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Chronic lymphocytic leukaemia FISH panel

Also known as: CLL FISH

Test category:

Oncology - Leukaemia

Use of test

Purpose:

Changes in chromosome structure and number in leukaemic cells can provide important prognostic and therapeutic information in patients with chronic lymphocytic leukaemia (CLL). A panel of probes is used to look for the most frequent abnormalities, 13q deletion, trisomy 12, ATM deletion and TP53 deletion.

Utility:

The laboratory report defines the changes in the patient's malignant cells and relates these changes to the current management recommendations.

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 specific to the relevant targets. This interphase FISH test has a cut off at 5%. A low level of positive cells may be due to overlap of the two signals. Studies of normal controls indicate that this level is less than 5%. Using the TP53 probe, positivity is uncertain between 5 and 10%.

Requesting the test

Ordering:

This test is usually requested by a haematologist or oncologist.

Sample required:

0.5 mL bone marrow in transport media or 10 mL blood in lithium heparin if clinically appropriate.

To help ensure the quality of the test, a genetic test should be done with a dedicated sample whenever possible i.e. a sample collected specifically for that test rather than a sample that is used for multiple tests.

We recommend that the patient or another adult check the labelling of request forms and sample tubes.

Turnaround time:

5 business days.

Price:

$255.

Note that in cases of relapsed or refractory CLL, TP53 deletion testing has a Medicare rebate.

Rebate:

The Medicare details, including descriptor and schedule fee, are listed under MBS item 73343.

Click here for our billing policy.