von Willebrand Disease, Type 2N (VWF) Sequencing
2005494
 
Ordering Recommendation
Molecular testing to distinguish von Willebrand disease type 2N from hemophilia A.
Mnemonic
VWF2N SEQ
Methodology
Polymerase Chain Reaction/Sequencing
Performed
Varies
Reported
Within 21 days
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory.
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 2N (VWF) Sequencing:
Characteristics
: Mucocutaneous bleeding after brushing or flossing teeth, unexplained bruising, prolonged repeated nosebleeds, menorrhagia, and prolonged bleeding following childbirth, trauma or surgery. Symptoms of type 2N are similar to mild hemophilia A.
Incidence
: Approximately 1 in 100 to 1 in 1000 individuals.
Inheritance:
Autosomal recessive.
Cause:
Pathogenic VWF mutations.
Clinical Sensitivity
: Unknown for VWD type 2N.
Methodology:
Bidirectional sequencing of VWF exons 4, 9, 17, 18, 19, 20, 21, 24, 25, and 27 and the corresponding 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 4, 9, 17, 18, 19, 20, 21, 24, 25, and 27 will not be evaluated.



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS
Note
CPT Code(s)
81405
Components
Component Test Code*Component Chart Name
2005495VWD Type 2N (VWF) Sequencing Specimen
2005496VWD Type 2N (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, contact interface support at interface.support@aruplab.com.
Cross References
  • VWF2N Sequencing