Biogenesis of GPI-anchored proteins is a conserved post-translational mechanism in eukaryotes and is important for attaching these proteins to the cell membrane, for protein sorting, trafficking, and dynamics. There are at least 27 genes involved in biosynthesis and remodelling of GPI anchors. PIGN is involved in the eighth step of GPI biosynthesis, so mutations in PIGN cause decreased expression levels of GPI anchored proteins.
The PIGN gene is involved in the eighth step of GPI biosynthesis, so PIGN deficient cells express decreased levels of GPI anchored proteins. GPI anchored proteins play vital roles in numerous biological processes, such as neuronal development. The decreased levels of GPI anchored proteins cause abnormal neuronal development which can lead to intellectual disability, developmental delay, and epilepsy.