Also known as: TEL/AML1 FISH, t(12;21) FISH« Back to test list
TEL and AML1 are rearranged by a translocation between chromosomes 12 and 21 in a subset of patients with B-cell acute lymphoblastic leukaemia (ALL). This fusion is more common in the paediatric age group. These two genes are also known as ETV6 and RUNX1 (respectively). The presence of this gene fusion has prognostic implications.
The translocation is not visible cytogenetically. The presence of a TEL-AML1 fusion gene is associated with a good prognosis.
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 to identify fusion of TEL with AML1.
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.