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HelpTest Code GNPFD Platelet Function Defect Gene Panel, Next-Generation Sequencing, Varies
Ordering Guidance
This test is designed to evaluate a variety of hereditary platelet function defect disorders and to be utilized for genetic confirmation of a phenotypic diagnosis of a platelet function defect disorder. If testing for hereditary platelet disorders using a larger, comprehensive panel is desired, a 70-gene platelet panel is available; order GNPLT / Platelet Disorders, Comprehensive Gene Panel, Next-Generation Sequencing, Varies.
This test is not designed to evaluate for hereditary bleeding disorders. For patients with clinical suspicion of an inherited bleeding disorder, it is important to exclude plasmatic factor deficiencies (eg, von Willebrand disease, hemophilia, or other factor deficiencies) prior to considering an inherited platelet function defect. If bleeding is the indication for testing and testing for hereditary bleeding disorders is desired, bleeding panels are available. See GNBLF / Bleeding Disorders, Focused Gene Panel, Next-Generation Sequencing, Varies or GNBLC / Bleeding Disorders, Comprehensive Gene Panel, Next-Generation Sequencing, Varies.
For assessment of hereditary platelet disorders that have ultrastructural abnormalities, such as gray platelet syndrome, order PTEM / Platelet Transmission Electron Microscopic Study, Whole Blood.
For assessment of hereditary platelet disorders due to quantitative surface glycoprotein deficiencies, order PLAFL / Platelet Glycoprotein Flow Platelet Surface Glycoprotein by Flow Cytometry, Blood.
Customization of this panel and single gene analysis for any gene present on this panel are 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 the genes on this panel. See FMTT / Familial Variant, Targeted Testing, Varies. To obtain more information about this testing option, call 800-533-1710.
Shipping Instructions
Specimen preferred to arrive within 96 hours of collection.
Necessary Information
Platelet Esoteric Testing 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
Specimen Type: Whole blood
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.
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
Forms
1. Platelet Esoteric Testing Patient Information 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
Diagnosing hereditary platelet function defect disorders for patients who have a distinct platelet function defect pattern, such as Bernard-Soulier syndrome, revealed by laboratory phenotypic testing
Confirming a hereditary platelet function defect disorder diagnosis with the identification of a known or suspected disease-causing alteration in one or more of 17 genes associated with a variety of hereditary platelet function defect disorders
Determining the disease-causing alterations within one or more of these 17 genes to delineate the underlying molecular defect in a patient with a laboratory diagnosis of a platelet function defect disorder
Identifying the causative alteration for genetic counseling purposes
Prognosis and risk assessment based on the genotype-phenotype correlations
Providing a prognosis in syndromic hereditary platelet function defect disorders
Carrier testing for close family members of an individual with a hereditary platelet function defect disorder diagnosis
This test is not intended for prenatal diagnosis.
Testing Algorithm
The clinical workup for detecting inherited platelet disorders should begin with a careful review of complete blood cell count and peripheral blood smear results as well as other platelet tests, such as light transmission platelet aggregometry, electrical impedance whole blood aggregometry, platelet function analyzer 100 (PFA-100), platelet transmission electron microscopy (TEM) and platelet flow cytometric analysis. TEM is an essential tool for laboratory diagnosis of various hereditary platelet disorders that have ultrastructural abnormalities, such as gray platelet syndrome. Flow cytometry is the preferred method to assess hereditary platelet disorders due to quantitative surface glycoprotein deficiencies.
Platelet laboratory testing may not be able to identify all inherited platelet disorders. Occasionally, the clinical picture may be consistent with a defect in primary hemostasis, but the results of platelet function tests may be normal or nondiagnostic.
Genetic testing for hereditary platelet disorders is indicated if:
-Platelet tests indicate a deficiency or functional abnormality
-There is a clinical suspicion for a hereditary platelet disorder due to family history or patient’s clinical presentation
-Acquired causes of deficiencies associated with platelet disorders have been excluded
If a platelet disorder is a concern, a set of clinical guidelines from the British Society for Haematology on testing for heritable platelet disorders is freely available.(1)
Special Instructions
Method Name
Sequence Capture and Targeted Next-Generation Sequencing (NGS) followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing
Reporting Name
Platelet Function Defect Panel, NGSSpecimen Type
VariesSpecimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | ||
Reference Values
An interpretive report will be provided.
Interpretation
All detected variants are evaluated according to American College of Medical Genetics and Genomics recommendations.(7) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.
Clinical Reference
1. Gomez K, Anderson J, Baker P, et al: Clinical and laboratory diagnosis of heritable platelet disorders in adults and children: a British Society for Haematology Guideline. Brit J Haematol. 2021 Oct;195(1):46-72
2. Nurden AT, Freson K, Selifsohn U: Inherited platelet disorders. Haemophilia. 2012 July;18(s4):154-160
3. International Society on Thrombosis and Haemostasis: Bleeding Thrombotic and Platelet Disorder TIER1 genes. ISTH; 2018. Updated July 2022. Accessed October 6, 2022. Available at: www.isth.org/page/GinTh_GeneLists
4. Megy K, Downes K, Simeoni I, et al: Curated disease-causing genes for bleeding, thrombotic, and platelet disorders: Communication from the SSC of the ISTH. J Thromb Haemost. 2019 Aug;17(8):1253-1260
5. Bolton-Maggs PHB, Chalmers EA, Collins PW, et al: A review of inherited platelet disorders with guidelines for their management on behalf of the UKHCDO. Brit J Haematol. 2006 Dec;135(5):603-633
6. Watson SP, Lowe GC, Lordkipanidze M, Morgan NV, GAPP consortium: Genotyping and phenotyping of platelet function disorders. J Thromb Haemost. 2013 June;11(Suppl 1):351-63
7. Richards S, Aziz N, Bale S, et al; ACMG Laboratory Quality Assurance Committee: Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med. 2015 May;17(5):405-424
Day(s) Performed
Varies
Report Available
28 to 42 daysPerforming 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
81443
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| GNPFD | Platelet Function Defect Panel, NGS | 105333-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 619356 | Test Description | 62364-5 |
| 619357 | Specimen | 31208-2 |
| 619358 | Source | 31208-2 |
| 619359 | Result Summary | 50397-9 |
| 619360 | Result | 82939-0 |
| 619361 | Interpretation | 59465-5 |
| 619362 | Additional Results | 82939-0 |
| 619363 | Resources | 99622-3 |
| 619364 | Additional Information | 48767-8 |
| 619365 | Method | 85069-3 |
| 619366 | Genes Analyzed | 82939-0 |
| 619367 | Disclaimer | 62364-5 |
| 619368 | Released By | 18771-6 |