Thrombotic thrombocytopenic purpura (TTP) is a rare microangiopathy presenting with anemia, thrombocytopenia, and neurological deficits, occurring most often in various autoimmune diseases due to inhibition of ADAMTS13 by autoantibodies, as well as in pregnant women with or without an autoimmune substrate. This evidence concerns the gene ADAMTS13 and Thrombocytopenia.