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
Within 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, 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.





See Compliance Statement C: www.aruplab.com/CS
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 
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Aliases
  • GP1BA Sequencing
  • Platelet Type Von Willebrand Disease (vWD)
  • Pseudo Von Willebrand Disease (vWD)
  • Von Willebrand Disease (vWD) Platelet Type
  • VWD Platelet Type 4