Expanded Access for ATB200/AT2221 for the Treatment of Pompe Disease

Inclusion Criteria: 1. Subject must have a diagnosis of Pompe disease based on documentation of one of the following: 1. deficiency of GAA enzyme 2. GAA genotyping 2. Patient does not currently qualify for an Amicus sponsored on-going clinical trial or is declining on currently approved ERT (e.g. Myozyme) 3. The patient must be willing to receive treatment with ATB200/AT2221 via this program, which includes signing an authorization form for sharing clinical data with Amicus Therapeutics, and its agent Early Access Care LLC. Exclusion Criteria: 1. Patient, whether male or female, is planning to conceive a child during the treatment program. 2. Patient has a hypersensitivity to any of the excipients in ATB200, alglucosidase alfa, or AT2221 3. Patient has a medical or any other extenuating condition or circumstance that may, in the opinion of the investigator, pose an undue safety risk to the subject or compromise his/her ability to comply with or adversely impact protocol requirements. 4. Patient has received any gene therapy at any time. 5. Concomitant use of miglitol (eg, Glyset), non-AT2221 form of miglustat (eg, Zavesca), acarbose (eg, Precose or Glucobay), voglibose (eg, Volix, Vocarb, or Volibo)