The proposed human clinical trial is a phase I, double-blind randomized protocol with injection of rAAV1.tMCK.hαSG gene vector into muscle. Two cohorts of subjects with LGMD2D(alpha-sarcoglycan deficiency), each with proven mutations will undergo gene transfer. A minimum of three subjects will be enrolled into each cohort. The first cohort will receive a total of 1.5 ml volume of study agent in two to six separate injections into the selected muscle (extensor digitorum brevis) or other muscle if more appropriate considering the individual patient) with a dose of 3.25 X 10 to the 11 vg in 1.5 ml. The anatomical midline point of the muscle will be identified on the skin and 2 to 6 vector injections will be distributed in the direction of an X. The second cohort will receive the same dose delivered to muscle according to the same paradigm. In each cohort, only one extremity will receive vector with transgene while the opposite extremity will be injected with placebo. On the day of the vector infusion, 4 hours before gene transfer, patients will receive intravenous methylprednisolone 2.0 mg/kg (not to exceed 1 gm total), with repeat doses on two consecutive mornings. The methylprednisolone is specifically given to diminish the immediate inflammation from the needle injection, which is known to arouse an inflammatory reaction and could contribute to bringing antigen presenting cells to the site of vector delivery. We have previously demonstrated that this treatment enhances gene expression by at least 2-fold (Included as part of BB-IND-12936 for minidystrophin gene transfer).