Von Willebrand Disease Type 2B: VWF Exon 28 Sequencing

Diagnostic Use

Von Willebrand disease (VWD) arises from a qualitative or quantitative deficiency of Von Willebrand factor (VWF), a multimeric protein that is required for platelet adhesion. Type 2 VWD (20-30% of all VWD cases) is a qualitative defect and the bleeding tendency can vary between individuals. There are normal levels of VWF, but the multimers are structurally abnormal or subgroups of large or small multimers are absent. VWD Type 2B is a "gain of function" autosomal dominant defect leading to spontaneous binding to platelets and subsequent rapid clearance of the platelets and the large VWF multimers. A mild thrombocytopenia may occur. The large VWF multimers are absent in the circulation and the factor VIII binding is normal.


Genetics - Molecular Pathology

Delphic Registration Code


Constituent Tests

Turnaround Time

4 weeks