Acid Maltase or Alpha Glucosidase (Pompe Disease)

Chemical Pathology

Notes

Acid Maltase Deficiency (AMD), also known as Pompes disease, is a rare genetic disorder that causes progressive weakness to the heart and skeletal muscles. This is due to a genetic mutation in the Acid Alpha-Glucosidase (GAA) gene. This mutation causes glycogen build up in the muscles, leading to damage and progressive weakening. As well as skeletal muscle, the muscles of the heart and respiratory system can also be affected. Cardiac or respiratory failure is the most common cause of death in patients with AMD.

AMD is estimated to affect about 1 in 40,000 births and can present in infancy (early/infant onset) or childhood/adulthood (late onset).

The infant onset form is the most severe, presenting with cardiomyopathy and severe, generalized muscular hypotonia, and usually results in death with the first two years of life.

Late onset AMD is associated with progressive proximal muscle weakness and respiratory insufficiency and disease progression is more variable.

Sample requirements

4 ml of blood taken into an EDTA tube

Storage/transport

Do not store. Samples should be collected early morning, Monday to Friday only and reach the laboratory before 12 o'clock midday to allow timely transfer to the assaying laboratory.

Required information

Relevant clinical details including reason for the test.

Turnaround times

Samples are sent for analysis to the Willink Laboratory, with results expected within 5 weeks.

Reference ranges

Alpha-glucosidase (Pompe diagnosis): 7.3-37 pmol/punch/hr

A control enzyme will also be tested for and reported alongside this result.

Further information

To learn more about Pompe disease visit: NORD

Page last updated: 17/05/2023