General Condition Information
- Acid Maltase deficiency
- Glycogen storage disease type II (Pompe disease)
- Glycogen storage disease type II (Pompe)
- Glygogen storage disorder type II
- Pompe disease (Glycogen storage disease type II)
- Pompe Disease, infantile onset
- Pompe diseases
What is Pompe disease
Pompe disease is an inherited (genetic) condition that prevents the body from processing sugars properly. Pompe disease is named for the first doctor to describe the condition.
Your body stores extra sugar as glycogen, which it then uses for energy. An enzyme called acid alpha-glucosidase (GAA) breaks down glycogen to help provide that energy. This process takes place in lysosomes, which are special compartments in your cells that process many nutrients your body needs.
Pompe disease develops when GAA is present at low levels or is not built correctly. This makes it harder for lysosomes to break down glycogen. The build-up of glycogen affects the function of cells in the body’s organs, especially in the muscles.
There are three types of Pompe disease that differ in signs and symptoms and age of onset. These three types are known as classic infantile-onset, nonclassic infantile-onset, and late-onset. The type your baby has depends on how well their body can break down glycogen.
Without treatment, high levels of glycogen can damage the heart, liver, and muscles. This damage leads to the signs and symptoms of the condition.
Newborn Screening and Follow-Up
Newborn screening for Pompe disease is done using a small amount of blood collected from your baby’s heel. To learn more about this process, visit the Blood Spot Screening page.
During screening, a special machine measures how much of a certain enzyme (called acid alpha-glucosidase or GAA) is in your baby’s blood. This enzyme is responsible for breaking down glycogen. Babies with a low level of this enzyme might have Pompe disease.
If your baby’s blood spot screening result for Pompe disease is out-of-range, your baby’s health care provider will contact you. Together, you will discuss next steps and follow-up plans.
An out-of-range screening result does not mean that your baby definitely has the condition. It does mean that your baby needs more follow-up testing. To learn more about screening results, visit the Blood Spot Screening Results page.
Your baby may need the following tests after an out-of-range screening result:
- Heart exam that may include a chest X-ray or an echocardiogram
- Blood and/or urine tests
- Genetic testing using a blood sample
You should complete any recommended follow-up testing as soon as possible. Babies with this condition can have serious health problems soon after birth if they are not diagnosed and treated quickly.
False-positive newborn screening results for this condition may happen. Some babies with positive newborn screening results for Pompe disease have “pseudodeficiency.” Pseudodeficiency means that a baby’s enzyme levels are low on the screening but are normal in their body. These babies do not have and will never develop Pompe disease.
Newborn screening helps babies lead healthier lives. If your baby has an out-of-range result, follow up with your health care provider quickly. It is important to follow their instructions. Your baby may need to get treatment right away, even if they are not showing signs or symptoms. In some cases, your baby’s health care provider may decide it is best to watch (monitor) your baby to decide next steps. Careful monitoring and early treatment will help your baby stay as healthy as possible.
Signs of Pompe disease can appear shortly after birth (particularly in the classic infantile-onset form). Other forms of Pompe disease (nonclassic infantile-onset and late-onset forms) may not appear until later in infancy, adolescence, or adulthood.
Signs of the condition may include the following:
- Heart problems (cardiomyopathy)
- Muscle weakness
- Floppy arms and legs (hypotonia)
- Failure to gain weight and grow (failure to thrive)
- Breathing problems
- Hearing problems
Pompe disease is caused by a change in the GAA gene. This gene gives the body instructions for making an enzyme that breaks down a certain type of sugar, called glycogen.
A changed GAA gene prevents the body from breaking down glycogen properly. Glycogen then builds up in special processing compartments of the cells called lysosomes. When lysosomes get too full, cells do not function properly. In Pompe disease, the cells of the muscles are most affected.
- Pompe disease is an autosomal recessive condition. Babies inherit the condition when each parent passes down a nonworking GAA gene to their baby. Only babies with two nonworking GAA genes—one from the mom and one from the dad—have this condition.
- People with one working copy and one nonworking copy of the GAA gene are called carriers.
- Carriers do not have or develop the condition. However, they may pass down a nonworking copy of the gene to their children.
- If two parents are carriers of a nonworking copy of the GAA gene, they have a 1 in 4 chance of having a child with Pompe disease.
- Carriers for Pompe disease often do not know they are carriers before having a child with the condition. In most cases, families have no history of the condition until the birth of a child with Pompe disease.
- Parents who already have a child with Pompe disease still have a 1 in 4 chance of having another child with Pompe disease. This 1 in 4 chance stays the same for all future children.
- Genetic counselors and medical geneticists can help families learn about this condition and the chance of having children with it. Visit the National Society of Genetic Counselors to find a genetic counselor and the American College of Medical Genetics and Genomics to find a medical geneticist.
Treatment and Management
It is important to talk to your health care provider about which treatment(s) are best for your baby. The goal of treatment is to prevent the health problems caused by this condition.
Treatments may include the following:
- Enzyme replacement therapy (ERT)
- Physical therapy
- Respiratory therapy and breathing support
- Nutritional and feeding support
Children who receive early and ongoing treatment for Pompe disease can live longer and have better growth.