With respect to the different isotypes of aCL, aCL-IgG and aCL-IgM are generally considered to be more strongly associated with the clinical manifestation of APS than aCL-IgA [15–17] and the detection of aCL-IgM antibodies theoretically reflects an early stage of the disease opposed to aCL-IgG which reflects a sustained class-switched immune response. The gene discussed is CD40LG; the disease is autoimmune polyendocrinopathy.