Molecular rearrangement of the ALL-1 gene in acute myeloid leukemia without cytogenetic evidence of 11q23 chromosomal translocations.

Translocations which involve chromosome band 11q23 are frequently found in infants and adults with acute myeloid leukemia (AML) or acute lymphoblastic leukemia. We previously cloned a gene called ALL-1 which spans the 11q23 breakpoint and is rearranged in most cases of leukemia with 11q23 abnormalities. In the present report, we have investigated the occurrence of ALL-1 rearrangement in cases of AML without cytogenetic evidence of 11q23 abnormalities. We detected molecular rearrangements of the ALL-1 gene in 3 of 4 patients with de novo AML and trisomy 11 as a sole chromosomal abnormality. Furthermore, we found DNA rearrangements of ALL-1 in 2 of 19 patients with de novo AML and normal cytogenetics. We conclude that molecular rearrangement of ALL-1 often can be detected in de novo AML, despite the absence of cytogenetic abnormalities involving 11q23.