Immune dysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance (IPEX), a syndrome of systemic autoimmunity caused by mutations of FOXP3, a critical regulator of T-cell homeostasis

Curr Opin Rheumatol. 2003 Jul;15(4):430-5. doi: 10.1097/00002281-200307000-00010.


Immune dysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance (IPEX) is one of a group of clinical syndromes that present with multisystem autoimmune disease suggesting a phenotype of immune dysregulation. Clinically, IPEX manifests most commonly with diarrhea, insulin-dependent diabetes mellitus, thyroid disorders, and eczema. FOXP3, the gene responsible for IPEX, maps to chromosome Xp11.23-Xq13.3 and encodes a putative DNA-binding protein of the forkhead family. Recent data indicate that FOXP3 is expressed primarily in the CD4+CD25+ regulatory T-cell subset, where it may function as a transcriptional repressor and key modulator of regulatory T-cell fate and function. This review describes the clinical features of IPEX and the structure, function, and known mutations of FOXP3 that provide important insights into its role in maintenance of immune homeostasis.

Publication types

  • Review

MeSH terms

  • Animals
  • DNA-Binding Proteins / genetics*
  • Forkhead Transcription Factors
  • Genetic Diseases, X-Linked / metabolism*
  • Homeostasis
  • Humans
  • Immune System / physiopathology*
  • Mice
  • Mutation
  • Polyendocrinopathies, Autoimmune / genetics*
  • Protein-Losing Enteropathies / genetics*
  • Syndrome
  • T-Lymphocytes / physiology*
  • X Chromosome / genetics


  • DNA-Binding Proteins
  • FOXP3 protein, human
  • Forkhead Transcription Factors
  • Foxp3 protein, mouse