A Balanced Robertsonian Translocation in a Patient with a Janus Kinase 2-Positive Polycythemia Vera

A male patient with a persistent, combined erythrocytosis, leukocytosis, and thrombocytosis without representative evidence of reactive increase emerged as having a myeloproliferative disorder. Molecular-biological assessment yielded Janus kinase 2-positive results, and the patient was diagnosed with polycythemia vera. In addition to these findings, further karyotyping accounted for a Robertsonian translocation. Because this rearrangement was a balanced variant, we concluded that this cytogenetic result might not significantly alter the diagnosis of polycythemia vera.