Use of test
A group of myeloid and lymphoid diseases associated with eosinophilia can result from aberrant tyrosine kinase expression. These related disorders are associated with PDGFRA, PDGFRB or FGFR1 rearrangements. These rearrangements have prognostic and therapeutic implications.
Identification of these rearrangements can establish diagnosis and give information regarding therapy (for example, imatinib for patients with PDGFRA or PDGFRB rearrangements).
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 PDGFRA, PDGFRB or FGFR1 with a partner gene. The breakpoints involved in these fusions can be variable, and in some cases certain variants will not be detected by the probe.
Requesting the test
This test is usually requested by a haematologist or oncologist.
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.
5 business days.
PDGFRA testing has a Medicare rebate which, subject to the requirements of the Medicare descriptor being met, may cover all or part of the cost.
The Medicare details, including descriptor and schedule fee, are listed under MBS item 73326.