The primary objective of this study is safety and endpoints will include hematology, serum chemistry, urinalysis, immunologic response to rAAV1 and follistatin, and reported history and observations of symptoms. Efficacy measures will be used as secondary outcomes and include the distance walked on the 6MWT, functional tests by PT, life quality questionnaire, MRI, EIM, and muscle biopsy. Subject will have follow up visits on days 7, 14, 30, 45, 60, 90, 180 and 9,12, 18 and 24 months post-gene transfer.