%0 Case Reports
%T Colony-Forming Cell Assay Detecting the Co-Expression of JAK2V617F and BCR-ABL1 in the Same Clone: A Case Report.
%A Tirrò E
%A Stella S
%A Massimino M
%A Zammit V
%A Pennisi MS
%A Vitale SR
%A Romano C
%A Di Gregorio S
%A Puma A
%A Di Raimondo F
%A Stagno F
%A Manzella L
%J Acta Haematol
%V 141
%N 4
%D 2019
%M 30965317
%F 3.068
%R 10.1159/000496821
%X BCR-ABL1-negative myeloproliferative disorders and chronic myeloid leukaemia are haematologic malignancies characterised by single and mutually exclusive genetic alterations. Nevertheless, several patients co-expressing the JAK2V617F mutation and the BCR-ABL1 transcript have been described in the literature. We report the case of a 61-year-old male who presented with an essential thrombocythaemia phenotype and had a subsequent diagnosis of chronic phase chronic myeloid leukaemia. Colony-forming assays demonstrated the coexistence of 2 different haematopoietic clones: one was positive for the JAK2V617F mutation and the other co-expressed both JAK2V617F and the BCR-ABL1 fusion gene. No colonies displayed the BCR-ABL1 transcript alone. These findings indicate that the JAK2V617F mutation was the founding genetic alteration of the disease, followed by the acquisition of the BCR-ABL1 chimeric oncogene. Our data support the hypothesis that a heterozygous JAK2V617F clone may have favoured the bi-clonal nature of this myeloproliferative disorder, generating clones harbouring a second transforming genetic event.