Alternate Test Names:
PDGFRA, PDGFRA-FIP1L1 fusion, CHIC2 deletion, 4q12

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

Turnaround Time: Within 3-4 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