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HelpTest Code GNPLT Platelet Disorders, Comprehensive Gene Panel, Next-Generation Sequencing, Varies
Ordering Guidance
The test is designed to evaluate a variety of hereditary platelet disorders and to be utilized for genetic confirmation of a phenotypic diagnosis of a hereditary platelet disorder.
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 e.g., 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 Focused Gene Panel or GNBLC / Bleeding Comprehensive Panel.
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
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.
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
Specimen Type: Skin biopsy
Supplies: Fibroblast Biopsy Transport Media (T115)
Container/Tube: Sterile container with any standard cell culture media (eg, minimal essential media, RPMI 1640). The solution should be supplemented with 1% penicillin and streptomycin.
Specimen Volume: 4-mm punch
Specimen Stability Information: Refrigerated (preferred)/Ambient
Additional Information: A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing. An additional 3 to 4 weeks is required to culture fibroblasts before genetic testing can occur.
Specimen Type: Cultured fibroblasts
Container/Tube: T-25 flask
Specimen Volume: 2 Flasks
Collection Instructions: Submit confluent cultured fibroblast cells from a skin biopsy from another laboratory. Cultured cells from a prenatal specimen will not be accepted.
Specimen Stability Information: Ambient (preferred)/Refrigerated (<24 hours)
Additional Information: A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing. An additional 3 to 4 weeks is required to culture fibroblasts before genetic testing can occur.
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.
Secondary ID
619285Useful For
Evaluating hereditary platelet disorders in patients with a personal or family history suggestive of a hereditary platelet disorder
Diagnosing hereditary platelet disorders for patients in whom phenotypic testing is nondiagnostic, but there is a strong clinical suspicion of the hereditary platelet disorder
Confirming a hereditary platelet disorder diagnosis with the identification of a known or suspected disease-causing alteration in one or more of 70 genes associated with a variety of hereditary platelet disorders
Determining the disease-causing alterations within one or more of these 70 genes to delineate the underlying molecular defect in a patient with a laboratory diagnosis of a platelet 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 disorders
Carrier testing for close family members of an individual with a hereditary platelet disorder diagnosis
This test is not intended for prenatal diagnosis.
Genetics Test Information
This test utilizes next-generation sequencing to detect single nucleotide and copy number variants in 70 genes associated with a variety of hereditary platelet disorders: ABCC4, ABCG5, ABCG8, ACTB, ACTN1, ANKRD26, ANO6, AP3B1, AP3D1, ARPC1B, BLOC1S3, BLOC1S5, BLOC1S6, CDC42, CYCS, DIAPH1, DTNBP1, ETV6, FERMT3, FLI1, FLNA, FYB1, GATA1, GATA2, GFI1B, GNE, GP1BA, GP1BB, GP6, GP9, HOXA11, HPS1, HPS3, HPS4, HPS5, HPS6, IKZF5, ITGA2B, ITGB3, KDSR, LYST, MASTL, MECOM, MPIG6B, MPL, MYH9, NBEA, NBEAL2, ORAI1, P2RY1, P2RY12, PLA2G4A, PLAU, PRKACG, PTGS1, RASGRP2, RBM8A, RUNX1, SLFN14, SRC, STIM1, STXBP2, TBXA2R, TBXAS1, THPO, TPM4, TUBB1, VIPAS39, VPS33B, and WAS. See Targeted Genes and Methodology Details for Platelet Disorders Comprehensive Gene Panel and Method Description for additional details.
Identification of a disease-causing variant may assist with diagnosis, prognosis, clinical management, recurrence risk assessment, familial screening, and genetic counseling for a variety of hereditary platelet disorders.
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| CULFB | Fibroblast Culture for Genetic Test | Yes | No |
Testing Algorithm
The clinical workup for detecting inherited platelet disorders should begin with a careful review of the 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 non-diagnostic.
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)
For skin biopsy or cultured fibroblast specimens:
For skin biopsy or cultured fibroblast specimens, fibroblast culture testing will be performed at an additional charge. If viable cells are not obtained, the client will be notified.
