Test Code IDHT IDH1 and IDH2 Mutation Analyses, Next-Generation Sequencing, Tumor
Ordering Guidance
If this test is ordered with TERTD / TERT Promoter Mutation Analysis, Droplet Digital PCR, Tumor, this test will be canceled and IDTRT / IDH1, IDH2, and TERT Mutation Analysis, Next-Generation Sequencing, Tumor will be ordered.
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 Requirements 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 slides
Slides: 1 Stained and 10 unstained
Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 10 unstained, nonbaked slides wit 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 slides (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 that assist in tumor diagnosis/classification and predict response to targeted therapy
Genetics Test Information
This test uses targeted next-generation sequencing to evaluate for somatic mutations within the IDH1 and IDH2 genes. See Targeted Genes and Methodology Details for IDH1/IDH2 Mutation Analysis for details regarding the targeted gene regions evaluated by this test.
This test is performed to evaluate for somatic mutations within solid tumor samples. It does not assess for germline alterations within the genes listed.
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
Reporting Name
IDH1/IDH2 Mutations Analysis, TumorSpecimen Type
VariesSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Ambient (preferred) | ||
Refrigerated |
Reject Due To
Specimens that have been decalcified (all methods) Specimens that have not been formalin-fixed, paraffin-embedded, except for cytology slides Extracted nucleic acid (DNA/RNA) |
Reject |
Reference Values
An interpretive report will be provided.
Supportive Data
Performance Characteristics:
The limit of detection for calling a somatic variant (single nucleotide variants [SNV] and deletions/insertions [delins, formerly indels]) is 5% variant allele frequency and having at least 500x deduplicated coverage.
Verification studies demonstrated concordance between this test and the reference method for detection of SNV and delins is 99.7% (699/701) and 96.6% (226/234) of variants, respectively. Concordance for the detection of delins was 98.9% (186/188) in variants 1 to 10 base pairs (bp) in size, 95.8% (23/24) in variants 11 to 50 bp in size, and 88.9% (8/9) in variants 51 to 200 bp in size.
Day(s) Performed
Monday through Friday
Report Available
12 to 20 daysSpecimen Retention Time
FFPE tissue block: Unused portions of blocks will be returned within 10-14 days after testing is complete; FFPE tissue/cytology slides: Unused tissue slides are stored indefinitely; Digital images are obtained and stored for all slides used in testingPerforming Laboratory
Mayo Clinic Laboratories in RochesterCPT Code Information
88381-Microdissection, manual
81479
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
IDHT | IDH1/IDH2 Mutations Analysis, Tumor | 104323-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
617913 | Result | 82939-0 |
617914 | Interpretation | 69047-9 |
617915 | Additional Information | 48767-8 |
617916 | Specimen | 31208-2 |
617917 | Tissue ID | 80398-1 |
617918 | Method | 85069-3 |
617919 | Disclaimer | 62364-5 |
617920 | Released By | 18771-6 |
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.