RESUMO
We report the case of a 61-year-old Canadian male of Maltese descent investigated for unexplained polycythemia. Decreased p50 suggested the presence of a high oxygen affinity hemoglobin (Hb) variant. Molecular genetic testing demonstrated that he carries a novel missense mutation (HBB: c.258T>G), resulting in a PheâLeu substitution at position 85 of the ß chain. The novel Hb variant has been designated Hb Kennisis in recognition of where the proband resides. Two other missense mutations have been reported at this position [Hb Bryn Mawr or Hb Buenos Aires, ß85(F1)PheâSer (HBB: c.257T>C); Hb Grantham, ß85(F1)PheâCys; (HBB: c.257T>G)], both of which have increased oxygen affinity.
Assuntos
Hemoglobinas Anormais/genética , Mutação de Sentido Incorreto , Oxigênio/metabolismo , Policitemia/genética , Globinas beta/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Hemoglobinas Anormais/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Policitemia/sangue , Policitemia/diagnóstico , Policitemia/fisiopatologia , Ligação Proteica , Globinas beta/metabolismoRESUMO
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy. It is associated with poor prognosis and heterogenous presentation. The CD123-directed cytotoxin, Tagraxofusp, is a targeted therapy for BPDCN. Here, we report an 81-year-old female diagnosed with BPDCN. The patient was treated with Tagraxofusp and underwent a remarkably long remission (>20 months) without stem-cell transplantation. She, however, experienced blue toe syndrome and left foot gangrene. We postulate that these previously unreported side effects were caused by microembolization. Characterization of the incidence of thrombo- and microembolizations in such a context, as well as prophylactic management options, are warranted.