Symptoms of McArdle Disease

Now Serving: The Patties 

- the sizzle of the patty juice 

As mentioned in the previous post "Causes of McArdle Disease", it is mentioned that due to a nonsense or missense mutation in the PYGM gene that is coding for myophosphorylase. As a result, muscle cells cannot produce enough energy, so muscles become easily fatigued.

Phosphorylase deficiency causes exercise intolerance, such as cramps, muscle pain and weakness, shortly after beginning exercise.

A person with this disorder may tolerate light-to-moderate exercise such as walking on level ground, but strenuous exercise usually will bring on symptoms quickly. Resting may lead to a “second wind,” in which activity is then better tolerated. Isometric exercises that require strength, such as lifting heavy objects, squatting or standing on tiptoe, also may cause muscle damage.

Symptoms of this disease vary in severity among people and even within the same person from day to day. Symptoms usually don’t persist between attacks, although fixed weakness later in life is possible.

The symptoms are as followed: 

• Burgundy-colored urine (myoglobinuria)
• Fatigue
  
• Exercise intolerance, poor stamina 
  
• Muscle cramp, pain, stiffness, weakness