Use of test
Purpose:
CDKN2A is a tumour suppressor gene. Inactivation of this gene by mutation, methylation or deletion plays a role in the progression of many cancers. Deletions are the most frequent mechanism in haematological malignancies, and these can be detected by FISH. The presence of a deletion can have diagnostic and prognostic implications.
Utility:
CDKN2A deletions occur in up to 21% of B-cell precursor ALL and up to 50% of T-ALL patients. The prognostic effect is uncertain, with deletions possibly being a negative factor in childhood ALL.
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 designed to detect CDKN2A gene deletion. 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%.
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 mL blood in lithium heparin if blasts >10%).
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:
The price varies according to the specific clinical conditions for a particular patient. Please contact Sonic Genetics on 1800 010 447 for more information.
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.