Defect in glycosylation that causes muscular dystrophy.

Muscular dystrophies are a diverse group of inherited disorders characterized by progressive muscle weakness and wasting. The dystrophin-glycoprotein complex is composed of alpha-, beta-dystroglycan (DG), dystrophin and some other molecules. alpha- and beta-DG stabilize the sarcolemma by acting as an axis through which the extracellular matrix is tightly linked to the cytoskeleton. The relative molecular weights of alpha-DG differ in different tissues as a result of differential glycosylation. New findings indicate that disrupted glycosylation of alpha-DG results in a loss of ligand binding, giving rise to both progressive muscle degeneration and abnormal neuronal migration in the brain. This article discusses methods, including purification of alpha-DG and glycosyltransferase assays involved in alpha-DG glycosylation.