Glycogen storage disease type IX Glycogen storage disease type IX Glycogen storage disease type IX is a hereditary deficiency of glycogen phosphorylase kinase B that affects the liver and skeletal muscle tissue. It is inherited in an X-linked or autosomal recessive manner. The signs and symptoms in glycogen storage disease type IX include: Most of these signs and symptoms diminish as adulthood sets in. Glycogen storage disease type IX can be inherited via: The diagnosis of glycogen storage disease IX consists of the following: There are two types of this inherited condition, "glycogen storage disease IXa1" and "glycogen storage disease IXa2" that affect the liver
Glycogen phosphorylase is quite stable. The protonated oxygen now represents a good leaving group, and the glycogen chain is separated from the terminal glycogen in an S1 fashion, resulting in the formation of a glucose molecule with a secondary carbocation at the 1 position. Finally, the deprotonated inorganic phosphate acts as a nucleophile and bonds with the carbocation, resulting in the formation of glucose-1-phosphate and a glycogen chain shortened by one glucose molecule. There is also an alternative proposed mechanism involving a positively charged oxygen in a half-chair conformation. The glycogen phosphorylase monomer is a large protein, composed of 842 amino acids