As a consensus of the International Working Group for Thrombotic Thrombocytopenic Purpura in 2017, thrombotic thrombocytopenic purpura can be distinguished from other causes of thrombotic microangiopathies by the finding of severe ADAMTS13 deficiency to less than 10%7. This evidence concerns the gene ADAMTS13 and thrombotic thrombocytopenic purpura.