Test Code IDHQ IDH1 (R132) and IDH2 (R140 and R172) Quantitative Detection, Droplet Digital PCR, Varies
Shipping Instructions
1. Refrigerated specimens must arrive within 14 days of collection, and ambient specimens must arrive within 7 days of collection.
2. Collect and package specimen as close to shipping time as possible.
Necessary Information
The following information is required:
1. Pertinent clinical history
3. Specimen source (blood or bone marrow)
Specimen Required
Submit only 1 of the following specimens
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD-B) or green top (heparin)
Specimen Volume: 4mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
3. Label specimen as blood.
Specimen Stability: Refrigerated 14 days/ Ambient 7 days
Specimen Type: Bone marrow aspirate
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD-B) or green top (heparin)
Specimen Volume: 2mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Send bone marrow specimen in original tube. Do not aliquot.
3. Label specimen as bone marrow.
Specimen Stability: Refrigerated 14 days/ Ambient 7 days
Specimen Type: Extracted DNA from blood or bone marrow
Container/Tube: 1.5- to 2-mL tube with indication of volume and concentration of DNA
Specimen Volume: Entire specimen
Collection Instructions:
1. Label specimen as extracted DNA and source of specimen
2. Indicate volume and concentration of DNA on label. The required volume of DNA is at least 50 mcL at a concentration of 50 ng/mcL
Specimen Stability: Frozen (preferred)/Refrigerated
Forms
1. Hematopathology Patient Information (T676)
2. If not ordering electronically, complete, print, and send an Hematopathology/Cytogenetics Test Request (T726) with the specimen.
Useful For
Detecting IDH1 R132 and IDH2 R140 and R172 mutations in acute myeloid leukemia patients at the time of diagnosis to guide targeted therapy
Monitoring minimal residual disease during the clinical and therapeutic course
Special Instructions
Method Name
Droplet Digital Polymerase Chain Reaction (ddPCR)
Reporting Name
IDH1 and IDH2, Quant, ddPCR, VSpecimen Type
VariesSpecimen Minimum Volume
Whole blood: 4mL
Bone marrow: 2mL
Extracted DNA: 50 mcL at 50 ng/mcL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Refrigerated (preferred) | 14 days | |
Ambient | 7 days |
Reference Values
An interpretive report will be provided.
Interpretation
The assay is reported as positive or negative. In positive cases, the mutation and its variant allele fraction (VAF) are reported.
VAF%= (mutant copy number)/(mutant copy number + wild-type number)
The precision of this quantitative assay is excellent but interassay variability may occur such that result changes should not be considered significant if 2 single measurements differ by less than 0.5 log (3.16-folds).
Clinical Reference
1. US Food and Drug Administration (FDA): Table of Pharmacogenomic Biomarkers in Drug Labeling. FDA; Updated March 29, 2022, Accessed August 3, 2022. Available at www.fda.gov/drugs/science-and-research-drugs/table-pharmacogenomic-biomarkers-drug-labeling
2. US Food and Drug Administration (FDA): FDA granted regular approval to enasidenib for the treatment of relapsed or refractory AML. FDA; August 1, 2017. Accessed August 10, 2022. Available at www.fda.gov/drugs/resources-information-approved-drugs/fda-granted-regular-approval-enasidenib-treatment-relapsed-or-refractory-aml
3. Yang H, Ye D, Guan KL, Xiong Y: IDH1 and IDH2 mutations in tumorigenesis: mechanistic insights and clinical perspectives. Clin Cancer Res. 2012 Oct;18(20): 5562-5571
4. Dohner H, Weisdorf DJ, Bloomfield CD: Acute myeloid leukemia. N Engl J Med. 2015 Sept;373(12):1136-1152
5. McKenney AS, Levine RL: Isocitrate dehydrogenase mutations in leukemia. J Clin Invest.2013 Sep;123(9):3672-3677
6. Pollyea DA: New drugs for acute myeloid leukemia inspired by genomics and when to use them. Hematology Am Soc Hematol Educ Program. 2018 Nov;2018(1):45-50
7. Stein EM, DiNardo CD, Pollyea DA, Fathi AT, et al. Enasidenib in mutant IDH2 relapsed or refractory acute myeloid leukemia Blood. 2017 Aug 10;130(6):722-731.
8. DiNardo CD, Stein EM, de Botton S, et al: Durable remissions with Ivosidenib in IDH1-mutated relapsed or refractory AML. N Engl J Med. 2018 Jun;378(25):2386-2398
9. Ok CY, Loghavi S, Sui D, et al: Persistent IDH1/2 mutations in remission can predict relapse in patients with acute myeloid leukemia. Haematologica 2019;104(2):305-311
Day(s) Performed
Monday through Saturday
Report Available
4 to 8 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest 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
81120
81121
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
IDHQ | IDH1 and IDH2, Quant, ddPCR, V | 95772-0 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
MP063 | Specimen Type | 31208-2 |
618389 | Interpretation | 69047-9 |
618390 | Signing Pathologist | 18771-6 |