Dystroglycan is a essential protein formuscles to function correctly, and helps to connect the interior framework of muscle cells with the external matrix of molecules. B4GAT1 (formerly known as B3GNT1) is a beta-1,4-glucuronyltransferase with activity toward monomeric alpha- and beta- xylopyranosides. B4GAT1 forms short carbohydrates on the surface of the part of dystroglycan that sits on the surface of cells. These carbohydrates can then be elongated by another glycosyltransferase called LARGE with the ligand-binding heteropolysaccharide [, ]. Mutations in the B4GAT1 genes cause Walker-Warburg syndrome, a genetically heterogeneous form of congenital muscular dystrophy with significant brain and ocular involvement [, ].
