PIGA, or phosphatidylinositol glycan anchor biosynthesis class A, is a gene that plays a crucial role in the formation of glycosylphosphatidylinositol (GPI) anchors. These anchors are important for attaching proteins to cell membranes, which is essential for various cellular functions, including signaling and adhesion. Mutations in the PIGA gene can lead to a rare genetic disorder known as paroxysmal nocturnal hemoglobinuria (PNH). PNH affects red blood cells, making them more susceptible to destruction, which can result in symptoms like fatigue, abdominal pain, and dark-colored urine. Understanding PIGA is vital for diagnosing and treating related conditions.