Precursor-B-ALL With D(H)-J(H) Gene Rearrangements Have an Immature Immunogenotype With a High Frequency of Oligoclonality and Hyperdiploidy of Chromosome 14

Leukemia. 2001 Sep;15(9):1415-23. doi: 10.1038/sj.leu.2402206.

Abstract

The IGH gene configuration was investigated in 97 childhood precursor-B-ALL patients at initial diagnosis. Rearrangements were found by Southern blotting in all but three patients (97%) and in 30 cases (31%) we observed oligoclonal IGH gene rearrangements. Heteroduplex PCR analysis revealed at least one clonal PCR product in all Southern blot-positive cases. In 89 patients (92%) complete V(D)J rearrangements were found, while incomplete D(H)-J(H) rearrangements occurred in only 21 patients (22%). In 5% of cases the D(H)-J(H) rearrangements were the sole IGH gene rearrangements. Sequence analysis of the 31 identified incomplete rearrangements revealed preferential usage of segments from the D(H)2, D(H)3 and D(H)7 families (78%). While D(H)2 and D(H)3 gene rearrangements occur frequently in normal B cells and B cell precursors, the relatively frequent usage of D(H)7-27 (19%) in precursor-B-ALL patients is suggestive of leukemic transformation during prenatal lymphopoiesis. Among J(H) gene segments in the incomplete D(H)-J(H) rearrangements, the J(H)6 segment was significantly overrepresented (61%). This observation together with the predominant usage of the most upstream D(H) genes indicates that many of the identified clonal D(H)-J(H) gene rearrangements in precursor-B-ALL probably represent secondary recombinations, having deleted pre-existing D(H)-J(H) joinings. The patients with incomplete D(H)-J(H) gene rearrangements were frequently characterized by hyperdiploid karyotype with additional copies of chromosome 14 and/or by IGH oligoclonality. The presence of incomplete D(H)-J(H) joinings was also significantly associated with a less mature immunogenotype: overrepresentation of V(H)6-1 gene segment usage, absence of biallelic TCRD deletions, and low frequency of TCRG gene rearrangements. This immature immunogenotype of precursor-B-ALL with incomplete IGH gene rearrangements was not associated with more aggressive disease.

MeSH terms

  • Adolescent
  • Blotting, Southern
  • Child
  • Child, Preschool
  • Chromosomes, Human, Pair 14*
  • Gene Rearrangement, B-Lymphocyte, Heavy Chain / genetics*
  • Genes, Immunoglobulin / genetics*
  • Genotype
  • Heteroduplex Analysis
  • Humans
  • Immunogenetics
  • Immunoglobulin Joining Region / genetics*
  • Infant
  • Leukemia, B-Cell / genetics*
  • Neoplasm, Residual / genetics
  • Polymerase Chain Reaction

Substances

  • Immunoglobulin Joining Region