POMT1 and neuromuscular disease caused by qualitative or quantitative defects of alpha-dystroglycan: Hypoglycosylation of α-dystroglycan (α-DG) resulting from deficiency of protein O-mannosyltransferase 1 (POMT1) may cause severe neuromuscular dystrophies with brain and eye anomalies, named dystroglycanopathies.