Evaluation of the Safety and Efficacy of Infantile-onset Pompe Disease Gene Therapy Drug

Inclusion Criteria:

• Age < 6 months

• Patient has diagnosis of infantile onset Pompe disease

• The patient's legal guardian(s) must be able to understand the purpose and risks ofthe study and voluntarily provide signed and dated informed consent prior to anystudy-related procedures being performed.

Exclusion Criteria:

• Left ventricle ejection fraction (LVEF) < 40%;

• Patient who has AAV9 neutralizing antibody titer ≥ 1:100；

• Patient who has received enzyme replacement therapy (ERT) more than twice;

• Patient who has respiratory dysfunction before enrollment, including the bloodoxygen (O2) saturation level < 90%, or the partial pressure of carbon dioxide (PCO2)in venous blood > 55 mmHg, or PCO2 in arterial blood > 40 mmHg;

• Patient who has laboratory abnormalities of: creatinine > Upper Limit of Normal (ULN), hemoglobin < 90 g/L;

• Patient with congenital organ absence;

• Patient with a history of glucocorticoid allergy;

• Patient who is positive for human immunodeficiency (HIV) antibody, hepatitis Bsurface antigen, hepatitis C antibody, or treponema pallidum antibody;

• Patient who has participated in a previous gene therapy research trial;

• Patient who has any concurrent clinically significant major disease or any othercondition that, in the opinion of the investigator, makes the subject unsuitable forparticipation in the study.