del(12)(q24q24) SETD1B/GTF2H3

We identified a novel SETD1B/GTF2H3 fusion gene in a polycythemia vera (PV) patient with complex karyotype, harboring a cryptic deletion involving chromosome band 12q24.31. This rearrangement led to the juxtaposition of the SETD1B (SET domain containing 1B) gene at intron 11 (chr12:122,257,801) with the GTF2H3 (general transcription factor IIH, polypeptide 3) gene at intron 5 (chr12:124,137,254). In silico translation showed a protein retaining SETD1B RNA binding domain (RRM_S) at its N-terminus and a portion of GTF2H3 DNA binding domain (Tfb4) at its C-terminus. We also provided evidences that SETD1B might be rearranged in an additional PV case, although in a small proportion of hematopoietic cells, indicating a possible role of SETD1B in disease pathogenesis.