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. 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). Highest expression in heart and skeletal muscle. Low expression in brain, kidney, placenta, pancreas and lung. High expression in fetal brain. Also found in fetal lung, kidney and liver. Disulfide bonds are present. The disease is caused by variants affecting the gene represented in this entry. Belongs to the sarcoglycan beta/delta/gamma/zeta family. SGCB mutations in LGMD2E