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HelpTest ID: IDTRT IDH1, IDH2, and TERT Mutation Analysis, Next-Generation Sequencing, Tumor
Ordering Guidance
Multiple oncology (cancer) gene panels are available. For more information see Hematology, Oncology, and Hereditary Test Selection Guide.
Necessary Information
A pathology report (final or preliminary), at minimum containing the following information, must accompany specimen for testing to be performed:
1. Patient name
2. Block number-must be on all blocks, slides, and paperwork (can be handwritten on the paperwork)
3. Tissue collection date
4. Source of the tissue
Specimen Required
This assay requires at least 20% tumor nuclei.
-Preferred amount of tumor area with sufficient percent tumor nuclei: tissue 216 mm(2)
-Minimum amount of tumor area: tissue 36 mm(2)
-These amounts are cumulative over up to 10 unstained slides and must have adequate percent tumor nuclei.
-Tissue fixation: 10% neutral buffered formalin, not decalcified
-For specimen preparation guidance, see Tissue Requirement for Solid Tumor Next-Generation Sequencing. In this document, the sizes are given as 4 mm x 4 mm x 10 slides as preferred: approximate/equivalent to 144 mm(2) and the minimum as 3 mm x 1 mm x 10 slides: approximate/equivalent to 36 mm(2).
Preferred:
Specimen Type: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block with acceptable amount of tumor tissue.
Acceptable:
Specimen Type: Tissue slide
Slides: 1 Stained and 10 unstained
Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 10 unstained, nonbaked slides with 5-micron thick sections of the tumor tissue.
Note: The total amount of required tumor nuclei can be obtained by scraping up to 10 slides from the same block.
Additional Information: Unused unstained slides will not be returned.
Specimen Type: Cytology slide (direct smears or ThinPrep)
Slides: 1 to 3 Slides
Collection Instructions: Submit 1 to 3 slides stained and coverslipped with a preferred total of 5000 nucleated cells, or a minimum of at least 3000 nucleated cells.
Note: Glass coverslips are preferred; plastic coverslips are acceptable but will result in longer turnaround times.
Additional Information: Cytology slides will not be returned.
Useful For
Identifying specific mutations within the IDH1 and IDH2 genes and the TERT promoter to assist in tumor diagnosis/classification
Additional Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| SLIRV | Slide Review in MG | No, (Bill Only) | Yes |
Testing Algorithm
When this test is ordered, slide review will always be performed at an additional charge.
Special Instructions
Method Name
Sequence Capture Next-Generation Sequencing (NGS)
Reporting Name
IDH1/2 and TERT Mutation AnalysisSpecimen Type
VariesSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Ambient (preferred) | ||
| Refrigerated | |||
Clinical Information
IDH1 and IDH2 (IDH) genes encode enzymes involved in cellular glucose metabolism. Mutations in IDH genes primarily involve codons R132 in IDH1 and R140 and R172 in IDH2, and lead to the neomorphic ability to generate oncometabolite R(-)-2-hydroxyglutarate, which contributes to tumorigenesis.
TERT gene encodes the catalytic subunit of telomerase, an enzyme complex that regulates telomere length. Mutations in the TERT promoter primarily involve the mutational hotspot positions c.-124 (also known as C228) and c.-146 (also known as C250) and increase telomerase activity allowing tumor cells to overcome cellular senescence.
IDH and TERT promoter mutations are essential diagnostic molecular biomarkers for diffuse gliomas, a group of central nervous system (CNS) tumors. Testing for both biomarkers is often diagnostically necessary. This test simultaneously assesses for somatic mutations involving the IDH and TERT promoter genes. IDH and TERT promoter mutations are also molecular biomarkers for a variety of non-CNS tumors but usually do not co-occur and would be best evaluated by stand-alone IDH and TERT promoter tests.
Reference Values
An interpretive report will be provided.
Interpretation
The interpretation of molecular biomarker analysis includes an overview of the results and the associated diagnostic, prognostic, and therapeutic implications.
Clinical Reference
1. Strom SP. Current practices and guidelines for clinical next-generation sequencing oncology testing. Cancer Biol Med. 2016;13(1):3-11. doi:10.28092/j.issn.2095-3941.2016.0004
2. Spurr L, Li M, Alomran N, et al. Systematic pan-cancer analysis of somatic allele frequency. Sci Rep. 2018;8(1):7735. Published 2018 May 16. doi:10.1038/s41598-018-25462-0
3. WHO Classification of Tumours Editorial Board: Central nervous system tumours. 5th ed. World Health Organization; 2021. WHO Classification of Tumours. Vol 6
4. Killela PJ, Reitman ZJ, Jiao Y, et al: TERT promoter mutations occur frequently in gliomas and a subset of tumors derived from cells with low rates of self-renewal. Proc Natl Acad Sci USA. 2013;110(15):6021-6026
5. Koelsche C, Sahm F, Capper D, et al: Distribution of TERT promoter mutations in pediatric and adult tumors of the nervous system. Acta Neuropathol. 2013;126(6):907-915
6. Eckel-Passow JE, Lachance DH, Molinaro AM, et al: Glioma groups based on 1p/19q, IDH, and TERT promoter mutations in tumors. N Engl J Med. 2015;372(26):2499-2508
7. Cancer Genome Atlas Research Network, Brat DJ, Verhaak RGW, et al: Comprehensive, integrative genomic analysis of diffuse lower-grade gliomas. N Engl J Med. 2015;372(26):2481-2498
8. Yan H, Parsons DW, Jin G, et al: IDH1 and IDH2 mutations in gliomas. N Engl J Med. 2009;360(8):765-773
Day(s) Performed
Monday through Friday
Report Available
12 to 20 daysTest 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
88381-Microdissection, manual
0481U
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| IDTRT | IDH1/2 and TERT Mutation Analysis | 105587-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 619650 | Result | 82939-0 |
| 619651 | Interpretation | 69047-9 |
| 619652 | Additional Information | 48767-8 |
| 619653 | Specimen | 31208-2 |
| 619654 | Tissue ID | 80398-1 |
| 619655 | Method | 48767-8 |
| 619656 | Disclaimer | 62364-5 |
| 619657 | Released By | 18771-6 |
Forms
If not ordering electronically, complete, print, and send a Oncology Test Request (T729) with the specimen.
mml-neuro-oncology-oms