In one study, two PNH patients were characterized by an acquired rearrangement of chromosome 12 (der(12) had a break within the 3′ untranslated region of HMGA2 producing an ectopic expression of HMGA2) [20], and in another study, three PNH patients were found harboring a microdeletion of Xp22.2, encompassing the PIGA locus [21]. The gene discussed is PIGA; the disease is paroxysmal nocturnal hemoglobinuria.