Myophosphorylase Deficiency

Myophosphorylase deficiency, known as McArdle disease, is a rare inherited disorder in which the muscles cannot properly use their energy reserves during exertion, which limits intense physical activity.

Common symptoms: early muscle fatigue, cramps and pain during exercise, and sometimes an improvement in symptoms after a brief rest at the start of activity.

Common causes: it is due to a genetic alteration that affects an enzyme responsible for releasing energy in the muscle, present from birth.

Which specialist treats it? At an early age the pediatrician guides the workup together with specialists in neuromuscular and metabolic diseases. If exercise repeatedly causes marked muscle pain and cramps, the sensible step is to request a professional evaluation.