The 4q12 probe is located on chromosome 4. A 700 Kb probe covering the SCFD gene region is labeled with a green dye. A 450 Kb probe covering the 3′ end of the FIP1L1 gene region is labeled with an orange dye. A 770 Kb probe covering the KIT gene region is labeled with an aqua dye.

Detects FIP1L1/PDGFRA fusions and CHIC2 deletions at 4q12 in myeloid neoplasms associated with eosinophilia.

Used for diagnosing PDGFRA abnormalities critical for therapeutic intervention and WHO classification. Identifies chromosomal breaks within PDGFRA including translocations or interstitial deletions resulting in FIP1L2-PDGFRA fusion.