Despite of the fact that the origin of autoimmunity in autism is unknown, immune related genes on major histocompatibility complex, which have been associated with some autoimmune diseases, may play a central role in the development of autoimmunity in autism (e.g., HLA-DRB1 and C4B null alleles) [7,10,11]. This evidence concerns the gene HLA-DRB1 and Autoimmunity.