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HelpTest Code TERTD TERT Promoter Mutation Analysis, Droplet Digital PCR, Tumor
Ordering Guidance
For the preferred test to assess for somatic hotspot mutations in the TERT, IDH1, and IDH2 genes, order IDTRT / IDH1, IDH2 and TERT Mutation Analysis, Next-Generation Sequencing, Tumor.
If this test is ordered with IDHT / IDH1 and IDH2 Mutations Analyses, Next-Generation Sequencing, Tumor, this test will be canceled and ordered as IDTRT.
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 5% nuclei of tumor cells/cells of interest.
-Preferred amount of tumor area with sufficient percent tumor nuclei: tissue144 mm(2)
-These amounts are cumulative over up to 10 unstained slides and must have adequate percent nuclei of tumor cells/cells of interest.
-Tissue fixation: 10% neutral buffered formalin, not decalcified
-Cytology fixatives: Cytology smears fixed in alcohol and thin preps fixed with CytoLyt.
Preferred: Submit 3, if available, or 2 of the following specimens.
Acceptable: Submit at least one of the following specimens.
Specimen Type: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block with acceptable amount of tumor tissue.
Specimen Type: Tissue slide
Slides: 1 Hematoxylin and eosin-stained and 10 unstained
Collection Instructions:
Submit the followings slides:
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 total of 5000 nucleated cells (preferred) or at least 3000 nucleated cells (minimum).
Note: Glass coverslips are preferred; plastic coverslips are acceptable but will result in longer turnaround times.
Additional Information: Cytology slides will not be returned. An image of the slides will be stored per regulatory requirements.
Useful For
Identifying specific mutations within the TERT promoter that assist in tumor diagnosis/classification
Genetics Test Information
This test uses droplet digital PCR (ddPCR) to evaluate for the presence of the c.-124C>T (also known as C228T) and c.-146C>T (also known as C250T) somatic mutations in the promoter region of the TERT gene. TERT promoter analysis ddPCR is a highly sensitive testing platform that can detect the c.-124C>T (C228T) and c.-146C>T (C250T) hotspot mutations at low levels, which may be observed in specimens with low number or proportion (%) of tumor cells/cells of interest.
This test cannot differentiate between somatic mutations and germline variant origin and is not intended to assess for germline risk.
Additional Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| SLIRV | Slide Review in MG | No | Yes |
Testing Algorithm
When this test is ordered, slide review will always be performed at an additional charge.
Reporting Name
TERT Promoter Analysis ddPCR, TumorSpecimen Type
VariesSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Ambient (preferred) | |
| Refrigerated | ||
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
An interpretive report will be provided.
Supportive Data
The TERT C228T and C250T droplet digital polymerase chain reaction (ddPCR) assays were shown to be reproducible, with 100% concordance for intra/inter-assay reproducibility experiments. Concordance between results by ddPCR and next-generation sequencing (NGS) for formalin-fixed paraffin-embedded samples was 98% (52/53), with the single discordant result (positive by ddPCR and negative for NGS) explained by the increased sensitivity of ddPCR relative to NGS technology. The analytical sensitivity of these assays was shown to be 1% fraction abundance of mutant copies at 2.5 ng DNA input (equivalent to at least 495 wild-type copies). All expected negative samples tested negative, and there was no cross reactivity between TERT C228T and C250T assays.
Day(s) Performed
Monday through Friday
Report Available
6 to 12 daysSpecimen Retention Time
Tissue blocks: Unused portions of blocks will be returned; Tissue slides: Unused slides are stored for at least 5 years; Extracted DNA: 3 monthsFFPEPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
81345
88381-Microdissection, manual
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TERTD | TERT Promoter Analysis ddPCR, Tumor | 95778-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 618698 | Result Summary | 50397-9 |
| 618699 | Result | 82939-0 |
| 618700 | Interpretation | 69047-9 |
| 618701 | Additional Information | 48767-8 |
| 618704 | Specimen | 31208-2 |
| 618705 | Source | 31208-2 |
| 618706 | Tissue ID | 80398-1 |
| 618702 | Method | 85069-3 |
| 618703 | Disclaimer | 62364-5 |
| 618707 | Released By | 18771-6 |
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.