Ordering Recommendation

Molecular testing to confirm a phenotypic diagnosis of von Willebrand disease type 2A.




Polymerase Chain Reaction/Sequencing




21-28 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, Type 2A (VWF) Sequencing Exon 28 with Reflex to 9 Exons.
: Mucocutaneous bleeding after brushing or flossing teeth, unexplained bruising, prolonged repeated nosebleeds, menorrhagia, and prolonged bleeding following childbirth, trauma or surgery.
: Approximately 1 in 100 to 1 in 1000 individuals.
Autosomal dominant for types 2B, 2M and most of 2A; autosomal recessive for 20 percent of 2A.
Dominant mutations are incompletely penetrant when VWF: Ag and VWF: RCo levels are 25-50 IU/dL.  Full penetrance is expected when VWF: Ag and VWF: RCo levels are less than 25 IU/dL.
: Pathogenic VWF mutations.
Clinical Sensitivity
: 99 percent for vWD type 2A and 80 percent for types 2B and 2M; unknown for other vWD subtypes.
Bidirectional sequencing of VWF exon 28 and its intron-exon boundaries; if no pathogenic mutations are detected, bidirectional sequencing of exons 11, 12, 14, 15, 16, 24, 25, 51, and 52 and the corresponding intron-exon boundaries is performed.
Analytical Sensitivity and Specificity
: 99 percent.
Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletion/duplications will not be detected. Mutations lying outside of VWF exons 11, 12, 14, 15, 16, 24, 25, 28, 51 and 52 are not 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)


Exon 28 sequencing is performed on all samples. If results do not explain the clinical scenario, then sequencing of 9 exons (11, 12, 14, 15, 16, 24, 25, 51 and 52) will be added. Additional charges apply.

Hotline History


CPT Codes

81403; If reflexed, add 81405


Component Test Code* Component Chart Name LOINC
2005481 vWD Type 2A (VWF) Sequencing Specimen
2005482 vWD Type 2A (VWF) Sequencing 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.


  • VWD platelet type 2A reflex
  • VWF2A Sequencing
von Willebrand Disease, Type 2A (VWF) Sequencing Exon 28 with Reflex to 9 Exons (Temporary Referral as of 02/10/21)