POMGNT2

The encoded protein is an O-linked mannose beta-1,4-N-acetylglucosaminyltransferase that synthesizes phosphorylated O-mannosyl trisaccharides on alpha-dystroglycan, enabling high-affinity binding to laminin and other extracellular matrix proteins. Mutations cause autosomal recessive muscular dystrophy-dystroglycanopathy, ranging from severe congenital forms with brain and eye anomalies to milder limb-girdle presentations. The gene shows low constraint against loss-of-function variants, consistent with its recessive inheritance pattern.