Clinical Exploration of Adeno-associated Virus (AAV) Expressing Human Acid Alpha- Glucosidase (GAA) Gene Therapy for Patients With Infantile-onset Pompe Disease

Inclusion Criteria: * The patient's legal guardian(s) must be able to understand the purpose and risks of the study and voluntarily provide signed and dated informed consent prior to any study-related procedures being performed; * The patient must be no older than 6 months; * The patient must be diagnosed with infantile-onset Pompe disease. Exclusion Criteria: * Class IV patient based on Modified Ross Heart Failure Classification for Children; * Aspartate aminotransferase (AST), alanine aminotransferase (ALT) \> 3x upper limit of normal (ULN), alkaline phosphatase (ALP) \> 2x ULN (with the exception of liver abnormalities related to Pompe disease); * Patient has severe organ dysfunction, such as liver and kidney failure (Liver failure: patients may have liver failure syndrome, including fatigue, severe gastrointestinal symptoms; clinical examination found prolonged prothrombin time, prothrombin activity less than 40%; Neuropsychiatric symptoms, such as restlessness, changes in personality and behavior, lethargy, coma, etc.; Toxic tympanic bowel, ascites, multiple organ dysfunction, etc.; hyperalbuminemia exceeding 171 μmol/L, hypoalbuminemia. Renal failure: creatinine exceeding 110 μmol/L, or glomerular filtration rate less than 100 mL/min), congenital/acquired encephalopathy, etc.; * Patient with congenital organ absence; * Patient with primary immunodeficiency; * Patient who is positive for human immunodeficiency virus (HIV) antibody, hepatitis B surface antigen, hepatitis C antibody, or treponema pallidum antibody; * Patient with a history of glucocorticoid allergy； * Patient who has participated in a previous gene therapy research trial; * Patient who has any concurrent clinically significant major disease or any other condition that, in the opinion of the Investigator, makes the subject unsuitable for participation in the study.