McArdle disease

Myophosphorylase deficiency; Muscle glycogen phosphorylase deficiency; PYGM deficiency

Type V glycogen storage disease (GSD V) is a rare inherited condition in which the body is not able to break down glycogen. Glycogen is an important source of energy that is stored in all tissues, especially in the muscles and liver.

GSD V is also called McArdle disease.

Causes

Symptoms

Exams and Tests

Treatment

Support Groups

Outlook (Prognosis)

Possible Complications

When to Contact a Medical Professional