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6709: Lysosomal Disease Network Longitudinal Study of Pompe Disease

Study Summary

Please Note: The Rare Diseases Clinical Research Network will make every effort to enroll all the patients we can, but we cannot make any guarantees that we will be able to enroll everyone in a particular study who wants to participate.


Infantile-onset Pompe disease is an inherited disorder that is normally diagnosed within the first months of life. It is caused by lack of or defect in an enzyme (a special protein that carries out normal chemical reactions within the body) called acid alpha-glucosidase (GAA). GAA normally breaks down glycogen (stored sugar) in lysosomes (the part of the cell that digests food and other chemicals). Pompe disease is one of many lysosomal storage diseases (LSDs). LSDs are diseases caused by the malfunction of the lysosome or one of their digestive enzymes. Patients with Pompe disease cannot break down lysosomal glycogen. This causes glycogen to build up and damage cells throughout the body, especially in the heart and muscles.

Current treatment for Pompe disease involves enzyme replacement therapy (ERT). In this treatment, the drug alglucosidase alfa (Myozyme) is put into your blood. The drug provides a form of the GAA enzyme to replace the enzyme that is missing or not working properly in the patient's blood. This treatment has allowed babies to live longer and achieve developmental milestones.

In this study, researchers will learn about the patient's ability to tolerate ERT. Cross-Reactive Immunological Material (CRIM) is a measurement of natural GAA production. A patient's CRIM status (either positive or negative) is an important factor that affects how he or she responds to ERT with Myozyme. Children who produce some natural GAA are classified as CRIM+, while children who do not produce any natural GAA are classified as CRIM-.

Children who are CRIM+ generally tolerate ERT well. But children who are CRIM-, and some children classified as CRIM+, have a poor response to ERT. Patients who have a poor response to ERT have complications because their body sees Myozyme as "foreign" and triggers an immune response to try to remove it from the body. Treatments are currently being developed to stop this immune response and prevent complications from ERT.

We will enroll patients with Infantile Pompe disease in this longitudinal natural history (observational) study. The specific aims of this study are:

  1. To understand the developing natural history of Pompe disease, in both treated and untreated patients;
  2. To evaluate the success of immunosuppressive therapy for CRIM- patients and CRIM+ patients who are risk for complications of ER

About this Study

This is a longitudinal natural history study of Infantile Pompe disease. We will regularly collect and review medical information regarding the diagnosis of Pompe disease, health information and response to ERT for up to 3 years.

Targeted Enrollment

To be eligible to participate, you must:

  • Have a confirmed and documented diagnosis of Pompe disease (based on a low GAA enzyme activity and two confirmed GAA pathogenic variants).
  • Participant is less than 18 years of age at the time of enrollment.

This study also has a component that requires diagnosis through newborn screening. If you were not diagnosed by newborn screening you can still participate in the other parts of the study.

How to participate

In order to participate in a study, you must personally contact the study coordinator of any of the participating institutions by phone or by e-mail. Please use the information to the right to inquire about participation.