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Learning About Pompe

What is Pompe disease and what can be expected?

Pompe disease is a rare genetic disorder that can be inherited from both parents. It affects people all around the world, no matter what age or gender. For many years, scientists and clinicians believed that 1 in 40,000 people were living with Pompe disease. However, as diagnoses increase and newborn screening becomes more common, this estimate is likely to change.

Twenty years ago, there were few treatment options for people who developed Pompe disease symptoms. Today, there’s a much greater understanding of how Pompe disease can affect people over time and how it can be managed.


When we share knowledge that helps empower decision making—we Pompe Together.

Common FAQs about Pompe disease

What is the cause of Pompe disease?

In Pompe disease, the body is missing or has low levels of an enzyme called “acid alpha-glucosidase” (or GAA). GAA works in tiny cellular compartments called “lysosomes” to break down a complex sugar called “glycogen” into a simple sugar called “glucose.” The body uses glucose for energy.

What happens when too much glycogen builds up in the body?

Pompe disease is a multisystem disorder that has varying rates of progression, age of onset, organ involvement, symptoms, and overall severity.

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When GAA isn’t working properly, glycogen can build up in tissues throughout the body, such as in smooth and skeletal muscles, the central nervous system, or the heart.

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Glycogen is a thick, sticky substance that can cause loss of muscle function as it accumulates.

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Skeletal muscles are often affected by Pompe disease. Excess glycogen in muscle cells can lead to weakness that worsens over time.

What are other names for Pompe disease?
  • Acid maltase deficiency, acid maltase deficiency disease, or AMD
  • Alpha-1,4-glucosidase deficiency, deficiency of alpha-glucosidase
  • GAA deficiency
  • Glycogen storage disease type II, GSD II, or GSD2
  • Pompe’s disease

What are common symptoms of Pompe disease?

Common symptoms include muscle weakness that affects movement and breathing difficulties that may worsen over time. Other parts of the body can be affected as well.

Brain

Brain: Having too much glycogen in the nervous system can make it hard to remember things, learn new information, focus, or make decisions.

Vascular system

Vascular system: Most people with late-onset Pompe disease don’t usually have heart problems. However, some may experience issues like bleeding, blood clots, or problems with their blood vessels.

Respiratory system:

Respiratory system: When the muscles around the ribs and in the diaphragm get weak, it can make it hard to breathe and sleep. Some people might need help from a ventilator machine to breathe properly. Severe breathing problems can become life-threatening.

Gastrointestinal system

Gastrointestinal system: Pompe disease can affect parts of the digestive system, like the esophagus, stomach, and intestines. This might cause problems like not gaining enough weight, stomach aches, nausea, or vomiting.

Skeletal muscles

Skeletal muscles: Many people with Pompe disease have weak and shrinking muscles throughout their body. This makes it hard for them to walk, go up stairs, or stand up from a chair or the floor. They might also fall often, feel very tired, or have pain all the time.

Can symptoms from Pompe disease vary from one person to the next?

Depending on the type of GAA gene someone inherits, Pompe disease can affect the body in different ways—influencing how much functioning GAA a person has, when symptoms become noticeable, and how quickly they progress.

What is infantile-onset Pompe disease (IOPD)?

Pompe disease can be detected at birth in states where newborn screenings test for the disease. It can also be diagnosed when infants younger than 12 months develop symptoms; this type of Pompe disease is called infantile-onset Pompe disease (IOPD).


In IOPD, babies may have less than 1% of functioning GAA in cells, resulting in symptoms that may appear within one to three months of life and become serious quickly. These babies need treatment right away in order to survive.

 

Symptoms may vary but can include:

  • Enlarged heart and difficulty breathing
  • Feeding problems, poor weight gain, and failure to thrive
  • Droopy body that’s similar to a rag doll
What is late-onset Pompe disease (LOPD)?

