Translocation (4;15)(p16;q24): A novel reciprocal translocation in a patient with BCR/ABL negative myeloproliferative syndrome progressing to blasticphase

A patient with BCR/ABL negative myeloproliferative syndrome with a 46,XY,de l(3)(q21), t(4;15)(p16;q24) karyotype is described. Fluorescence in situ hy bridization performed with chromosomes 4 and 15 painting probes confirmed a novel reciprocal (4;15) translocation. The absence of crkl tyrosine phosph orylation, no activation of the abl kinase as measured by autophosphorylati on, and a normal-size abl transcript suggest an alternative mechanism for l eukemogenesis to that operative in Ph positive BCR/ABL positive chronic mye loid leukemia. A number of genes potentially relevant to tumorigenesis, som e involving the ras signaling path ways map to the 4p16 and 15q24 chromosom e regions. (C) Elsetier Science Inc., 1999. All rights reserved.