Genotype and Phenotype Correlation in Hereditary Thrombotic Thrombocytopenic Purpura (Upshaw-Schulman Syndrome)
Trial Parameters
Brief Summary
Hereditary thrombotic thrombocytopenic purpura (Upshaw-Schulman syndrome) is a rare disorder characterized by thrombocytopenia as a result of platelet consumption, microangiopathic hemolytic anemia, occlusion of the microvasculature with von Willebrand factor-platelet-thrombic and ischemic end organ damage. The underlying patho-mechanism is a severe congenital ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, 13) deficiency which is the result of compound heterozygous or homozygous ADAMTS13 gene mutations. Although considered a monogenic disorder the clinical presentation in Upshaw-Schulman syndrome patients varies considerably without an apparent genotype-phenotype correlation. In 2006 we have initiated a registry for patients with Upshaw-Schulman syndrome and their family members to identify possible triggers of acute bouts of TTP, to document individual clinical courses and treatment requirements as well as possible side effects of long standing plasma substitution, e.g. alloantibody formation or viral infections.
Eligibility Criteria
Inclusion Criteria: * Severe ADAMTS13 deficiency ( ≤ 10% activity) and no ADAMTS 13 inhibitor on two or more occasions at least one month apart * Being a family member of a confirmed or suspected patient * Molecular analysis of ADAMTS13 gene with one or more mutations and/or positive infusion trial (full recovered ADAMTS13 activity after infused fresh frozen plasma (FFP) with a plasma half-life of 2-4 days)