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X-chromosome Inactivation and Disease

  1. Mary F Lyon

Published Online: 16 JUL 2007

DOI: 10.1002/9780470015902.a0005480.pub2



How to Cite

Lyon, M. F. 2007. X-chromosome Inactivation and Disease. eLS. .

Author Information

  1. Medical Research Council Mammalian Genetics Unit, Harwell, UK

Publication History

  1. Published Online: 16 JUL 2007


X-chromosome inactivation is the phenomenon in which one of the two X chromosomes in every somatic cell of female mammals becomes transcriptionally inactive early in embryonic development. This has the result of equalizing the effective gene dosage of X-linked genes in chromosomally XX females and XY males, and is hence known as a dosage-compensation mechanism. In humans, X-chromosome inactivation has implications for the effects seen in diseases due either to X-linked genes or to numerical or structural anomalies of the X-chromosome.


  • X-linked diseases;
  • X-chromosome aneuploidy;
  • X-autosome translocations;
  • XIST gene;
  • X-inactivation centre