Evaluate Efficacy and Safety in Chinese Patients With Infantile-Onset Pompe Disease With One Year Alglucosidase Alfa Treatment

Inclusion criteria: * Subject's parents or legal guardians must provide written informed consent prior to any study-related procedures. * Documented onset of Pompe disease symptoms up to 12 months of age (corrected for gestation if born before 40 weeks); diagnosis of Pompe disease confirmed by acid alpha-glucosidase enzyme deficiency from any tissue source and acid alpha-glucosidase gene mutations. * Age 0-12 months at enrollment, defined as at the time of providing written informed consent. * Cardiomyopathy (abnormal left ventricular mass indices \[LVMIs\], measured by echocardiography, abnormal value is defined as ≥65 g/m2 for patients up to 12 months old) confirmed by cardiologist at study site. Exclusion criteria: * Patient who has previously been treated with acid alpha-glucosidase. * Patient who is participating in another clinical study using any investigational therapy. * Conditions/situations such as: * Clinical signs of cardiac failure with ejection fraction \< 40%. * Respiratory insufficiency (oxygen saturation \< 90% or carbon dioxide partial pressure \> 55 mm Hg \[venous\] or \> 40 mm hydrargyrum \[arterial\] in room air or any ventilator use). * Patients who are dependent on invasive or non-invasive ventilator support. * Patients with major congenital anomaly or clinically significant intercurrent organic disease unrelated to Pompe disease. * Patients not suitable for participation, whatever the reason, as judged by the Investigator, including medical or clin…