ADAMTS13 mutational analysis in Chinese patients with chronic relapsing thrombotic thrombocytopenic purpura

Abstract

Mutational analysis of ADAMTS13 gene was performed on three Chinese children with chronic relapsing thrombotic thrombocytopenic purpura, who all showed severe deficiency (<5% activity) of von Willebrand factor-cleaving protease (vWF-CP) and lack of inhibitors. In two patients, three new mutations, namely G194V, R349C and G1181R, were identified along with a fourth mutation A596V recently described in a French patient. No significant ADAMTS13 gene defect was detected in one patient, in whom the presence of low titer or non-neutralizing antibodies to vWF-CP was not excluded. The prevalence of G194V and G1181R mutations was 1.5% and 5.8% among normal Chinese subjects. They may constitute genetic susceptibility factors for thrombosis in the population.