PIGN (Phosphatidylinositol Glycan Anchor Biosynthesis Class N) is a gene involved in the production of glycosylphosphatidylinositol (GPI) anchors, which attach specific proteins to the cell membrane. These GPI-anchored proteins are essential for processes such as cell adhesion, signal transmission, and immune system function. Mutations in PIGN can disrupt GPI anchor formation, leading to disorders marked by developmental delays, neurological problems, and congenital abnormalities.