Glycogen storage disease type VI Glycogen storage disease type VI Glycogen storage disease type VI (GSD VI) is a type of glycogen storage disease caused by a deficiency in liver glycogen phosphorylase or other components of the associated phosphorylase cascade system. It is also known as "Hers' disease", after Henri G. Hers, who characterized it in 1959. The scope of GSD VI now also includes glycogen storage disease type VIII, IX (caused by phosphorylase b kinase deficiency) and X (deficiency protein kinase A). The incidence of GSD VI is approximately 1 case per 65,000–85,000 births, representing approximately 30% all cases of glycogen storage disease. Patients
Glycogen debranching enzyme glucoamylase, respectively. Their active sites are selective towards the respective substrates, ensuring proper activation of GDE. Besides the active sites GDE have additional binding sites for glycogen, which are important for its recruitment to glycogen. Mapping the disease-causing mutations onto the GDE structure provided insights into glycogen storage disease type III. The official name for the gene is "amylo- α- 1,6- glucosidase, 4- α- glucanotransferase", with the official symbol AGL. AGL is an autosomal gene found on chromosome lp21. The AGL gene provides instructions for making several different versions, known as isoforms, of the glycogen debranching enzyme. These isoforms vary