In the three patients previously reported by Camilleri et al, the heterozygous R1060W mutation was detected, which affects secretion but not activity, although anti-ADAMTS13 antibodies were the root cause of the TTP episode.9Also in our case of pregnancy-onset TTP, the development of anti-ADAMTS13 autoantibodies led to a significant reduction of ADAMTS13 activity allowing precipitation of the disease. The gene discussed is ADAMTS13; the disease is thrombotic thrombocytopenic purpura.