Enrolled patients most frequently had de novo prolonged or progressive thrombocytopenia defined as platelet count < 50,000/mm3 or 50% reduction from baseline level (6/14, 43%), followed by decreased hemoglobin concentration (4/14, 29%), decreased serum haptoglobin (3/14, 21%), and sudden and persistent increase in LDH (2/14, 14%). This evidence concerns the gene HP and Thrombocytopenia.