Molecular characteristics

Loss-of-function PIGC mutations were identified in 4 families to date. PIGC encodes a subunit of the GPI-N-acetylglucosaminyltransferase (GPI-GnT complex). Functional studies on individuals with PIGC mutations show a decrease in GPI-anchored proteins (GPI-Aps) at the cell surface demonstrating a defect in the biosynthesis of GPI-Aps. Approximately one in every 200 mammalian proteins is a GPI-Aps. These proteins are important for neurological development and function, embryogenesis, immune response, and signal transduction.