Thromboxane A2 Receptor Deficiency via the TBXA2R 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 | |
|---|---|---|---|---|---|
| 8929 | TBXA2R | 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
Thromboxane A2 Receptor (TXA2R) deficiency is a rare bleeding disorder that has been reported in fewer than 50 individuals to date. Symptoms include mild to moderate bleeding primarily at mucosal surfaces, easy bruising and epistaxis (Mumford et al. 2010). TXA2R deficiency onset typically occurs during childhood with symptoms being corollary to the degree of TXA2R impairment (Hirata et al. 1994). Genetic testing is helpful for distinguishing TXA2R deficiency from other platelet related bleeding disorders.
Genetics
TXA2R deficiency is inherited in an autosomal dominant manner through pathogenic variants in the TBXA2R gene. Autosomal recessive cases have been reported with individuals having more severe bleeding (Hirata et al. 1994). Missense variants have been reported in all but one case with that individual having a small insertion leading to a frameshift (Mumford et al. 2013; Mumford et al. 2010; Hirata et al. 1994; Kamae et al. 2011). Missense variants have been shown to disrupt thromboxane A2 receptor function through a variety of mechanisms including impaired ligand binding, decreased surface expression, and impaired G-protein coupled receptor signal transduction (Gleim et al. 2013). The TBXA2R gene encodes the thromboxane A2 receptor present on platelets, vascular endothelium, monocytes, and smooth muscle cells. In platelets, thromboxane A2 binds the receptor to mediate platelet aggregation and promote clotting (Wu et al. 1981).
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 TBXA2R pathogenic variants reported to date are detectable by sequencing.
Testing Strategy
This test provides full coverage of all coding exons of the TBXA2R 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
Candidates for testing have normal coagulation, impaired platelet aggregation with mild bleeding. Laboratory findings include delayed platelet aggregation in response to arachidonic acid (Mumford et al. 2013).
Candidates for testing have normal coagulation, impaired platelet aggregation with mild bleeding. Laboratory findings include delayed platelet aggregation in response to arachidonic acid (Mumford et al. 2013).
Gene
| Official Gene Symbol | OMIM ID |
|---|---|
| TBXA2R | 188070 |
| Inheritance | Abbreviation |
|---|---|
| Autosomal Dominant | AD |
| Autosomal Recessive | AR |
| X-Linked | XL |
| Mitochondrial | MT |
Disease
| Name | Inheritance | OMIM ID |
|---|---|---|
| Bleeding Disorder, Platelet-Type, 13, Susceptibility To | AD | 614009 |
Citations
- Gleim S, Stitham J, Tang WH, Li H, Douville K, Chelikani P, J.Rade J, Martin KA, Hwa J. 2013. Human Thromboxane A2 Receptor Genetic Variants: In Silico, In Vitro and “In Platelet” Analysis. PLoS ONE 8: e67314. PubMed ID: 23840660
- Hirata T, Kakizuka A, Ushikubi F, Fuse I, Okuma M, Narumiya S. 1994. Arg60 to Leu mutation of the human thromboxane A2 receptor in a dominantly inherited bleeding disorder. Journal of Clinical Investigation 94: 1662. PubMed ID: 7929844
- Kamae T, Kiyomizu K, Nakazawa T, Tadokoro S, Kashiwagi H, Honda S, Kanakura Y, Tomiyama Y. 2011. Bleeding tendency and impaired platelet function in a patient carrying a heterozygous mutation in the thromboxane A2 receptor: Platelet function and TXA2R mutation. Journal of Thrombosis and Haemostasis 9: 1040–1048. PubMed ID: 21342433
- Mumford AD, Dawood BB, Daly ME, Murden SL, Williams MD, Protty MB, Spalton JC, Wheatley M, Mundell SJ, Watson SP. 2010. A novel thromboxane A2 receptor D304N variant that abrogates ligand binding in a patient with a bleeding diathesis. Blood 115: 363–369. PubMed ID: 19828703
- Mumford et al. 2013. PubMed ID: 23279270
- Wu KK, Breton GC Le, Tai H-H, Chen YC. 1981. Abnormal platelet response to thromboxane A2. Journal of Clinical Investigation 67: 1801. PubMed ID: 6263954
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
Loading...
×
ORDER OPTIONS
View Ordering Instructions1) Select Test Type
2) Select Additional Test Options
No Additional Test Options are available for this test.