The recurrent t(12;21)(p12;q22) translocation fuses two genes, TEL and
AML1, that have previously been shown to be independently involved in
myeloid malignant proliferations. A search for rearrangement of the T
EL locus in the region known to be involved in t(12;21) was performed
by Southern blotting in a panel of hematopoietic malignancies. The pre
sence of a t(12;21) was confirmed by fluorescence in situ hybridizatio
n (RSH) and/or reverse transcriptase (RT)-polymerase chain reaction (P
CR). We report that fusion of TEL to AML1 is specifically observed in
at least 16% of the childhood B-lineage acute lymphoblastic leukemia (
ALL) investigated, none of which had been previously identified as har
boring t(12;21). (C) 1995 by The American Society of Hematology.