Recessive mutations in ADAMTS13 are responsible for a condition called thrombotic thrombocytopenic purpura (TTP), which is caused by a failure to cleave the otherwise pro-thrombogenic ultra-large von Willebrand Factor multimers in the circulation, resulting in platelet aggregation and vessel occlusion [54]. This evidence concerns the gene VWF and thrombotic thrombocytopenic purpura.