Disease associated with this latter scenario are termed the dystroglycanopathies, and arise not through mutations in dystroglycan itself, but in a number of genes that are known or presumed to have function in the glycosylation of dystroglycan [[20][Muntoni, 2007 #2825]]. This evidence concerns the gene DAG1 and neuromuscular disease caused by qualitative or quantitative defects of alpha-dystroglycan.