To collect uniform and meaningful data on patients with Pompe disease who experience anaphylaxis, severe allergic reactions, and/or signals of severe cutaneous and/or systemic immune complex-mediated reactions following treatment with alglucosidase alfa.

Inclusion Criteria:

• The patient must be enrolled in the Pompe Registry;
• Provide a signed patient information and authorization form;
• Have a confirmed diagnosis of Pompe disease (confirmation of diagnosis is defined as documented GAA enzyme deficiency from any tissue source and/or documentation of 2 GAA gene mutations);
• Be naïve to and plan to be treated with alglucosidase alfa at or prior to enrollment, or are being treated with alglucosidase alfa.

Exclusion Criteria:

• Patients will be excluded if they have received an investigational drug (excluding alglucosidase alfa) within 30 days prior to signing a Safety Sub-Registry Patient Information and Authorization form, or if they are taking or plan to take any investigational product while enrolled in the Safety Sub-Registry.

Patients who are enrolled in the Pompe Registry will be enrolled in this sub-registry include patients with infantile-onset Pompe disease, as well as those with late-onset Pompe disease.

An approximately equal proportion of currently treated and treatment-naïve patients is targeted for enrollment at each site.