Trisomy 12 FISH
Also known as: Trisomy 12 FISH« Back to test list
Trisomy of chromosome 12 is the most common cytogenetic abnormality in patients with chronic lymphocytic leukaemia (CLL), and can be found in other mature B-cell neoplasms. This cytogenetic abnormality has prognostic implications.
Presence of trisomy 12 is associated with a low risk of progression in CLL.
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.
Fluorescent in situ hybridisation (FISH) analysis, using probes specific to chromosome 12.
This test is usually requested by a haematologist or oncologist.
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 also recommend that the patient or another adult check the labelling of request forms and sample tubes.