This study is a survey in Japan of recombinant ADAMTS13 used to treat or to prevent participants with congenital thrombotic thrombocytopenic purpura (cTTP). The study sponsor will not be involved in how the participants are treated but will provide instructions on how the clinics will record what happens during the study.

The main aim of the study is to check for side effects related from recombinant ADAMTS13 and to check if recombinant ADAMTS13 improves or prevents cTTP.

During the study, participants with cTTP will take recombinant ADAMTS13 intravenous injection according to their clinic's standard practice. The study doctors will check for side effects from recombinant ADAMTS13 for 18 months.

Inclusion Criteria:

- All participants with congenital thrombotic thrombocytopenic purpura (cTTP), treated with recombinant ADAMTS13

Exclusion Criteria:

- None

The population of this survey are all participants who meet the inclusion/exclusion criteria.

Takeda provides access to the de-identified individual participant data (IPD) for eligible studies to aid qualified researchers in addressing legitimate scientific objectives (Takeda's data sharing commitment is available on https://clinicaltrials.takeda.com/takedas-commitment?commitment=5). These IPDs will be provided in a secure research environment following approval of a data sharing request, and under the terms of a data sharing agreement.

IPD from eligible studies will be shared with qualified researchers according to the criteria and process described on https://vivli.org/ourmember/takeda/. For approved requests, the researchers will be provided access to anonymized data (to respect patient privacy in line with applicable laws and regulations) and with information necessary to address the research objectives under the terms of a data sharing agreement.