Epsilon-sarcoglycan (SGCE) is a member of the sarcoglycan protein family []. Mutations in the SGCE gene cause myoclonus-dystonia syndrome []. The SGCE gene is maternally imprinted in matUPD7 lymphoblastoid cell lines and in leukocytes of myoclonus-dystonia syndrome patients [].The sarcoglycan family proteins are single pass transmembrane proteins that are part of the dystrophin-associated glycoprotein complex (DGC), a multiprotein complex that links the actin cytoskeleton to the extracellular matrix in cardiac and skeletal muscle []. The DGC can be classified biochemically into three subcomplexes: the cytoplasmic subcomplex (contains dystrophin, the dystrobrevins and the syntrophins), the dystroglycan subcomplex and the sarcoglycan subcomplex. The function of the sarcoglycan subcomplex is not clear. However, mutations in alpha-, beta-, gamma- and delta-sarcoglycan cause different forms of autosomal recessive limb girdle muscular dystrophies (LGMD) demonstrating its importance for normal muscle function [].
