POMT2 and neuromuscular disease caused by qualitative or quantitative defects of alpha-dystroglycan: Given the severe effect on skeletal muscle function in dystroglycanopathy patients with mutations in either POMT1 or POMT2, we developed a mouse model in which Pomt1 was specifically deleted in skeletal muscle, which provides a mechanism to understand the role of O-mannosylated α-DG in skeletal muscle development and disease.