The most common laboratory findings are the presence of predominantly intravascular microangiopathic hemolytic anemia (peripheral blood smear showing schistocytes—helmet cells), elevated LDH secondary to hemolysis and systemic ischemia, reticulocytosis, presence of nucleated red blood cells on peripheral smear, unconjugated hyperbilirubinemia, low plasma haptoglobin, thrombocytopenia (often severe < 20 × 109/L), negative Coombs test, and normal coagulation tests [2–5]. The gene discussed is HP; the disease is congenital thrombotic thrombocytopenic purpura.