Methodology: FISH

Clinical Significance:
The FIP1L1-PDRGFRα fusion is a genetic abnormality found in idiopathic hypereosinophilic syndrome (HES), or primary eosinophilia. HES is a chronic and typically slowly progressive disease that eventually results in organ damage. Several molecular mechanisms have been identified, including FIP1L1-PDGFRα and rearrangements of PDGFRβ and FGFR1. Presence of the FIP1L1-PDGFRα fusion is associated with positive response to imatinib mesylate (Gleevec) therapy. While molecularly defined eosinophilias are relatively rare, approximately one-quarter of HES patients have been shown to harbor this mutation. In these patients, imatinib therapy improves 5-year survival rates to from ~75% to 90-95% and reduces rates of progression from 50% down to less than 1%.

Organ: Blood/Bone Marrow

Disease State:

CPT Code(s): 88374. The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Turnaround Time: Within 4-6 business days of receipt

Schedule: Monday - Friday

Specimen Requirements:
• Peripheral blood, Preferred: 3 ml in sodium heparin (green top) / Acceptable: 3 ml in EDTA (purple top) - OR - • Bone marrow aspirate, Preferred: 1-2 ml in sodium heparin (green top) / Acceptable: 1-2 ml in EDTA (purple top) - OR - • Fresh tissue in RPMI