Until the last decade, only somatic PIGA mutations had been reported in patients with paroxysmal nocturnal hemoglobinuria (PNH) [13, 14]; germline mutations had not been reported in PIGA or any other of the genes involved in GPI anchor biosynthesis and were suspected to result in embryonic lethality [15, 16]. This evidence concerns the gene PIGA and paroxysmal nocturnal hemoglobinuria.