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Test Identifier Information


Coding regions of exons and flanking intronic sequences of the GPIBA gene are amplified by PCR and analysed by automated fluorescent bi-directional DNA sequencing.

Diagnostic Use / Indications

Pseudo-von Willebrand disease (Pseudo-VWD) is a rare autosomal dominant bleeding disorder that results from a gain-of-function mutation. Pseudo-VWD, also known as platelet type VWD, results from an abnormally high affinity interaction between the platelet glycoprotein Ib (GPIb) and its adhesive ligand von Willebrand factor (VWF), leading to characteristic platelet hyperaggregability. Rapid clearance of high molecular-weight VWF multimers from plasma, together with thrombocytopenia caused by an increased removal of the aggregated platelets, contribute tot eh bleeding problems experienced by patients with pseudo-VWD including frequent sever nosebleeds and excessive bleeding following surgical operations. The conditions share most of the clinical and laboratory features of type IIB VWD and the final discrimination between these conditions requests either platelet-mixing studies or a molecular genetic analysis.

Constituent TestsGenomic DNA Extraction ;
External Price$0.00(Exclusive of GST)

Specimen Collection

Patient Specimen4.0mL EDTA,
Paediatric Specimen0.5 mL - 1 mL EDTA blood

CHLabs Laboratory

DepartmentBiochemistry - Molecular Pathology
Contact Details Email Email
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Contact Phone Number03 3640 548
Test Availability9am to 5pm, Monday to Friday
Turnaround TimeWithin 4 weeks
Uncertainty of Measurement

 Automated bidirectional DNA sequencing has an analytical sensitivity and specificity of >99%. Note that the lower limit of variant detection of sequencing analysis is ~10%, this is important to consider in the case of mosaicism, mitochondrial, and somatic variation that is not expected to be present at 50% or 100%.  This analysis will not detect variants located within intronic regions, except at the intron-exon boundaries.

Additional Information
  1. This test requires nucleated cells. Please do not centrifuge or freeze blood samples.
  2. Genomic DNA must be extracted from the specimen prior to testing. This incurs an additional charge (see GDNA). Laboratories may prefer to submit DNA for testing. Please provide a minimum of 5 micrograms of DNA at 20 nanograms/microlitre.
  3. If storing blood tube prior to delivery please refrigerate at 4 degrees (transport still at ambient temperature).

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