Ordering Recommendation

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

Mnemonic
VWF2M SEQ
Methodology

Polymerase Chain Reaction/Sequencing

Performed

Varies

Reported

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
Collect

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

Specimen Preparation

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

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

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

Reference Interval

By report

Interpretive Data

Background Information for von Willebrand Disease, Type 2M (VWF) Sequencing:
Characteristics
: Mucocutaneous bleeding after brushing or flossing teeth, unexplained bruising, prolonged repeated nosebleeds, menorrhagia, and prolonged bleeding following childbirth, trauma or surgery.
Incidence
: Approximately 1 in 100 to 1 in 1000 individuals.
Inheritance:
Autosomal dominant for type 2M.
Penetrance:
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.
Cause
: Pathogenic VWF mutations in exons 28, 30, and 31.
Clinical Sensitivity
: 80 percent for vWD types 2A, 2B, and 2M; unknown for other vWD subtypes.
Methodology:
Bidirectional sequencing of VWF exons 28, 30, 31 and its intron-exon boundaries.
Analytical Sensitivity and Specificity
: 99 percent.
Limitations
: 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 28, 30, and 31 will not be evaluated.

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.

Note
Hotline History
N/A
CPT Codes

81403

Components
Component Test Code* Component Chart Name LOINC
2005491 vWD Type 2M (VWF) Sequencing Specimen
2005492 vWD Type 2M (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.
Aliases
  • VWD type 2M sequencing assay
  • VWF2M Sequencing
von Willebrand Disease, Type 2M (VWF) Sequencing