Deletion 5q in myelodysplastic syndrome: a paradigm for the study of hemizygous deletions in cancer

Leukemia. 2009 Jul;23(7):1252-6. doi: 10.1038/leu.2009.53. Epub 2009 Mar 26.


Hemizygous deletions are common molecular abnormalities in cancer. In some cases, these deletions highlight chromosomal loci containing tumor suppressor genes that undergo homozygous inactivation. In other cases, hemizygous deletions cause disease by allelic insufficiency for one or more genes. As the intact allele has no identifiable lesions, functional approaches are critical for the identification of pathogenic genes within large deletions. Hemizygous, interstitial deletion of chromosome 5q is the most common cytogenetic abnormality in myelodysplastic syndrome (MDS) and has been the focus of functional analysis. Some patients with this molecular lesion have the 5q- syndrome, a disorder with a highly consistent clinical phenotype. A systematic RNA interference screen to interrogate the function of each gene in the common deleted region (CDR) for the 5q- syndrome identified RPS14 as a critical haploinsufficiency disease gene for the erythroid failure, which is a characteristic of this syndrome. Genes located in an adjacent deleted region have also been implicated in MDS. The full clinical phenotype is likely caused by the integration of effects from allelic insufficiency for multiple genes. With the identification and characterization of these genes, the 5q deletion is becoming a model for understanding hemizygous chromosomal deletions in cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Chromosome Deletion*
  • Chromosomes, Human, Pair 5*
  • Humans
  • Myelodysplastic Syndromes / genetics*
  • RNA Interference