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FUS/DDIT3 FISH

Also known as: t(12;16) FISH

Test category:

Oncology - Sarcoma

Use of test

Purpose:

The t(12;16) translocation results in fusion of the FUS and DDIT3 genes. This test has diagnostic implications.

Utility:

FUS-DDIT3 fusion or variants having FUS rearrangement with other partners are seen in about 90% of myxoid liposarcomas, and can be useful as a diagnostic aid.

Ethical considerations:

This is an assay for non-heritable mutations. It does not raise issues of ethics or consent that are different from most other investigations ordered in the routine care of a patient.

Methodology:

Fluorescent in situ hybridisation (FISH) analysis using probes to detect the FUS-DDIT3 fusion gene. The probes used are individual breakapart probes for FUS and DDIT3, so variants are detected. This test is performed on thin sections of tissue, so some cells in the section may be sliced by the process, and only contain some of the regions of interest. Sections may contain bony, fatty or necrotic material, which may interfere with processing and/or analysis. Dense tissue also makes identification of individual cells difficult. The accuracy of the results is dependent on the correct identification of tumour on the sections provided, and the assumption that positive results will be identified by a large proportion of cells within the tumour having a rearrangement.

Requesting the test

Ordering:

This test is usually requested by an oncologist.

Request form:

Download the solid tumour somatic mutation request form.

Sample required:

Formalin-fixed, paraffin embedded tissue (FFPE) - 15 sections of 4 uM thickness, dried overnight at 37°C onto charged/coated slides.

Special instructions:

Please stain the first section with H&E, and label each slide with patient and block identifiers. Label the unstained sections sequentially (slides 2-15). The request should be accompanied by the somatic mutation request form (above) and a copy of the original histopathology report.

Turnaround time:

5 business days.

Price:

Up to $410.

If more information is required, the requesting clinician can call our laboratory on (07) 3377 8573.

Rebate:

This test is not rebated by Medicare. The laboratory assumes that the patient or client has provided informed financial consent for the test.

Click here for our billing policy.