INTRODUCTIONHereditary thrombotic thrombocytopenic purpura (TTP) is a rare autosomal recessive inherited disease involving the ADMATS13 gene. Common causes of TTP include infection, inflammation or pregnancy. However, hereditary TTP occurs mostly in children and pregnant women, accounting for only 5% of all total cases of TTP.1Homozygous or double heterozygous mutations of theADAMTS13 gene, result in plasma ADAMTS13 activity absence or severe deficiency. ADAMTS13 is located on chromatin 9q34, contains 29 exons, and encodes a 1427 amino acid multidomain protein.2 The most common types of types of mutations are nonsense , followed by missense, frameshift insertions, or deletions, which can be distributed throughout the gene.3Reduced or absent ADAMTS13 activity in the plasma results in the failure of timely degradation of abnormally released von Willebrand factor (VWF) multimers, which can spontaneously bind to platelets, leading to microvascular thrombosis and subsequent organ dysfunction.4,5 Most Hereditary TTP cases are diagnosed during childhood or early adolescence after the first acute episode. Here, we present a case of hereditary TTP in a 30 year old female, which resulted from a compound heterozygous mutation of ADAMTS13 c.1045C > T (p.Arg349Cys) and c.2411G > A(p.Cys 804Tyr).