A novel homozygous missense ADAMTS13 mutation Y658C in a patient with recurrent thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is a devastating systemic disorder that is characterized by microangiopathic hemolytic anemia, thrombocytopenia, neurological dysfunction, and renal failure. In the hereditary form of TTP, severe deficiency of ADAMTS13, a plasma metalloprotease that cleaves von Willebrand factor, is associated with the development of this disorder. A 34-year-old woman was diagnosed with TTP due to severely reduced ADAMTS13 activity; clinical manifestations resolved only by repeated total plasma exchanges or transfusion. Homozygous and heterozygous Y658C (c.1973A>G) alleles were detected in the patient and her child with severe and mild ADAMTS13 deficiencies, respectively. Herein, we report a novel missense mutation Y658C (c.1973A>G) on exon 17 of ADAMTS13 and discuss its clinical implications.