We identified a novel fusion gene, FOXP1-PDGFRA, in a patient with myeloproliferative neoplasm (MPN) with eosinophilia, harboring the chromosome abnormalityt(3;4)(p13;q12).
Examination for the common eosinophilia-related cytogenetic abnormalities involving the genes PDGFRA, PDGFRB, and FGFR1 together with BCR-ABL fusion gene was negative.
The myeloid and lymphoid neoplasms with eosinophilia and PDGFRA gene rearrangements usually show a good response to Imatinib and are typically associated with a normal karyotype, occasionally exhibiting a secondary chromosomal abnormality associated with clonal evolution.
Altogether, PDGFRA-mutated GISTs display the same chromosomal aberrations as KIT-mutated GISTs, although they have a lower degree of chromosomal instability in line with their generally favorable outcome.