Test Overview
Test Methodology

Polymerase Chain Reaction (PCR) followed by DNA sequence analysis

Test Usage

IDH1 and IDH2 gene mutations occur in a subset of acute myeloid leukemias and in the majority (70-90%) of both WHO grade II-III astroctyomas and oligodendrogliomas and grade IV secondary glioblastomas. In acute myeloid leukemia, IDH mutation may be an adverse prognostic factor in some subclasses of otherwise molecularly favorable-risk disease. The identification of an IDH mutation in a brain biopsy may be diagnostically helpful in distinguishing glioma from reactive gliosis which lacks IDH mutation. In addition, IDH-mutant gliomas have been associated with a better prognosis than gliomas that lack IDH mutations. This test detects all mutations at codon 132 of IDH1 and codons 140 and 172 of IDH2 in blood, bone marrow, and formalin-fixed paraffin-embedded tissue. Blood and bone marrow specimens should contain at least 30% neoplastic cells to enable mutation detection.

Reference Range *

Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

A negative result does not rule out the presence of a rare IDH mutation outside of the sequenced regions or a low level mutation below the sensitivity of detection (15% mutant allele). Specimens should contain an adequate proportion of neoplastic cells (>30%) to enable mutation detection.

Test Details
Analytic Time

3 - 10 days

Soft Order Code
IDH
MiChart Code
IDH1 and IDH2 Mutations
Synonyms
  • MLABEL
  • IDH1/2 Mutation Detection
  • IDH
  • IDH1 and IDH2 MUTATION DETECTI
Laboratory
Molecular Diagnostics
Section
Molecular Diagnostics
Specimen Requirements
Collection Instructions

Collect blood or bone marrow in a lavender top tube. Refrigerate and send intact blood or bone marrow specimen within 48 hours of collection. Fresh tissue (preferably 0.5cm3, sent in RPMI) and fresh aspirates or body fluids are acceptable. Refrigerate and send, preferably within 24 hours. Frozen tissue specimens – preferably frozen with 1 hour of collection – may also be sent frozen on dry ice. Fresh cell suspensions in RPMI should be refrigerated and sent, preferably within 48 hours. Frozen cell suspensions – preferably frozen with 1 hour of collection – may also be sent frozen on dry ice. Fixed cytogenetic cell suspensions or pellets in Carnoy’s fixative. Refrigerate and send. For formalin-fixed, paraffin-embedded tissue, a block containing an area with a high percentage of neoplastic cells (for micro-/macro-dissection) is preferred. Unstained, UNBAKED slides (5-8, 10-micron slides; 10-15 if few neoplastic cells are present) with associated H&E stained slide are also acceptable. Decalcified tissue or other fixatives will be accepted and the assay attempted, however these may result in failed testing due to degraded nucleic acid. Both blocks and slides should be stored at room temperature.

Alternate Specimen
The preferred specimen is whole blood or bone marrow collected in EDTA (lavender top). However, ACD (yellow top) and heparin (green top) may also be accepted. Previously extracted DNA may also be accepted.
Lavender Top Tube
Normal Volume
5 mL EDTA (lavender) whole blood; 3 mL EDTA (lavender) bone marrow; Fresh/frozen tissue and fresh aspirates or body fluids; Fresh/frozen tissue and fresh aspirates or body fluids; Fixed cytogenetic cell suspensions or pellets in Carnoy’s fixative; Formalin-fixed, paraffin-embedded tissue.
Extracted DNA is also acceptable if extracted in a CLIA certified laboratory.
Additional Information

By ordering this test the clinician acknowledges that informed consent has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test may include microdissection billed as a separate additional charge. Test includes pathologist interpretation of results billed as a separate additional charge. This test is not available without interpretation.

Billing
CPT Code
81120, 81121, 88381-TC (if applicable)
Fee Code
NA087, NA088, NA037 (if applicable)
Pro Fee CPT
G0452-26, 88381-26 (if applicable)
Prior Authorization
The Prior Authorization form is required for this test. Click here to download the PDF.
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