Glycogen storage disease type V (GSDV); Myophosphorylase deficiency; Muscle glycogen phosphorylase deficiency; PGYM deficiency
There is no specific treatment, but you can manage the symptoms by improving exercise tolerance and controlling physical activity. Avoid excessive or intense exercise.
Dietary management should include having a supply of glucose (candy, for example) on hand if you need to replace energy.
Avoid general anesthesia.
For additional information and resources, visit the Association for Glycogen Storage Disease at
People with McArdle syndrome can live a normal life by managing their physical activity.
Exercise may produce muscle pain, or even breakdown of skeletal muscle, a condition called rhabdomyolysis. This is associated with burgundy-colored urine and a risk for kidney failure, if severe.
Contact your health care provider if you have repeated episodes of sore or cramped muscle after exercise, especially if accompanied by burgundy or pink urine.
Consider genetic counseling if you have a family history of McArdle disease.