The TEL-AML1 fusion gene is associated with a cryptic t(12:21)(p12:q22) translocation, and is the commonest known genetic abnormality in childhood B-cell precursor acute lymphoblastic leukaemia (ALL), occurring in about 25% of cases.     ///    "We conclude that the TEL-AML1 fusion gene is found in adult ALL, though less commonly than in children.. "    ///    "We have used RT-PCR, followed by Southern blotting and direct sequencing, to establish the incidence of TEL-AML1 rearrangement in 131 adults with acute leukaemia (101 with ALL and 30 with chronic myeloid leukaemia in blastic crisis). "    ///    Three patients were positive for TEL-AML1 transcripts.     ///    All other patients were negative for TEL-AML1.     ///    TEL-AML1 fusion in acute lymphoblastic leukaemia of adults. 