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Chromosome 21

  1. Emilie Ait Yahya-Graison,
  2. Jean Maurice Delabar

Published Online: 16 JUL 2007

DOI: 10.1002/9780470015902.a0005830.pub2



How to Cite

Yahya-Graison, E. A. and Delabar, J. M. 2007. Chromosome 21. eLS. .

Author Information

  1. Universite Paris Diderot, Paris, France

Publication History

  1. Published Online: 16 JUL 2007


Human chromosome 21 is the smallest of the five acrocentric chromosomes and contains ∼1.4% of the genetic material in the genome. Although relatively gene-poor, it contains around 10 genes Mb–1, a ribosomal ribonucleic acid (rRNA) gene cluster and three keratin-associated protein clusters.


  • chromosome 21;
  • sequencing;
  • Down syndrome;
  • Alzheimer disease;
  • leukaemia