Component of the sarcoglycan complex, a subcomplex of the dystrophin-glycoprotein complex which forms a link between the F-actin cytoskeleton and the extracellular matrix. Interacts with FLNC and DAG1. Cross-link to form 2 major subcomplexes: one consisting of SGCB, SGCD and SGCG and the other consisting of SGCB and SGCD. The association between SGCB and SGCG is particularly strong while SGCA is loosely associated with the other sarcoglycans (By similarity). Most strongly expressed in skeletal and cardiac muscle. Also detected in smooth muscle. Weak expression in brain and lung. Glycosylated. Disulfide bonds are present. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the sarcoglycan beta/delta/gamma/zeta family. SGCD mutations in LGMD2F/CMD1L