Based on the patient’s clinical history and on the physical examination, cardiac structural abnormalities and PNH were ruled out, while IgG and IgM cardiolipin antibody titers and IgG and an IgM β2-glycoprotein-I antibody titer in the negative range of values (Table 1) confirmed the absence of antiphospholipid syndrome. The gene discussed is CD40LG; the disease is paroxysmal nocturnal hemoglobinuria.