Beta-sarcoglycan (SGCB) (SGCB)

Beta-sarcoglycan is a 43 kDa transmembrane glycoprotein that serves as a core component of the sarcoglycan complex, which is part of the larger dystrophin-associated protein complex (DAPC) (UniProt: P52704). This complex is essential for maintaining the mechanical stability of the sarcolemma in both skeletal and cardiac muscle fibers by linking the internal actin cytoskeleton to the extracellular matrix (NCBI Gene: 6443). Mutations in the SGCB gene lead to Limb-Girdle Muscular Dystrophy Type 2E (LGMD2E), also known as LGMDR4, a severe and progressive neuromuscular disorder (OMIM: 600900). In the absence of functional beta-sarcoglycan, the entire sarcoglycan sub-complex often fails to assemble or stabilize, leading to membrane fragility and muscle fiber necrosis. Therapeutic interventions currently under investigation, such as the gene therapy bidridistrogene fexaparvovec (SRP-9003), aim to deliver a functional copy of the SGCB gene using adeno-associated virus (AAV) vectors to restore protein expression and muscle integrity (Sarepta Therapeutics, 2023). These treatments target the underlying genetic cause to prevent disease progression and improve motor function in affected patients.

Other names

Sarcoglycan beta43 kDa dystrophin-associated glycoprotein43DAGLimb-girdle muscular dystrophy type 2ELimb-girdle muscular dystrophy R4

Gene replacement therapy via adeno-associated virus (AAV) vector delivery of a functional SGCB transgene