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Pompe disease

Pompe disease (also known as acid-maltase disease and glycogen storage disease II) is a rare genetic disorder that causes progressive weakness to the heart and skeletal muscles. It is caused by mutations in a gene that makes an enzyme called acid alpha-glucosidase (GAA), which the body uses to break down glycogen, a stored form of sugar used for energy. The enzyme performs its function in intracellular compartments called lysosomes, which function as cellular clearinghouses. Lysosomes ingest multiple substances including glycogen, which is converted by the GAA into glucose, a sugar that fuels muscles.

In Pompe disease, mutations in the GAA gene reduce or completely eliminate this essential enzyme, which causes buildup that damages the muscles of the skeletal muscles and heart most seriously. The severity of the disease and the age of onset, which varies widely, are related to the degree of enzyme deficiency.

There are two forms of Pompe disease:

  1. Early onset (infantile form) is caused by the complete or near complete deficiency of GAA. Symptoms begin in the first months of life, with feeding problems, poor weight gain, trouble breathing, muscle weakness, enlarged heart, floppiness, and head lag. Many infants with Pompe disease also have enlarged tongues. Without enzyme replacement therapy, most babies die from cardiac or respiratory complications before their first birthday.
  2. Late onset (juvenile/adult) results from partial deficiency of GAA and can begin as early as the first decade of childhood or well into adulthood. Muscle weakness progresses to death from respiratory failure after several years. The heart is usually not involved.

Enzyme replacement therapy can help improve muscle tone and reduce glycogen storage in individuals with Pompe disease. The following drugs have been approved:

  • Alglucosidase alfa (Myozyme©) to treat infantile-onset Pompe disease
  • Lumizyme© to treat individuals of all ages with Pompe disease
  • Avalglucosidare alfa-ngpt (Nexviazyme©) for individuals age 1 and older with late-onset Pompe disease

How can I or my loved one help improve care for people with Pompe Disease?

Consider participating in a clinical trial so clinicians and scientists can learn more about Pompe disease and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with Pompe disease at

Where can I find more information about Pompe disease?

Information may be available from the following organizations and resources:

Acid Maltase Deficiency Association
Phone: 210-494-6144

Genetic and Rare Diseases (GARD) Information Center

Hide and Seek Foundation
Phone: 844-762-7672



Rare Disease Clinical Research Network

Content source: Accessed June 29, 2023.

The information in this document is for general educational purposes only. It is not intended to substitute for personalized professional advice. Although the information was obtained from sources believed to be reliable, MedLink, its representatives, and the providers of the information do not guarantee its accuracy and disclaim responsibility for adverse consequences resulting from its use. For further information, consult a physician and the organization referred to herein.

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