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 characterized by developmental delays, neurological issues, and congenital abnormalities.