When symptoms develop after one year, it’s often called late-onset Pompe disease (LOPD). LOPD, or delayed-onset Pompe disease, refers to people who are diagnosed at any age from early childhood throughout adulthood. In LOPD, someone may have anywhere from about 1% to 30% of functioning GAA in their cells.

Lower levels of functioning GAA can cause symptoms that appear earlier in life and progress faster than in people with higher levels of GAA.

Is Pompe disease testing available?

Testing is available, but getting diagnosed can take time. The earlier someone is diagnosed with Pompe disease, the sooner they can get the right treatment. Newborns with IOPD are often diagnosed within the first few months of life based on signs, symptoms, and the results of laboratory testing. Pompe disease diagnosis can take much longer for older children and adults.

Are delays in diagnosis common?

Some states and countries offer screening for Pompe disease at birth. In other cases, getting a correct diagnosis can take years—and many doctor visits—for children and adults with LOPD. There are two big reasons for this delay:

 

  1. The disease is very rare and it’s not top of mind for some doctors.

  2. Some of the symptoms of Pompe disease are signs of other, more common conditions. In fact, up to about 50% of people with Pompe disease are incorrectly diagnosed with something else first.

 

Going to a treatment center that specializes in rare diseases may help someone with puzzling symptoms get a diagnosis sooner.

 

Here’s a list of places to start.

Delays in diagnosis are common
What tests for Pompe disease are available?

Once a doctor thinks someone might have Pompe disease, the tests to diagnose it are fairly straightforward. 

A skin or muscle biopsy

A skin or muscle biopsy is when a small tissue sample is taken to measure levels or activity of the GAA enzyme in muscle cells. If the results are low, it could mean Pompe disease. 

Blood and urine tests

Blood and urine tests can show signs of glucose buildup and muscle damage related to Pompe disease.


Genetic testing

Genetic testing (also used in newborn screening in some states and countries) can be used to diagnose Pompe disease. It may even be helpful in family planning if another relative has already been diagnosed.

A chest x-ray and electrocardiogram (ECG) may be used to look for signs of heart disease in possible cases of infantile-onset Pompe disease.

 

Understand how a genetic counselor could help with the diagnosis journey.

How is Pompe disease managed and why does it take a care team?

Because of the many challenges that go along with Pompe disease, it often helps to have a team of doctors, therapists, and counselors to support patients and their caregivers.


Find out who’s on the healthcare team.

How is Pompe disease treated today?

Today, the main treatment for Pompe disease is enzyme replacement therapy (ERT). By replacing the missing GAA enzyme, ERT can help to stop the buildup of glycogen and slow down progressive muscle weakness. ERT is given to patients through an intravenous (into the vein) infusion every other week.


There is evidence that ERT has helped children with infantile-onset Pompe disease live longer. Most people with the late-onset form experience slowed progression while using ERT, although the benefits of treatment may decrease over time.


One challenge with ERT is that it can’t always reach all the places in the body that need help. Another issue is that some people may develop an immune system reaction that fights the treatment, making it less effective.


Even with ERT, some people may continue to have symptoms and may experience disease progression over time.

Current treatment methods
What supportive care options can help people living with Pompe disease?

A range of supportive care options can help address individual needs and improve quality of life.

Therapists

Therapists can help with trouble breathing, weak muscles, eating the right food, and difficulty speaking. They can also provide tools like canes or walkers to make moving around easier.

Counselors

Counselors can offer educational and emotional support. Genetic counselors can provide information about Pompe disease, while other counselors talk to both patients and caregivers to help them cope with some of the big life changes that can come with Pompe disease.

Find out where to turn for emotional support.

Researchers are studying the potential of gene therapy
Researchers are studying the potential of gene therapy
Looking Ahead

What research is underway for Pompe disease, including gene therapy?

Scientists are working towards developing new treatment options to correct the defective (mutated) GAA gene, which causes Pompe disease. This area of research is known as gene therapy, and there are already special investigational studies underway called clinical trials.

Although these gene therapy treatments are not approved yet, if successful, they could help muscles work the way they’re supposed to in people with Pompe disease.