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Test Code GNVWD von Willebrand Disease, VWF and GP1BA Genes, Next-Generation Sequencing, Varies


Ordering Guidance


A systematic diagnosis through conventional coagulation testing is recommended before considering genetic testing for any suspected bleeding disorder. Special coagulation testing for evaluating patients suspected of having von Willebrand disease is available; order AVWPR / von Willebrand Disease Profile, Plasma.

 

If testing for hereditary bleeding disorders using a larger panel is desired, both a 6-gene and a 25-gene bleeding panel are available. For more information see GNBLF / Bleeding Disorders, Focused Gene Panel, Next-Generation Sequencing, Varies or GNBLC / Bleeding Disorders, Comprehensive Gene Panel, Next-Generation Sequencing, Varies.

 

Customization of this panel and/or single gene analysis for any gene present on this panel is available. For more information see CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies.

 

Targeted testing for familial variants (also called site-specific or known variants testing) is available for VWF and GP1BA genes. See FMTT / Familial Variant, Targeted Testing, Varies. To obtain more information about this testing option, call 800-533-1710.



Additional Testing Requirements


All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen as this must be a different order number than the prenatal specimen.



Shipping Instructions


Specimen preferred to arrive within 96 hours of collection.



Necessary Information


von Willebrand Disease Patient Information is required. Testing may proceed without the patient information; however, the information aids in providing a more thorough interpretation. Ordering providers are strongly encouraged to fill out the form and send with the specimen.



Specimen Required


Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. For instructions for testing patients who have received a bone marrow transplant, call 800-533-1710.

 

Submit only 1 of the following specimens:

 

Specimen Type: Whole blood

Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: Yellow top (ACD)

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send whole blood specimen in original tube. Do not aliquot.

Specimen Stability Information: Ambient (preferred) 4 days/Refrigerated

 

Prenatal Specimens

Due to its complexity, consultation with the laboratory is required for all prenatal testing; call 800-533-1710 to speak to a genetic counselor. 

 

Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

Specimen Volume: 20 mL

Specimen Stability Information: Refrigerated (preferred)/Ambient

Additional information:

1. A separate culture charge will be assessed under CULAF / Culture for Genetic Testing, Amniotic Fluid.

2. All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.

 

Specimen Type: Chorionic villi

Container/Tube: 15-mL tube containing 15 mL of transport media

Specimen Volume: 20 mg

Specimen Stability Information: Refrigerated

Additional Information:

1. A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing.

2. All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.

 

Acceptable:

Specimen Type: Confluent cultured cells

Container/Tube: T-25 flask

Specimen Volume: 2 Flasks

Collection Instructions: Submit confluent cultured cells from another laboratory.

Specimen Stability Information: Ambient (preferred)/Refrigerated

Additional Information:

All prenatal specimens must be accompanied by a maternal blood specimen; order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.


Forms

1. von Willebrand Disease Patient Information (T825) is required.

2. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing (Spanish) (T826)

3. If not ordering electronically, complete, print, and send an Coagulation Test Request (T753) with the specimen.

Useful For

Evaluating von Willebrand disease and platelet-type von Willebrand disease in patients with a personal or family history suggestive of von Willebrand disease

 

Confirming von Willebrand disease or platelet-type von Willebrand disease diagnoses with the identification of a known or suspected disease-causing alteration in the VWF or GP1BA genes, respectively

 

Determining the disease-causing alterations within the VWF or GP1BA genes to delineate the underlying molecular defect in a patient with a laboratory diagnosis of von Willebrand disease or platelet-type von Willebrand disease, respectively

 

Subtyping von Willebrand disease as type 1 (most common), type 2 variants (less common), or type 3 (rare), as well as distinguishing von Willebrand disease from platelet-type von Willebrand disease

 

Identifying the causative alteration for genetic counseling purposes

 

Prognosis and risk assessment based on the genotype-phenotype correlations

 

Carrier testing for close family members of an individual with a von Willebrand disease or platelet-type von Willebrand disease diagnosis

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
CULFB Fibroblast Culture for Genetic Test Yes No
CULAF Amniotic Fluid Culture/Genetic Test Yes No
MATCC Maternal Cell Contamination, B Yes No

Method Name

Sequence Capture and Targeted Next-Generation Sequencing (NGS) followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing

Reporting Name

VWF and GP1BA Genes, Full Gene NGS

Specimen Type

Varies

Specimen Minimum Volume

Blood: 1 mL; Amniotic fluid: 10 mL; Other specimen types: see Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

von Willebrand disease (VWD) is the most common inherited bleeding disorder, affecting approximately 1% of the population. VWD is a bleeding diathesis that usually involves mucous membranes and skin sites. It is typically of mild to moderate severity, although life-threatening bleeding in the central nervous system or gastrointestinal tract can occur. The most common presenting symptoms in individuals affected by VWD include epistaxis, menorrhagia, bleeding after dental extraction, postoperative bleeding, ecchymoses, bleeding from minor cuts or abrasions, gingival bleeding, and hemarthrosis.(1) While VWD occurs with equal frequency among men and women, symptoms in women are more obvious because of increased bleeding during menstrual periods, pregnancy, and after childbirth.

 

VWD is a result of defects in the concentration, structure, or function of von Willebrand factor (VWF), leading to decreased factor VIII (FVIII) in circulation and/or impaired platelet adhesion and aggregation at the site of vascular injury. The VWF gene encodes for VWF, a protein that protects blood clotting FVIII from degradation in circulation and promotes platelet adhesion and aggregation at the site of vascular injury. In circulation, VWF assembles into linear strings called multimers, the size of which is biologically important; larger multimers being more reactive than smaller multimers.

 

Levels of factor VIII, VWF antigen, and VWF activity may vary greatly within each individual over time and also with blood type (normal type "O" individuals may have VWF lower than normal individuals of other blood groups). VWF levels (and factor VIII) can be elevated in liver disease, pregnancy, estrogen therapy, inflammation, and after exercise (acute-phase reactant). VWF levels in hemophilia are normal.

 

This panel evaluates 2 genes associated with von Willebrand disease and platelet-type von Willebrand disease. Discrimination between these 2 heritable disorders, specifically concerning types 2A and 2B VWD and platelet-type VWD, using genetic analysis can help guide treatment. Genetic testing can also be used to assist in discriminating between type 2N VWD and hemophilia A. Subtyping of VWD using genetic analysis is important for prognosis and in guiding treatment, as well as determining inheritance pattern and risks for family members.(1,2)

 

The risk for developing bleeding associated with these disorders and subtypes varies. The VWF and GP1BA genes have established bleeding risk and expert group guidelines.(1-4)

 

It is recommended that genetic testing be offered to all patients where it may assist in diagnosis and management of von Willebrand disease.(1) Genetic testing is integral to the conclusive diagnosis of platelet-type von Willebrand disease.(5)

Reference Values

An interpretive report will be provided.

Day(s) Performed

Varies

Report Available

28 to 42 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

81408

81479

81479 (if appropriate for government payers)

88233-Tissue culture, skin, solid tissue biopsy (if appropriate)

88240-Cryopreservation (if appropriate)

88235-Amniotic fluid culture (if appropriate)

81265-Maternal cell contamination (if appropriate)