Electron microscopy is used to classify sub-types of the vacuoles in which glycogen accumulates. Histopathological examination of muscle is not necessary to establish diagnosis. There is currently no effective medical treatment for the underlying disorder. Symptomatic treatment of cardiac and respiratory failure is available but does not significantly alter the clinical course. There is anecdotal evidence that a high-protein diet can provide temporary improvement but does not alter disease course.
Animal trials using enzyme replacement therapy are ongoing.
A clinical geneticist is advised to counsel families regarding risk to future pregnancies. Since all patients require an EMG, involve the neurology service. Experienced interpretation of ECHO findings is necessary. As noted above, alterations in diet do not provide lasting improvement. Weakness can contribute to feeding difficulty in all patients.