rotation or in its composition of glucose residues. Glycogen is a branched, polydisperse molecule that has been recognized since the time of Claude Bernard as the storage form for carbohydrates in animal tissues. The phosphorolysis of glycogen catalyzed by phosphorylase splits off glucose units until the 1,6 branch points are approached. Hepatic metabolism of glycogen is critical for glucose homeostasis; hepatic glycogenoses present classically with hypoglycemia. The Fanconi-Bickel syndrome combines a hepatic glycogen storage disease with a Fanconi syndrome pattern of renal tubular dysfunction. Muscle glycogen is used to make adenosinetriphosphate for contraction; glycogenoses of muscle present with cramps, weakness, stiffness, or rhabdomyolysis.
