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von Willebrand Disease, Platelet Type (GP1BA) 4 Mutations
2005476
Ordering Recommendation

Molecular testing to distinguish von Willebrand disease (vWD) type 2B from pseudo (platelet-type) vWD.

Mnemonic
GP1BA SEQ
Methodology
Polymerase Chain Reaction/Sequencing/Fragment Analysis
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.
ARUP Consult®
Disease Topics
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, Platelet Type (GP1BA) 4 Mutations:
Characteristics
: Mild to moderate mucocutaneous bleeding after brushing or flossing teeth, unexplained bruising, prolonged repeated nosebleeds, menorrhagia, and prolonged bleeding following childbirth, trauma or surgery. Thrombocytopenia may be present and worsen during the stress of severe infection, surgery or pregnancy.
Incidence: Very rare.
Inheritance: Autosomal dominant.
Cause: Pathogenic GP1BA mutations.
Clinical Sensitivity: Unknown.
Methodology: Targeted bidirectional sequencing of the GP1BA gene mutations c.746G>T (p.Gly249Val), c.746G>A (p.Gly249Ser), and c.763A>G (p.Met255Val); PCR followed by fragment analysis of c.1306del27 (p.436_444del9).
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected. GP1BA mutations other than the four targeted, will not be evaluated.

Compliance Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test. However, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing. Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
CPT Code(s)
81400
Components
Component Test Code*Component Chart NameLOINC
2005477VWD Platelet Type (GP1BA) Seq Spcm
2005478VWD PlatletType (GP1BA) Seq 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
  • GP1BA Sequencing
  • Platelet Type Von Willebrand Disease (vWD)
  • Pseudo Von Willebrand Disease (vWD)
  • Von Willebrand Disease (vWD) Platelet Type
  • VWD Platelet Type 4