Abstract

The 8p11 myeloproliferative syndrome (EMS) is an aggressive hematological malignancy caused by the fusion of diverse partner genes to fibroblast growth factor receptor 1 (FGFR1). The partner proteins promote dimerization and ligand-independent activation of FGFR1-encoded tyrosine kinase, deregulating hemopoiesis in a manner analogous to BCR-ABL in chronic myeloid leukemia. Here, we describe the identification of a new FGFR1 fusion gene in a patient who presented with T-cell lymphoblastic lymphoma in conjunction with an acquired ins(12;8)(p11;p11p22). Initial FISH analysis and Southern blotting confirmed that FGFR1 was disrupted. Using 5'-RACE PCR, we identified part of a novel gene, FGFR1OP, at chromosome band 12p11 that was fused to exon 9 of FGFR1.FGFR1OP2 is predicted to be translated into an evolutionarily conserved protein containing coiled-coil domains but no other recognizable motifs. The presence of the chimeric gene was confirmed by RT-PCR, genomic DNA PCR, and FISH. These data further support the central role of deregulated FGFR1 in the pathogenesis of EMS.