Familial Platelet Function Disorder via the GP6 Gene
Summary and Pricing 
Test Method
Exome Sequencing with CNV Detection
| Test Code | Test Copy Genes | Test CPT Code | Gene CPT Codes Copy CPT Code | Base Price | |
|---|---|---|---|---|---|
| 4163 | GP6 | 81479 | 81479,81479 | $990 | Order Options and Pricing |
Pricing Comments
Our favored testing approach is exome based NextGen sequencing with CNV analysis. This will allow cost effective reflexing to PGxome or other exome based tests. However, if full gene Sanger sequencing is desired for STAT turnaround time, insurance, or other reasons, please see link below for Test Code, pricing, and turnaround time information. If the Sanger option is selected, CNV detection may be ordered through Test #600.
An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.
Click here for costs to reflex to whole PGxome (if original test is on PGxome Sequencing platform).
Click here for costs to reflex to whole PGnome (if original test is on PGnome Sequencing platform).
The Sanger Sequencing method for this test is NY State approved.
For Sanger Sequencing click here.Turnaround Time
3 weeks on average for standard orders or 2 weeks on average for STAT orders.
Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.
Targeted Testing
For ordering sequencing of targeted known variants, go to our Targeted Variants page.
Clinical Features and Genetics
Clinical Features
Defects in GPVI protein function are associated with prolonged bleeding due to impairment of platelet adhesion to collagen. This disorder often involves mild bleeding defects with individuals being asymptomatic until incursion of trauma or surgical procedures. In rare cases, severe or life-threatening bleeding episodes may require multiple transfusions and/or hospitalization. With the majority of patients being asymptomatic, it is likely an underdiagnosed and under reported disorder (Arthur et al. 2007). Platelet counts may be normal in affected individuals. Primary indications for this disorder are diagnosed by abnormal platelet aggregation in response to collagen or other GPVI agonists such as convulxin (Polgár et al. 1997; Andrews et al. 2001).
Genetics
Familial platelet function disorder via mutations in the GP6 gene is inherited in autosomal recessive manner. To date, missense mutations altering the collagen binding site and small insertions/deletions leading to frameshift and premature protein termination have been reported as causative variants for the disorder (Dumont et al. 2009; Matus et al. 2013; Hermans et al. 2009). GP6 encodes a platelet collagen receptor and is co-associated with another platelet receptor GPIb-IX-V (Jung et al. 2012). In response to collagen binding to GPVI, this adhesion/signaling complex initiates platelet aggregation and initiates secretion of secondary coagulation agonists such as ADP and thromboxane A2 (Arthur et al. 2007).
Clinical Sensitivity - Sequencing with CNV PGxome
Clinical sensitivity cannot be estimated because only a small number of patients have been reported. Analytical sensitivity should be high because all mutations reported are detected by this method.
Testing Strategy
This test provides full coverage of all coding exons of the GP6 gene plus 10 bases of flanking noncoding DNA in all available transcripts along with other non-coding regions in which pathogenic variants have been identified at PreventionGenetics or reported elsewhere. We define full coverage as >20X NGS reads or Sanger sequencing. PGnome panels typically provide slightly increased coverage over the PGxome equivalent. PGnome sequencing panels have the added benefit of additional analysis and reporting of deep intronic regions (where applicable).
Dependent on the sequencing backbone selected for this testing, discounted reflex testing to any other similar backbone-based test is available (i.e., PGxome panel to whole PGxome; PGnome panel to whole PGnome).
Indications for Test
Patients with abnormal platelet aggregation in the presence of collagen or flow cytometry analysis showing decreased GPVI levels are ideal candidates. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in GP6.
Patients with abnormal platelet aggregation in the presence of collagen or flow cytometry analysis showing decreased GPVI levels are ideal candidates. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in GP6.
Gene
| Official Gene Symbol | OMIM ID |
|---|---|
| GP6 | 605546 |
| Inheritance | Abbreviation |
|---|---|
| Autosomal Dominant | AD |
| Autosomal Recessive | AR |
| X-Linked | XL |
| Mitochondrial | MT |
Disease
| Name | Inheritance | OMIM ID |
|---|---|---|
| Bleeding Disorder, Platelet-Type, 11 | AR | 614201 |
Citations
- Andrews RK, Gardiner EE, Shen Y, Berndt MC. 2003. Structure-activity relationships of snake toxins targeting platelet receptors, glycoprotein Ib-IX-V and glycoprotein VI. Curr Med Chem Cardiovasc Hematol Agents 1: 143–149. PubMed ID: 15320694
- Arthur JF, Dunkley S, Andrews RK. 2007. Platelet glycoprotein VI-related clinical defects. Br. J. Haematol. 139: 363–372. PubMed ID: 17910626
- Dumont B, Lasne D, Rothschild C, Bouabdelli M, Ollivier V, Oudin C, Ajzenberg N, Grandchamp B, Jandrot-Perrus M. 2009. Absence of collagen-induced platelet activation caused by compound heterozygous GPVI mutations. Blood 114: 1900–1903. PubMed ID: 19549989
- Hermans C, Wittevrongel C, Thys C, Smethurst PA, Geet C Van, Freson K. 2009. A compound heterozygous mutation in glycoprotein VI in a patient with a bleeding disorder. J. Thromb. Haemost. 7: 1356–1363. PubMed ID: 19552682
- Jung SM, Moroi M, Soejima K, Nakagaki T, Miura Y, Berndt MC, Gardiner EE, Howes J-M, Pugh N, Bihan D, Watson SP, Farndale RW. 2012. Constitutive dimerization of glycoprotein VI (GPVI) in resting platelets is essential for binding to collagen and activation in flowing blood. J. Biol. Chem. 287: 30000–30013. PubMed ID: 22773837
- Matus V, Valenzuela G, Sáez CG, Hidalgo P, Lagos M, Aranda E, Panes O, Pereira J, Pillois X, Nurden AT, Mezzano D. 2013. An adenine insertion in exon 6 of human GP6 generates a truncated protein associated with a bleeding disorder in four Chilean families. J. Thromb. Haemost. 11: 1751–1759. PubMed ID: 23815599
- Polgár J, Clemetson JM, Kehrel BE, Wiedemann M, Magnenat EM, Wells TN, Clemetson KJ. 1997. Platelet activation and signal transduction by convulxin, a C-type lectin from Crotalus durissus terrificus (tropical rattlesnake) venom via the p62/GPVI collagen receptor. J. Biol. Chem. 272: 13576–13583. PubMed ID: 9153205
Ordering/Specimens
Ordering Options
We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.
myPrevent - Online Ordering
- The test can be added to your online orders in the Summary and Pricing section.
- Once the test has been added log in to myPrevent to fill out an online requisition form.
- PGnome sequencing panels can be ordered via the myPrevent portal only at this time.
Requisition Form
- A completed requisition form must accompany all specimens.
- Billing information along with specimen and shipping instructions are within the requisition form.
- All testing must be ordered by a qualified healthcare provider.
For Requisition Forms, visit our Forms page
If ordering a Duo or Trio test, the proband and all comparator samples are required to initiate testing. If we do not receive all required samples for the test ordered within 21 days, we will convert the order to the most effective testing strategy with the samples available. Prior authorization and/or billing in place may be impacted by a change in test code.
Specimen Types
Specimen Requirements and Shipping Details
PGxome (Exome) Sequencing Panel
PGnome (Genome) Sequencing Panel
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ORDER OPTIONS
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2) Select Additional Test Options
No Additional Test Options are available for this test.