Cytogenetic rearrangements of the long arm of chromosome 3 in myeloid neoplasms — descriptions of three cases

Abstract

Aberrant rearrangements in the 3q26 and 3q21 regions on the long arm of chromosome 3 havebeen observed in many conditions, including de novo acute myeloid leukemia (AML), in AML with antecedent myelodysplastic syndrome (MDS), as well as in MDS itself, the blastic phase of chronic myelogenous leukemia (BP-CML) and also in other myeloproliferative neoplasms (MPN). Such cytogenetic aberrations lead to abnormal expression of the RPN1-EVI1 fusion gene transcripts which involve the ecotropic viral integration site-1 (EVI1) at 3q26 and ribophorin I (RPN1) at3q21; these playing important roles in leukemogenesis and disease progression. Three case studies are presented of patients with the self same rearrangements on the long arm of chromosome 3. The first patient presented with de novo AML and t(3;3) (q21;q26) who, in spite of having double allogeneic hematopoietic stem cell transplantations, had fatal outcome. The other two patients had MPN. One was initially diagnosed with CML and whilst being treated with imatinib, the t(3;3) abnormality was nevertheless acquired even though at first the treatment had been effective. Despite subsequent second line treatment with dasatinab, the leukemia progressed with the appearance of extramedullary infiltration. The second patient developed AML with inv(3) after essential thrombocythaemia had been diagnosed 10 years ago. At first, the patient went into complete remission following induction chemotherapy with daunorubicine and cytarabine. This therapy was howeverre-implemented, when disease progression had again occurred during further observation. The patient then unfortunately developed pneumonia and died before hematopoietic recovery. These clinical findings thus indicate that cytogenetic aberrations on the long arm of chromosome 3 predict a poor outcome in patients with myeloid neoplasms.