Glycogen phosphorylase V, McArdle's Disease). More than 65 mutations in the PYGM gene that lead to McArdle disease have been identified to date. Symptoms of McArdle disease include muscle weakness, myalgia, and lack of endurance, all stemming from low glucose levels in muscle tissue. Mutations in the liver isoform of glycogen phosphorylase (PYGL) are associated with Hers' Disease (glycogen storage disease type VI). Hers' disease is often associated with mild symptoms normally limited to hypoglycemia, and is sometimes difficult to diagnose due to residual enzyme activity. The brain isoform of glycogen phosphorylase (PYGB) has been proposed as a biomarker for gastric cancer.
Glycogen storage disease type III 4-alpha-glucanotransferase gene and mutations to it, are at the root of this condition. The gene is responsible for creating glycogen debranching enzyme, which in turn helps in glycogen decomposition. In terms of the diagnosis for glycogen storage disease type III, the following tests/exams are carried out to determine if the individual has the condition: The differential diagnosis of glycogen storage disease type III includes GSD I, GSD IX and GSD VI. This however does not mean other glycogen storage diseases should not be distinguished as well. Clinical manifestations of glycogen storage disease type III are divided into four classes: Treatment