Near-haploid common acute lymphoblastic leukaemia of childhood with a second hyperdiploid line: a DNA ploidy and fluorescence in-situ hybridization study

Br J Haematol. 1998 Dec;103(3):750-5. doi: 10.1046/j.1365-2141.1998.01044.x.

Abstract

Near-haploidy is a rare cytogenetic finding in childhood acute lymphoblastic leukaemia (ALL) and is associated with a poor prognosis. A second hyperdiploid line, occurring presumably by endoreduplication of the near-haploid stemline, is often observed. We present a case of common ALL in relapse characterized morphologically by a dual population of small and large lymphoblasts. Cytogenetic analysis supplemented with fluorescence in-situ hybridization (FISH) studies localized near-haploidy and hyperdiploidy to the small and large blast population respectively. DNA ploidy determination confirmed two abnormal clones with near-haploidy as the predominant one. A novel t(9;12)(q11;q13) was present in the near-haploid clone and was duplicated in the hyperdiploid clone. This finding identified cells bearing near-haploidy to be the clonogenic population following malignant transformation and confirmed endoreduplication as the mechanism for the presence of associated hyperdiploidy.

Publication types

  • Case Reports

MeSH terms

  • Child
  • Chromosomes, Human, Pair 12 / genetics
  • Chromosomes, Human, Pair 9 / genetics
  • Clone Cells
  • DNA, Neoplasm / genetics*
  • Diploidy*
  • Female
  • Haploidy*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Karyotyping
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / genetics*
  • Translocation, Genetic

Substances

  • DNA, Neoplasm