Almost all participants offer APS investigations (98.9%; n = 346/350); lupus anticoagulant and anticardiolipin antibodies (ACA) are generally performed by most participants (see Table 2), anti-β2-glycoprotein antibodies testing is performed by less than half of respondents (IgM testing: 36.9%; n = 129/350 and IgG testing: 42.3%; n = 148/350). This evidence concerns the gene CD40LG and autoimmune polyendocrinopathy.