It has been shown that there is a partial or absolute deficiency in the biosynthesis of the glycophosphatidylinositol (GPI)‐anchored proteins in various cell lineages (lymphoid and myeloid) in PNH patients, caused by mutations in the phosphatidylinositol glycan complementation class A (PIGA) gene on the X‐chromosome [2]. This evidence concerns the gene PIGA and paroxysmal nocturnal hemoglobinuria.