Translocation (1;20)(q32;q13.3) in myelofibrosis following polycythemia vera.

We report a novel chromosomal translocation (1;20)(q32;q13.3) in a patient with myelofibrosis following polycythemia vera. This 73-year-old woman developed myelofibrosis 6 years after the initial diagnosis of polycythemia vera (PV). The course of PV was uneventful. Subsequent to the diagnosis, the patient was treated with phlebotomy and low doses of hydroxyurea for 4 years. No therapy was delivered during the remaining 2 years. A bone-marrow biopsy and a karyotype analysis performed because of evolving anemia demonstrated myelofibrosis and a chromosomal aberration-t(1;20)(q32;q13.3). Aberrations in chromosomes 1 and 20 have been reported in myeloproliferative disorders, but a t(1;20) translocation has not been reported. Because a karyotype analysis was not performed at the time PV was diagnosed, whether this translocation is linked to the primary disease (PV) or to the transition to myelofibrosis is not known.