Sign in →

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.


Secondary ID

616498

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.

Method Name

Sequence Capture and Targeted Next-Generation Sequencing (NGS)

Reporting Name

IDH1/IDH2 Mutations Analysis, Tumor

Specimen Type

Varies

Specimen 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

Clinical Information

IDH1 and IDH2 (isocitrate dehydrogenase: IDH) genes encode enzymes involved in cellular glucose metabolism. Mutations in the 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. In central nervous system (CNS) tumors, IDH mutations are a diagnostic molecular biomarker for diffuse gliomas and define two biologically distinct groups: IDH-mutant and IDH-wildtype tumors. IDH mutations are rarely observed in other CNS tumor types and are not seen in CNS reactive non-neoplastic processes. IDH mutations are also a molecular biomarker in non-CNS tumors, including acute myeloid leukemia, cholangiocarcinoma, and cartilaginous tumors. Clinically approved targeted therapies are available for a subset of patients with IDH-mutant acute myeloid leukemia and IDH-mutant cholangiocarcinoma.

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.

Day(s) Performed

Monday through Friday

Report Available

12 to 20 days

Specimen 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 testing

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test 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

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.