SGCG encodes gamma-sarcoglycan, one of several sarcolemmal transmembrane glycoproteins that interact with dystrophin (Fig. 1 and Table 3). The dystrophin-glycoprotein complex (DGC) spans the sarcolemma and is comprised of dystrophin, syntrophin, alpha- and beta-dystroglycans and sarcoglycans (alpha, beta, gamma, epsilon) (Blake et al., 2002). Several forms of muscular dystrophy are caused by defects in the function and assembly of the DGC (Blake et al., 2002). Dystrophin and members of the DGC including sarcoglycans are found in the brain where they participate in macromolecular assemblies that anchor receptors to specialized sites within the membrane. In neurons, dystrophin and the DGC participate in the postsynaptic clustering and stabilization of some inhibitory GABAergic synapses (Waite et al., 2009). Polymorphisms located within epsilon-sarcoglycan results in a neurogenic movement disorder, myoclonus-dystonia syndrome, which suggests that members of the sarcoglycan family of glycoproteins (including gamma-sarcoglycan) play a key role in dopaminergic neurotransmission (Peall et al., 2013). In addition, polymorphisms within epsilon-sarcoglycan are associated with a psychiatric phenotype consisting of compulsivity, anxiety and alcohol dependence in addition to the characteristic motor phenotype (Hess et al., 2007; Peall
