What Is Pompe Disease?

Pompe disease in an inherited glycogen storage disorder

Heng Phaly, 65, holds her two-year-old grandson David. Credit: Jerry Redfern / Contributor / Getty Images

Pompe disease, also known as glycogen storage disease type II (GSD-II) or acid maltase deficiency, is one of 49 known lysosomal storage disorders. The name Pompe disease comes from the Dutch pathologist J.C. Pompe, who first described an infant with the disease in 1932. Pompe disease affects an estimated 5,000 to 10,000 people worldwide. In the United States, it is estimated to affect 1 per 40,000 people.

Pompe disease is caused by a deficiency or complete lack of an enzyme called acid alpha-glucosidase. If this enzyme doesn’t work properly, glycogen, a complex sugar, builds up in the body’s cells and causes organ and tissue damage. This buildup mainly affects the body’s muscles, leading to widespread muscle weakness. This enzyme deficiency can become life-threatening when the breathing and heart muscles are affected. The condition is genetic, and both parents must carry the mutated gene for their child to inherit it.

There are two forms of Pompe disease — infantile-onset and late-onset — both of which cause muscle weakness. How the disease progresses depends on how early it begins.

Infantile-Onset Pompe Disease

Infantile-onset is considered the severe form of Pompe disease. The condition usually appears within the first few months of life. Infants are weak and have trouble holding up their heads.

Their heart muscles become diseased and their hearts become enlarged and weak. They may also have large, protruding tongues and an enlarged liver. Other symptoms include:

  • Failure to grow and gain weight (failure to thrive)
  • Heart defects and irregular heartbeat
  • Difficulty breathing which may include fainting spells
  • Trouble feeding and swallowing
  • Missing developmental milestones like rolling over or crawling
  • Problems moving arms and legs
  • Hearing loss

The disease progresses rapidly, and children usually die of heart failure and respiratory weakness before their first birthday. Affected children may live longer with appropriate medical interventions.

Late-Onset Pompe Disease

Late-onset Pompe disease usually starts with symptoms of muscle weakness which can begin anytime from early childhood through to adulthood. Muscle weakness affects the lower half of the body more than the upper extremities. The disease progresses more slowly than the infantile form, but individuals still have a shortened life expectancy.

Life expectancy depends on when the condition begins and how quickly symptoms progress. Symptoms such as difficulty walking or climbing stairs begin and progress slowly over the years. Like with early-onset, people with late-onset may also develop breathing problems. As the disease progresses, individuals become wheelchair dependent or bedridden, and may require a respirator to breathe.

How Is Pompe Disease Diagnosed?

Pompe disease is usually diagnosed after symptom progress. In adults, Pompe disease may be confused with other chronic muscle diseases such as multiple sclerosis. If your doctor suspects Pompe disease, they may examine the activity of the enzyme acid alpha-glucosidase in cultured skin cells. In adults, a blood test can be used to determine a reduction or absence of this enzyme.

Treating Pompe Disease

An individual with Pompe disease will need specialized medical care from geneticists, metabolic specialists, and neurologists. Many individuals find a high-protein diet to be helpful, along with extensive daily exercise. Frequent medical evaluations are necessary as the disease progresses.

In 2006, the European Medicines Agency (EMEA) and the U.S. Food and Drug Administration (FDA) both granted marketing approval for the drug Myozyme to treat Pompe disease. In 2010, Lumizyme was approved. Myozyme is for patients younger than 8 years old while Lumizyme is approved for those over the age of 8. Both drugs replace the missing enzyme, therefore helping reduce the symptoms of the condition. Both Myozyme and Lumizyme are delivered intravenously every two weeks.


Overview of Pompe DiseasePompe Community. 2005. Genzyme Corporation. 29 Nov 2007.

AMD - Acid Maltase Deficiency - Pompe Disease. 1997. Acid Maltase Deficiency Association. 29 Nov 2007.

National Organization for Rare Diseases (NORD). Pompe Disease (2013).

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