Special Instructions
Method Name
Sequence Capture and Targeted Next-Generation Sequencing (NGS) followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing
Reporting Name
Platelet Comprehensive Panel, NGSSpecimen Type
VariesSpecimen Minimum Volume
Blood: 1 mL; Cultured fibroblasts/skin biopsy: 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
Platelets have essential roles in primary hemostasis. Patients with either hereditary or acquired platelet disorders usually have bleeding diathesis, which can potentially be life-threatening and may also have issues with the development and/or functioning of major organs.(2) Inherited platelet disorders can be syndromic (ie, associated with current or future development of other organ system defects) or non-syndromic (ie, isolated to thrombocytopenia with no other organ system defects).
A reliable laboratory diagnosis of a platelet disorder can significantly impact patients' and, potentially, their family members' clinical management and outcome. Identification of an alteration that is known or suspected to cause disease aids in confirmation of the diagnosis and potentially provides prognostic information especially in the syndromic inherited platelet disorders.
This panel evaluates 70 genes associated with a variety of hereditary platelet disorders, including reduced adenosine diphosphate (ADP)-induced platelet aggregation; Baraitser-Winter syndrome 1 with macrothrombocytopenia; Scott syndrome; Hermansky-Pudlak syndrome; platelet abnormalities with eosinophilia and immune-mediated inflammatory disease; Takenouchi-Kosaki syndrome with thrombocytopenia; leukocyte integrin adhesion deficiency type III; Paris-Trousseau-Jacobsen syndrome; GATA2 deficiency; Bernard-Soulier syndrome; platelet-type von Willebrand disease; bleeding diathesis due to glycoprotein VI deficiency; Glanzmann thrombasthenia; Chediak-Higashi syndrome; congenital amegakaryocytic thrombocytopenia; May-Hegglin disorder/anomaly; Sebastian syndrome; MYH9-related disorders; autism with platelet dense granule defect; gray platelet syndrome; autosomal dominant tubular aggregate myopathy-2; ADP receptor defect; deficiency of phospholipase A2 group IV A; Quebec platelet disorder; aspirin-like defect; thrombocytopenia-absent radius syndrome; familial platelet disorder with predisposition to acute myeloid leukemia; Stormorken syndrome; York platelet syndrome; familial hemophagocytic lymphohistiocytosis type 5; thromboxane A2 receptor defect; Ghosal syndrome; ARC (arthrogryposis, renal dysfunction, and cholestasis) syndromes 1 and 2; Wiskott-Aldrich syndrome; a variety of platelet-type bleeding disorders; and hereditary/congenital thrombocytopenias, such as various macrothrombocytopenias. These congenital thrombocytopenias include sitosterolemia with macrothrombocytopenia; macrothrombocytopenia and sensorineural hearing loss; thrombocytopenia and susceptibility to cancer; X-linked thrombocytopenia with dyserythropoiesis; myopathy associated with thrombocytopenia; amegakaryocytic thrombocytopenia with radioulnar synostoses 1 and 2; thrombocytopenia and erythrokeraderma; thrombocytopenia anemia and myelofibrosis; and thrombocytopenia progressing to trilineage bone marrow failure.
The risk for developing bleeding or other phenotypic features associated with these disorders and syndromes varies. Several of the genes on this panel have established bleeding, thrombocytopenia, and other hematologic or nonhematologic disease associations. Several of the genes on this panel also have expert group guidelines.(1,3-5)
It is recommended that genetic testing be offered to all patients suspected of having a heritable platelet disorder since some patients may have normal platelet laboratory testing results.(1,6)
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.
Day(s) Performed
Varies
Report Available
28 to 42 daysSpecimen Retention Time
Whole blood: 2 weeks (if available); Extracted DNA: 3 months; Cultured fibroblasts: 1 monthPerforming 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
88233-Tissue culture, skin, solid tissue biopsy (if appropriate)
88240-Cryopreservation (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| GNPLT | Platelet Comprehensive Panel, NGS | 105334-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 619286 | Test Description | 62364-5 |
| 619287 | Specimen | 31208-2 |
| 619288 | Source | 31208-2 |
| 619289 | Result Summary | 50397-9 |
| 619290 | Result | 82939-0 |
| 619291 | Interpretation | 59465-5 |
| 619292 | Additional Results | 82939-0 |
| 619293 | Resources | 99622-3 |
| 619294 | Additional Information | 48767-8 |
| 619295 | Method | 85069-3 |
| 619296 | Genes Analyzed | 82939-0 |
| 619297 | Disclaimer | 62364-5 |
| 619298 | Released By | 18771-6 |