The FIP1L1-PDGFRa (Fip1-like-1 fused with platelet derived growth factor receptor alpha) FISH probe detects an interstitial deletion on chromosome 4q12 (including CHIC2) which results in the formation of the FIP1L1-PDGFRa fusion gene. This fusion leads to an activated tyrosine kinase receptor which can be inhibited by imatinib (Gleevec®).
The diagnosis of hypereosinophilic syndrome (HES) has been largely a process of exclusion and therefore unsatisfactory. Many clinical conditions may cause varying degrees of ypereosinophilia, including idiopathic hypereosinophilic syndrome, chronic eosinophilic leukemia and systemic mast cell disease with hypereosinophlia. In some patients these diseases are associated with the FIP1L1-PDGFRa fusion, and therefore respond well to treatment with imatinib (Gleevec®). Although HES is relatively rare, accurate diagnosis can identify patients who may be treated effectively.
CPT Codes:
88271(1), 88275(1), 88291(1)
Specimen Requirements:
Bone Marrow Aspirate:
- The test is typically performed on bone marrow specimens, along with flow cytometry and cytogenetics.
- If requested alone, 1-3 ml bone marrow or 5-7 ml peripheral blood in a sodium heparin (green-top) tube is required.
Turnaround Time:
1-3 days, 7-10 days when ordered with cytogenetics
Client Services:
Oncology/Pathology
800-447-5816
Specimen Services/Pickup:
877-246-1226
Gleevec® is a registered trademark of Novartis AG.