Use of test
Purpose:
Deletions affecting the long arm of Chromosome 6, including the 6q21 region, are common in mature B-cell lymphoid neoplasms, for example, plasma cell neoplasms, mantle cell lymphoma, and B-cell non-Hodgkin lymphoma, particularly lymphoplasmacytic lymphoma. These deletions can assist in subsequent monitoring of disease.
Utility:
Presence of a 6q21 deletion is not prognostically significant, but can be a marker for presence of a monoclonal population, or for quantitative population size estimation.
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 located at 6q21. 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%. Small abnormal populations may therefore not be detectable.
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 5-10 mL blood in lithium heparin.
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:
Up to $255.
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.