Autoimmune lymphoproliferative syndrome with somatic Fas mutations

N Engl J Med. 2004 Sep 30;351(14):1409-18. doi: 10.1056/NEJMoa040036.


Background: Impaired Fas-induced apoptosis of lymphocytes in vitro is a principal feature of the autoimmune lymphoproliferative syndrome (ALPS). We studied six children with ALPS whose lymphocytes had normal sensitivity to Fas-induced apoptosis in vitro.

Methods: Susceptibility to Fas-mediated apoptosis and the Fas gene were analyzed in purified subgroups of T cells and other mononuclear cells from six patients with ALPS type III.

Results: Heterozygous dominant Fas mutations were detected in the polyclonal double-negative T cells from all six patients. In two patients, these mutations were found in a fraction of CD4+ and CD8+ T cells, monocytes, and CD34+ hematopoietic precursors, but not in hair or mucosal epithelial cells.

Conclusions: Somatic heterozygous mutations of Fas can cause a sporadic form of ALPS by allowing lymphoid precursors to resist the normal process of cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Apoptosis
  • Autoimmune Diseases / classification
  • Autoimmune Diseases / genetics*
  • Cells, Cultured
  • Child
  • DNA Mutational Analysis
  • Female
  • Gene Expression
  • Hematopoiesis / genetics
  • Hematopoiesis / physiology
  • Heterozygote
  • Humans
  • Lymphoproliferative Disorders / classification
  • Lymphoproliferative Disorders / genetics*
  • Male
  • Mosaicism
  • Mutation*
  • Phenotype
  • Polymerase Chain Reaction
  • Receptors, Antigen, T-Cell / genetics
  • Receptors, Antigen, T-Cell / immunology
  • T-Lymphocytes
  • fas Receptor / genetics*


  • Receptors, Antigen, T-Cell
  • fas Receptor