Noncanonical type 2B von Willebrand disease associated with mutations in the VWF D'D3 and D4 domains.

ABSTRACT: We observed a 55-year-old Italian man who presented with mucosal and cutaneous bleeding. Results of his blood analysis showed low levels of von Willebrand factor (VWF) antigen and VWF activity (both VWF ristocetin cofactor and VWF collagen binding), mild thrombocytopenia, increased ristocetin-induced platelet aggregation, and a deficiency of high-molecular-weight multimers, all typical phenotypic hallmarks of type 2B von Willebrand disease (VWD). The analysis of the VWF gene sequence revealed heterozygous in cis mutations: (1) c.2771G>A and (2) c.6532G>T substitutions in the exons 21 and 37, respectively. The first mutation causes the substitution of an Arg residue with a Gln at position 924, in the D'D3 domain. The second mutation causes an Ala to Ser substitution at position 2178 in the

SUBMITTER: Sacco M 

PROVIDER: S-EPMC7391138 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature