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.
Most strongly expressed in skeletal muscle. Also expressed in cardiac muscle and, at much lower levels, in lung. In the fetus, most abundant in cardiac muscle and, at lower levels, in lung. Also detected in liver and kidney. Not expressed in brain.
Involvement in disease
Defects in SGCA are the cause of limb-girdle muscular dystrophy type 2D (LGMD2D) [MIM:608099]; also known as Duchenne-like muscular dystrophy autosomal recessive type 2 or severe childhood autosomal recessive muscular dystrophy (SCARMD). LGMD2D is an autosomal recessive degenerative myopathy characterized by progressive muscle wasting from early childhood with loss of independent ambulation by teenage years. Muscle biopsy shows necrosis, decreased immunostaining for alpha sarcoglycan, and adhalin deficiency. The phenotype is less severe than LGMD2C.