Safety Study of Recombinant Adeno-Associated Virus Acid Alpha-Glucosidase to Treat Pompe Disease

Inclusion Criteria: * Male or female subjects 2-18 years of age. * Have a diagnosis of Pompe, as defined by protein assay, DNA sequence of the acid alpha-glucosidase gene and clinical symptoms of the disease. * Using assisted ventilation at baseline. Mechanical Ventilation is defined as any use of ventilation support, (including but not limited to BiPAP, CPAP), a minimum of 1 hours per day. * Willing to discontinue aspirin, aspirin-containing products and other drugs that may alter platelet function, 7 days prior to dosing, resuming 24 hours after the dose has been administered. Exclusion Criteria: The subject must not: * Have required acute, as distinguished from long-term, maintenance or chronic suppressive, oral or intravenous antibiotic therapy for a respiratory infection within 15 days prior to baseline screening. * Have required oral or systemic corticosteroids within the last 15 days prior to baseline screening. * Have a platelet count less than 75,000/ cu mm. * Have an INR greater than 1.3. * Serological evidence of hepatitis B, hepatitis C, or HIV positive. * Be currently or within the past 30 days participating in any other research protocol involving investigational agents or therapies. * Have received gene transfer agents within the past 6 months. * Have history of platelet dysfunction, evidence of abnormal platelet function at screening or history of recent use of drugs that may alter platelet function which the subject is unable/unwilling to discontinue for …