Pompe disease, also called Glycogen storage disease type II, is an autosomal recessive metabolic disorder which damages muscle and nerve cells throughout the body.
It is caused by an accumulation of glycogen in the lysosome due to deficiency of the lysosomal acid alpha-glucosidase enzyme. It is the only glycogen storage disease with a defect in lysosomal metabolism, and the first glycogen storage disease to be identified, in 1932 by the Dutch pathologist J. C. Pompe. The build-up of glycogen causes progressive muscle weakness (myopathy) throughout the body and affects various body tissues, particularly in the heart, skeletal muscles, liver and the nervous system.
Pompe’s disease is divided in:
It usually comes to medical attention within the first few months of life. The usual symptoms are:
- Floppy baby appearance, delayed motor milestones and feeding difficulties.
- Moderate hepatomegaly may be present.
- Facial features include macroglossia, wide open mouth, wide open eyes, nasal flaring (due to respiratory distress), and poor facial muscle tone.
Late onset form
This form differs from the infantile principally in the relative lack of cardiac involvement. Some symptoms are:
- Impaired cough
- Recurrent chest infections
- Progressive muscle weakness
- Delayed motor milestones
- Difficulty swallowing or chewing and reduced vital capacity.
Cure and Therapy
Cardiac and respiratory complications are treated symptomatically. Physical and occupational therapy may be beneficial for some patients. Alterations in diet may provide temporary improvement but will not alter the course of the disease. Genetic counseling can provide families with information regarding risk in future pregnancies.