TEL/AML1 fusion resulting from a cryptic t(12;21) is the most common genetic lesion in pediatric ALL and defines a subgroup of patients with an excellent prognosis

Leukemia. 1995 Dec;9(12):1985-9.

Abstract

The t(12;21)(p13;q22) is identified by routine cytogenetics in less than 0.05% of pediatric acute lymphoblastic leukemia (ALL) patients. This translocation encodes a TEL/AML-1 chimeric product comprising the helix-loop-helix domain of TEL, a member of the ETS-like family of transcription factors, fused to AML-1, the DNA-binding subunit of the AML-1/CBF beta transcription factor complex. Both TEL and AML-1 are involved in several myeloid leukemia-associated translocations with AML-1/CBF beta being altered in 20-30% of de novo acute myeloid leukemia (AML) cases. We now demonstrate that a TEL/AML1 chimeric transcript encoded by a cryptic t(12;21) is observed in 22% of pediatric ALL, making it the most common genetic lesion in these patients. Moreover, TEL/AML1 expression defined a distinct subgroup of patients characterized by an age between 1 and 10 years, B lineage immunophenotype, non-hyperdiploid DNA content and an excellent prognosis. These data demonstrate that molecular diagnostic approaches are invaluable in identifying clinically distinct subgroups, and that the AML1/CBF beta transcription complex is the most frequent target of chromosomal rearrangements in human leukemia.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • Child
  • Child, Preschool
  • Chromosomes, Human, Pair 12
  • Chromosomes, Human, Pair 21
  • Core Binding Factor Alpha 2 Subunit
  • DNA-Binding Proteins / genetics*
  • Humans
  • Molecular Sequence Data
  • Neoplasm Proteins / genetics*
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / genetics*
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / metabolism
  • Prognosis
  • Proto-Oncogene Proteins c-ets
  • Proto-Oncogene Proteins*
  • Recombinant Fusion Proteins / genetics*
  • Repressor Proteins*
  • Transcription Factors / genetics*
  • Translocation, Genetic*

Substances

  • Core Binding Factor Alpha 2 Subunit
  • DNA-Binding Proteins
  • ETS translocation variant 6 protein
  • Neoplasm Proteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-ets
  • RUNX1 protein, human
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Transcription Factors