IDH1 and IDH2 Mutation Analysis Exon 4, Formalin-Fixed, Paraffin-Embedded (FFPE) Tissue (Change effective as of 05/20/24: Refer to 3017222)

Casandra

Casandra Test Code AR70800Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 3004267CPT Codes 81120, 81121

IDH1 and IDH2 Mutation Analysis Exon 4, Formalin-Fixed, Paraffin-Embedded (FFPE) Tissue (Change effective as of 05/20/24: Refer to 3017222)

Also known as: IDH12FFPE

Clinical Use

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Use

This assay detects hotspot mutations in exon 4 of the IDH1 (NM_005896.3) and IDH2 (NM_002168.3) genes, which are clinically relevant in certain solid tumors—including central nervous system tumors and cholangiocarcinoma—for purposes of diagnosis, prognosis, and eligibility for targeted therapies. It covers key hotspots in exon 4 only and is intended for tumor tissue specimens processed as formalin‑fixed, paraffin‑embedded (FFPE).

Special Instructions

Not provided.

Limitations

This test only detects single-nucleotide variants in the targeted hotspot regions of exon 4 of IDH1 and IDH2 and does not detect variants outside those regions or other types of alterations such as copy number changes, translocations, infiltrative rearrangements, methylation, tumor mutational burden, or RNA-level variants. Variants below the limit of detection (10% variant allele frequency) may not be detected. Tissue with low tumor cellularity, poorly preserved or decalcified (except EDTA) specimens may yield suboptimal results or require disclaimers or additional review. Variants classified as benign or likely benign are not reported; variant allelic fraction is not reported. Results must be interpreted in context of clinical and pathological findings.

Test Details

Methodology

NGS (Targeted)

Biomarkers

IDH1, IDH2

Gene

SNV/Indel

Mutation • Categorical (e.g., Positive / Negative / Indeterminate)

LOINC Codes

Order Codes

57723-9 - Unique bar code # Current sample

Result Codes

35474-6 - Gene XXX Mut Anl Bld/T

Result Turnaround Time

10-15 days

Specimen

Tissue (FFPE)

Volume

Not provided

Minimum Volume

Not provided

Collection Instructions

Formalin-fixed (10% neutral buffered formalin, not decalcified) paraffin-embedded tumor tissue with ≥20% tumor burden; submit tissue block or 8 unstained 5‑micron slides (min: 5). New York clients: 10 unstained non‑baked slides plus 1 H&E-stained slide. Include surgical pathology report. Multiple blocks/slides require pathologist block selection instructions or separate orders.