Criteria to confirm the diagnosis of APS include at least one clinical sign, such as vascular thrombosis or pregnancy complications, and one biochemical criterion such as anticardiolipin IgG or IgM antibodies, lupus anticoagulant of IgG or IgM classes detected in two occasions at least 6–12 weeks a part [7,20]. The gene discussed is CD40LG; the disease is autoimmune polyendocrinopathy.