A Prospective Study to Observe & Describe Clinical Outcomes of Alglucosidase Alfa Treatment in Patients ≤6 Months of Age With Infantile-onset Pompe Disease (IOPD)

Primary Objective: To describe the effect of routine practice with alglucosidase alfa in patients with IOPD ≤6 months of age, on invasive ventilation-free survival after 52 weeks of treatment. Secondary Objectives: * To describe the effect of routine practice with alglucosidase alfa on invasive ventilation-free survival and survival at 12 and 18 months of age, as well as on change in left ventricular mass (LVM) Z score, Alberta Infant Motor Scale (AIMS) score, body weight, body length, and head circumference Z scores, and urinary glucose tetrasaccharide (Hex4), at Week 52 of treatment. * To describe the safety, tolerability, and immunogenicity of alglucosidase alfa in the routine practice of IOPD treatment.

Inclusion Criteria: * At the time of informed consent, participants must be ≤6 months of age, corrected for gestation if necessary. Gestational age \40 mmHg on room air, * Use of invasive (with intubation or tracheostomy) or noninvasive (no intubation or tracheostomy) ventilation at enrollment, for participants not having started ERT at enrollment, * Use of invasive or noninvasive ventilation at the time of ERT initiation, for participants having started ERT before enrollment. * Participants with major congenital abnormality including heart defect, neural tube defect, or Down syndrome that, in the opinion of the investigator, would preclude participation in the study or potentially decrease survival. * Participants with clinically significant organic disease other than signs/symptoms related to Pompe disease, including clinically significant cardiovascular, hepatic, pulmonary, neurologic, or renal disease, or other medical condition, serious intercurrent illness, or circumstance that, in the opinion of the investigator, would preclude participation or potentially decrease survival. * Previous or ongoing treatment in any clinical trial of, or managed access program for, avalglucosidase alfa or any other Pompe disease-specific therapy. The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.