All patients were affected by autoimmune TTP (detectable anti-ADAMTS13 antibodies at least once in the patient’s history, before inclusion in the study); in all women except patient 11, severe ADAMTS13 deficiency (i.e., <10%) was detected in either acute or remission phase, out of pregnancy. The gene discussed is ADAMTS13; the disease is thrombotic thrombocytopenic purpura.