One page overview

This booklet provides referenced information to assist GPs and other medical professionals. McArdle disease should be managed by a specialist service, but this booklet can help with issues arising through primary care.

• McArdle disease is a very rare autosomal recessive disorder of muscle metabolism.

• Clinical Practice Guidelines for McArdle’s are published with open access (page 5).

• Specialist services are essential to achieve correct diagnosis and ensure good management.

• Genetic confirmation is necessary to avoid potentially damaging misdiagnosis.

• There is an inability to utilize muscle glycogen.

• Maximal isometric activity must be ceased by about 6 seconds to avoid risk of muscle contracture.

• An energy crisis occurs in all activity, severe in the first 10 minutes and throughout intense activity.

• This causes premature fatigue, exaggerated heart rate, pain, muscle spasm and can lead to fixed contracture.

• Diagnosis is often delayed about 20 years, during which time muscle damage or atrophy may occur.

• Patients diagnosed in childhood may learn to manage their condition and be less severely affected – although always at risk of contracture.

• Regular exercise is essential to enhance aerobic metabolism and reduce the risk of muscle damage.

• Patients need to be able to recognize the signs that urgent hospital attendance is required.

• Patients are at risk of some concomitant conditions, but not all issues are related.

• Sharing with other patients through support groups can help considerably.