A number of muscular dystrophies (MD) are associated with the defective glycosylation of α-dystroglycan and many of which are now known to result from mutations in a number of genes encoding putative or known glycosyltransferases. These diseases include severe forms of congenital muscular dystrophy (CMD) such as Fukuyama type congenital muscular dystrophy (FCMD), Muscle–Eye–Brain disease (MEB) and Walker–Warburg syndrome (WWS), which are associated with brain and eye abnormalities. The defective glycosylation of α-dystroglycan in these disorders leads to a failure of α-dystroglycan to bind to extracellular matrix components and previous attempts to model these disorders have shown that the generation of fukutin and Pomt1 deficient knockout mice results in early embryonic lethality due to basement membrane defects.