E1A3 as a unique, naturally occurring BCR-ABL transcript in an indolent case of chronic myeloid leukaemia

A woman with Ph-positive chronic myeloid leukaemia (CAM) with an atypical e 1a3 BCR-ABL hybrid gene is described. To our knowledge, this is the first r eport of this transcript type as a unique naturally occurring BCR-ABL fusio n in a CML patient. This case was characterized by a low leucocyte count an d a very indolent course without treatment. Because the deletion of ABL exo n 2 sequences results in deletion of an essential part of the ABL SH3 domai n, our case suggests that this ABL SH3 domain is not absolutely necessary f or efficient induction of a myeloproliferative disease in the context of BC R-ABL/p190.