Molecular data of two other Ph1 translocations, one a Ph1+bcr- acute myeloblastic leukemia in the bcr2 region, and the other an acute lymphoblastic leukemia in the bcr3 region are presented.
In order to search for mechanisms underlying the reciprocal chromosome translocation, molecular analysis of breakpoints on chromosome 9 and 22 were performed in a Ph1+bcr- acute lymphoblastic leukemia with bcr2 rearrangement.
Thus, the order of loci on chromosome 22 is centromere----BCR2, BCR4, and IGL----BCR1----BCR3----SIS, possibly eliminating BCR2 and BCR4 loci as candidate targets for juxtaposition to the ABL gene in the acute lymphoblastic leukemia Ph1 chromosome.