Ordering Recommendation

Molecular testing to distinguish von Willebrand disease (VWD) type 2B from pseudo (platelet-type) VWD.




Polymerase Chain Reaction/Sequencing/Fragment Analysis




14-21 days

New York DOH Approval Status

Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.

Specimen Required

Patient Preparation

Lavender (EDTA), pink (K2EDTA) or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature


Unacceptable Conditions

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval

By report

Interpretive Data

Background Information for von Willebrand Disease, Platelet Type (GP1BA) 4 Mutations:
: Mild to moderate mucocutaneous bleeding after brushing or flossing teeth, unexplained bruising, prolonged repeated nosebleeds, menorrhagia, and prolonged bleeding following childbirth, trauma or surgery. Thrombocytopenia may be present and worsen during the stress of severe infection, surgery or pregnancy.
Incidence:  Very rare.
Inheritance: Autosomal dominant. 
Cause: Pathogenic GP1BA mutations.
Clinical Sensitivity: Unknown.
Methodology: Targeted bidirectional sequencing of the GP1BA gene mutations  c.746G>T (p.Gly249Val), c.746G>A (p.Gly249Ser), and c.763A>G (p.Met255Val); PCR followed by fragment analysis of c.1306del27 (p.436_444del9).
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected. GP1BA mutations other than the four targeted, will not be evaluated.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Compliance Category

Laboratory Developed Test (LDT)


Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
2005477 VWD Platelet Type (GP1BA) Seq Spcm
2005478 VWD PlatletType (GP1BA) Seq Interp
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • GP1BA Sequencing
  • Platelet Type Von Willebrand Disease (vWD)
  • Pseudo Von Willebrand Disease (vWD)
  • Von Willebrand Disease (vWD) Platelet Type
  • VWD Platelet Type 4
von Willebrand Disease, Platelet Type (GP1BA) 4 Mutations