IDH1 and IDH2 Hotspot PCR Analysis Tissue
Test Mnemonic
IDHID
CPT Codes
- 81120 - QTY (1)
- 81121 - QTY (1)
Aliases
- Isocitrate dehydrogenase 1
- Isocitrate dehydrogenase 2
- IDH 1 & 2
- IDH1-2
- IDH12
- IDH12G
Performing Laboratory
Cleveland Clinic Laboratories
FDA Category
Laboratory Developed Test
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 10 mm square | Block, Formalin fixed paraffin | Formalin-fixed, paraffin-embedded block | Ambient | Ambient | Formalin-fixed paraffin-embedded tissue slides. Transport and store slides at ambient temperature. Three unstained sections FFPE tissue on charged, unbaked slides or scrolls, plus one H&E stained section with best tumor area circled by a pathologist. Provide the percentage of tumor cells present, minimum of 10%. |
Stability
| Environmental Condition | Description |
|---|---|
| Refrigerated | Collect at ambient and transport at ambient or refrigerated temperature |
| Ambient | Collect and transport at ambient temperature |
| Frozen | Unacceptable |
Days Performed
Mon - Fri
Turnaround Time
3 days
Methodology
| Name | Description |
|---|---|
| Real-Time Polymerase Chain Reaction (RT-PCR) |
Special Info
This assay looks for select hotspot mutations in IDH1 codon 132 and IDH2 codons 140 and 172
Clinical Info
The IDH1 and IDH2 Hotspot PCR Analysis rapidly identifies specific mutations in solid and liquid tumors, guiding diagnosis, prognosis, and treatment planning. The IDH1 and IDH2 Hotspot PCR Analysis rapidly detects 15 biomarkers, including clinically relevant, activating mutations in IDH1 codon 132 and IDH2 codons 140 and 172, using real-time PCR technology. IDH1 and IDH2 hotspot mutation testing is indicated in several neoplasms, including acute myeloid leukemia, glioma, chondrosarcoma, and cholangiocarcinoma, to determine eligibility for targeted therapy. This test only detects hotspot mutations in IDH1 and IDH2 and should be considered when IDH1 and IDH2-only targeted testing is required, when tumor material is limited, and/or rapid turnaround time is necessary. For more comprehensive hematological neoplasm testing, please refer to the Acute Leukemia and Hematological Neoplasm panels. For more comprehensive solid tumor testing, please refer to the Targeted Oncology Panel.
Clinical Limitation
The assay limit of detection (LOD) is 5% variant allele fraction. Specimens must contain at least 10% tumor cells; if less than 10% tumor is utilized, a negative result is of indeterminate significance. Only 5 IDH1 and 10 IDH2 variants can be detected by this technology; refer to the gene list on the Supporting Document tab for specific details. A negative result does not preclude the possibility of an alternative hotspot variant. Tumor heterogeneity, tumor burden, specimen degradation, or other technology limitations may affect the sensitivity and LOD. Interfering substances, specifically formalin, decalcification agents, fixation agents containing heavy metals, or preservation of buffy coats using Hank’s Balanced Salt Solution (HBSS) can potentially affect assay performance. This test cannot distinguish between somatic and germline variants.