Recurrence of OTT–MAL fusion in t(1;22) of infant AML-M7


  • Thomas Mercher and Florence Nguyen Khac are recipients of fellowships from the Ministère de l'education Nationale and the Académie Nationale de Médecine, respectively.


Translocation t(1;22)(p13;q13) is associated with a peculiar subtype of acute megakaryocytic leukemia (M7) occurring in infants. We have recently characterized a fusion gene, OTT–MAL, resulting from this translocation. We now report three additional cases and show that this gene fusion is present in all five t(1;22) cases studied to date. Nucleotide sequence analysis of two translocation breakpoints suggests a nonhomologous end joining mechanism in the genesis of this translocation and reveals a noncanonical topoisomerase II-like consensus sequence within the OTT gene. FISH and PCR techniques described in this work are useful for identifying t(1;22) associated with M7.