IRF4/DUSP22 (6p25) Gene Rearrangement by FISH

Casandra

Casandra Test Code AR35991Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 3001568CPT Code 88366

IRF4/DUSP22 (6p25) Gene Rearrangement by FISH

Also known as: IRF4 FISH

Clinical Use

Order Test

Use

The IRF4/DUSP22 (6p25) Gene Rearrangement by FISH test is designed to detect IRF4 and DUSP22 rearrangements, which are relevant for the diagnosis and prognosis of B-cell and T-cell lymphomas. This assay is crucial for identifying translocations involving chromosome region 6p25, a known marker for non-Hodgkin lymphomas. The test employs fluorescence in situ hybridization (FISH) to analyze paraffin-embedded tissue sections, selecting areas for analysis through histopathologic review.

Special Instructions

Not provided.

Limitations

The test is expected to detect 100% of IRF4 rearrangements except for very rare instances of cryptic rearrangements. Approximately 12% or more cells showing abnormal signal patterns indicate a positive result, although other non-classical abnormal patterns might also be present. Results may be affected by the quality of the specimen and should be correlated with morphologic, clinical, and immunophenotypic data to ensure accurate interpretation. The test uses fluorescent probes that target upstream and downstream regions flanking IRF4/DUSP22 genes, ensuring specificity but limiting its use to prepared tumor tissue sections.

Test Details

New York Approved

Methodology

Chromosomal / Cytogenetics (FISH)

Biomarkers

No genes

Gene

FISH Analysis

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

LOINC Codes

Result Codes

81304-8 - Struct var analysis method
94736-6 - Tissue block ID Spec
31208-2 - Specimen source
48674-6 - Genetic diseases Bld/T FISH
19076-9 - Total Cells Counted Spec

Result Turnaround Time

3-7 days

Specimen

Tumor Tissue (FFPE)

Volume

Not provided

Minimum Volume

4 slides

Container

Positively charged glass slides or tissue block

Collection Instructions

Formalin fix (10 percent neutral buffered formalin) and paraffin embed tumor tissue. Transport tissue block or 4 unstained, consecutively cut, 5-micron thick sections, mounted on positively charged glass slides.

Storage Instructions

Protect paraffin block and/or slides from excessive heat.

Causes for Rejection

Specimens fixed in any fixative other than 10 percent neutral buffered formalin, decalcified specimens, or paraffin block with no tumor tissue remaining.