The goal of the study is to gather as much information as precisely as possible concerning the course of illness, factors that may trigger episodes (i.e. pregnancy, infections, etc.), plasma therapy and other treatments from as many patients with Upshaw-Schulman Syndrome as possible. During a second step, the information gathered is to be used in development recommendations on therapies. Since it seems possible that the clinical course is influenced by genetic factors (e.g. the ADAMTS13 mutations, Von Willebrand factor-mirror, etc., as the case may be), familial factors, or event transient and environmental factors (taking medications, pregnancy, etc.), these factors will be investigated using a questionnaire, laboratory studies, and studies on family members.

The long-term goal of the study is to build a network, including a knowledge platform, to exchange experiences on therapy, on the occurrence of side-effects during treatment, and on long-term progress, thereby improving treatment and prevention for affected patients. Treating physicians and affected patients will have access to the knowledge platform.