What is Pompe disease?
Pompe disease is a genetic disorder in which complex sugar called glycogen builds up in the body’s cells. The disease results from the deficiency of an enzyme called acid alfa glucosidase (GAA), which breaks downs complex sugars in the body. This buildup occurs in organs and tissues, especially in muscles, causing them to break down.
Mutations in the GAA gene, which helps break down glycogen, cause this disorder.
What are the types of Pompe disease?
There are three types of Pompe disease:
- Classic infantile-onset appears within a few months of birth.
- Non-classic infantile-onset appears at about 1 year of age.
- Late-onset appears later in a child’s life, or even into the teen years or adulthood.
Who gets Pompe disease?
Since this is a genetic condition, the people who get this disease inherit it from a parent. It is common, however, that neither parent shows any symptoms. The disease is rare. In the United States, only 1 person in 40,000 is affected by Pompe disease. It can affect both males and females of all ethnic groups.
Symptoms and Causes
What are the symptoms of each type of Pompe disease?
Symptoms can be a bit different, depending on when the disease makes itself present. In infants, symptoms include the following:
- Weak muscles
- Poor muscle tone
- Enlarged liver
- Failure to gain weight and grow at the expected rate (failure to thrive)
- Trouble breathing
- Feeding problems
- Infections in the respiratory system
- Problems with hearing
- Motor skills delayed (such as rolling over and sitting)
- Muscles get steadily weaker
- Abnormally large heart
- Breathing problems
Late-onset type, which includes adult-onset:
- The legs and the trunk get steadily weaker.
- Breathing problems
- Enlarged heart
- Increasing difficulty in walking
- Muscle pain over a large area
- Loss of the ability to exercise
- Falling often
- Frequent lung infections
- Shortness of breath when the person pushes himself or herself
- Headaches in the morning
- Becoming tired during the day
- Losing weight
- Cannot swallow as easily as before
- Irregular heart beat
- Increased difficulty hearing
- Higher levels of creatine kinase (CK) , an enzyme that helps the body’s functions work and provides energy to cells
Diagnosis and Tests
How is Pompe disease diagnosed?
A blood sample is taken and enzymes in the blood are studied and counted. Also, there are tests such as sleep studies, breathing tests to measure lung capacity, and electromyography (a test that measures how well the muscles work).
A blood sample is taken and enzymes in the blood are studied and counted. Confirmation is made via DNA testing. Other tests include:
- Taking of a complete patient and family history
- Breathing tests to measure lung capacity (pulmonary function tests)
- Electromyography (a test that measures how well the muscles work) and MRIs
- Heart studies, including X-rays, electrocardiogram and echocardiogram
- Sleep studies
A prenatal diagnosis may be done for pregnant women at risk.
Management and Treatment
How is Pompe disease treated?
Enzyme replacement therapy (ERT) is an approved treatment for all Pompe patients. A drug called alglucosidase alfa is given intravenously (through the patient’s vein). It is a genetically engineered enzyme that acts like the naturally occurring acid alfa glucosidase enzyme.
Specialist teams (heart doctors, respiratory therapists, neurologists, etc.) can treat symptoms and offer supportive care for those with Pompe disease. Ask your doctors about details for each specific case.
What are the complications of Pompe disease?
Without treatment, infants with Pompe disease will die. Many of the people with Pompe disease have respiratory (breathing) problems, heart problems, and almost all are plagued with muscle weakness. Most people will have to use oxygen and wheelchairs at some point.
How can Pompe disease be prevented?
As this is a genetic disease it cannot currently be prevented. Supportive treatment and care are available.
Outlook / Prognosis
What is the outlook for people with Pompe disease?
Patients with either type of infantile-onset Pompe disease may have their lives prolonged with early detection and treatment. However, both of these types of Pompe disease often are fatal. Patients with classic infantile-onset type rarely live past 1 year of age. Patients with non-classic infantile–onset type may live to early childhood. Children with late-onset types of Pompe disease can live longer as the disease progresses more slowly.