von Willebrand Disease, Type 2A (VWF) Sequencing Exon 28 with Reflex to 9 Exons
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.

Statement C: Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

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

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 Code(s)
Component Test Code*Component Chart NameLOINC
2005481vWD Type 2A (VWF) Sequencing Specimen
2005482vWD 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 view this test within the Laboratory Test Directory found at www.aruplab.com
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