SGCG and sarcoglycanopathy: Nineteen patients with sarcoglycanopathies were found to have two mutations in SGCA, SGCB, or SGCG, but 3 patients were found to have only one mutation in SGCA or SGCB. The mutations identified in SGCA, SGCB, SGCG, FKRP, and DMD were of various types that were comprised of insertions/deletions (indels), single nucleotide variants (SNV), and deletions or duplications of one or more exons.