New missense mutation p.Trp387Ser affecting the functionally important TrpXXTrp motif in the TSR1 repeat of ADAMTS13 metalloproteinase: Case report

Abstract

Upshaw-Schulman syndrome (USS)-rare autosomal recessive disease that affects <1/1 000 000 individuals. It is characterized by the massive formation of platelet thrombi in the microcirculation accompanied by haemolytic anaemia, thrombocytopenia and clinical and laboratory signs of renal and neurological failure. USS is caused by mutations in the ADAMTS13 gene. Mutations in the ADAM metallopeptidase with thrombospondin type 1 motif 13 (ADAMTS13) gene can lead to disruption of secretion of this enzyme, or to decrease of enzyme proteinase activity without effect on ADAMTS13 secretion. The aim of this work is to describe a clinical case of USS caused by a new missense mutation in the ADAMTS13 gene. The diagnosis of thrombotic thrombocytopenic purpura was based on clinical signs and confirmed if plasma ADAMTS13 activity was <10%. ADAMTS13 gene sequencing was performed by the Sanger method using oligonucleotide primers of our own design. We found a new, undescribed mutation p.Trp387Ser in a TrpXXTrp motif. Previously, a pathogenic variation disrupting the 387TrpSerSerTrp390 motif of the ADAMTS13 protein was detected only once. Clinical picture of a patient with the combination of the p. Trp387Ser and p.Arg1060Trp variations is quite similar to that of the homozygous state of p.Arg1060Trp variant.

Hereditary thrombotic thrombocytopenic purpura mimicking idiopathic thrombocytopenic purpura was revealed by miscarriage——Novel Compound Heterozygous Mutations in hTTP

“…Nonsense mutation and frameshift mutation sometimes activate NMD resulting reduced ADAMTS13 [21] . CUB and TSP domains were reported to be in charge of the secretion and conformation changing of ADAMTS13 [18,21,22] . Mutation p.Trp955X terminates the translation of CUB and TSP domains.…”