Glycogen storage disease type III enzymes to further convert these branched glycogen polymers to glucose, limit dextrinosis abnormally accumulates in the cytoplasm. Glycogen is a molecule the body uses to store carbohydrate energy. Symptoms of GSD-III are caused by a deficiency of the enzyme amylo-1,6 glucosidase, or debrancher enzyme. This causes excess amounts of an abnormal glycogen to be deposited in the liver, muscles and, in some cases, the heart. Glycogen storage disease type III presents during infancy with hypoglycemia and failure to thrive. Clinical examination usually reveals hepatomegaly. Muscular disease, including hypotonia and cardiomyopathy, usually occurs later. The liver pathology typically regresses as the
Glycogen phosphorylase conformation from a tense to a relaxed form. This relaxed form has similar enzymatic properties as the phosphorylated enzyme. An increase in ATP concentration opposes this activation by displacing AMP from the nucleotide binding site, indicating sufficient energy stores. Upon eating a meal, there is a release of insulin, signaling glucose availability in the blood. Insulin indirectly activates PP-1 and phosphodiesterase. The PP-1 directly dephosphorylates glycogen phosphorylase a, reforming the inactive glycogen phosphorylase b. The phosphodiesterase converts cAMP to AMP. This activity removes the second messenger (generated by glucagon and epinephrine) and inhibits PKA. In this manner, PKA can no