13q14 deletion size and number of deleted cells both influence prognosis in chronic lymphocytic leukemia

Genes Chromosomes Cancer. 2011 Aug;50(8):633-43. doi: 10.1002/gcc.20885. Epub 2011 May 11.


Deletion at 13q14 is detected by fluorescence in situ hybridization (FISH) in about 50% of chronic lymphocytic leukemia (CLL). Although CLL with 13q deletion as the sole cytogenetic abnormality (del13q-only) usually have good prognosis, more aggressive clinical courses are documented for del13q-only CLL carrying higher percentages of 13q deleted nuclei. Moreover, deletion at 13q of different sizes have been described, whose prognostic significance is still unknown. In a multi-institutional cohort of 342 del13q-only cases and in a consecutive unselected cohort of 265 CLL, we investigated the prognostic significance of 13q deletion, using the 13q FISH probes locus-specific identifier (LSI)-D13S319 and LSI-RB1 that detect the DLEU2/MIR15A/MIR16-1 and RB1 loci, respectively. Results indicated that both percentage of deleted nuclei and presence of larger deletions involving the RB1 locus cooperated to refine the prognosis of del13q-only cases. In particular, CLL carrying <70% of 13q deleted nuclei with deletions not comprising the RB1 locus were characterized by particularly long time-to-treatment. Conversely, CLL with 13q deletion in <70% of nuclei but involving the RB1 locus, or CLL carrying 13q deletion in ≥70% of nuclei, with or without RB1 deletions, collectively experienced shorter time-to-treatment. A revised flowchart for the prognostic FISH assessment of del13q-only CLL, implying the usage of both 13q probes, is proposed.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Deletion
  • Chromosome Disorders / genetics*
  • Chromosomes, Human, Pair 13 / genetics
  • Cohort Studies
  • Humans
  • In Situ Hybridization, Fluorescence / methods
  • Leukemia, Lymphocytic, Chronic, B-Cell / genetics*
  • Leukemia, Lymphocytic, Chronic, B-Cell / pathology
  • Prognosis
  • RNA, Long Noncoding
  • Retinoblastoma Protein / genetics
  • Sequence Deletion
  • Transferases
  • Tumor Suppressor Proteins / genetics


  • DLEU2 lncRNA, human
  • RNA, Long Noncoding
  • Retinoblastoma Protein
  • Tumor Suppressor Proteins
  • Transferases

Supplementary concepts

  • 13q deletion syndrome