POMGNT2 and neuromuscular disease caused by qualitative or quantitative defects of alpha-dystroglycan: In addition, several genes mutated in dystroglycanopathies contribute to the formation of a phosphorylated O-mannosyl-glycan, which is produced by consecutive addition of β-1,4-N-acetylglucosamine via GTDC2/AGO61 (refs 9, 10), of β-1,3-N-acetylgalactosamine via B3GALNT2 (refs 11, 12) and a phosphate group to carbon 6 of mannose via POMK1/SGK196 (ref. 11).