BBM-L101 Gene Therapy in Participants With LGMD2D/R3

This phase 1 study will evaluate a single intravenous infusion of BBM-L101, an investigational AAV-based gene therapy designed to deliver a functional SGCA gene, in ambulatory children aged 4 to \<13 years with genetically confirmed SGCA-related limb-girdle muscular dystrophy (LGMD2D/R3). The primary objective is to assess safety and tolerability. The study will also explore muscle protein expression, serum creatine kinase, motor function, biodistribution/vector shedding, and immune responses. Participants will be followed for 52 weeks in the main study and through 5 years after infusion for long-term safety and efficacy.