IPEX is caused by mutations in the gene FOXP3, which encodes transcription factor forkhead box P3 (FOXP3). FOXP3 is widely considered to be the master regulator of the regulatory T cell (Treg) lineage.[6][7]FOXP3 mutation can lead to the dysfunction of CD4+ Tregs. In healthy people, Tregs maintain immune homeostasis.[8] When there is a deleterious FOXP3 mutation, Tregs do not function properly and cause autoimmunity.[8][9]
IPEX onset usually happens in infancy. If left untreated, it is often fatal by the age of 2 or 3.[10][11] A bone marrow transplant is generally considered the best treatment option.[11] IPEX exclusively affects males and is inherited in an X-linked recessive manner;[1][2] female carriers of pathogenic FOXP3 mutations do not have symptoms and no female cases are known.[4]
^ abHannibal M, Torgerson T (1993-01-01). "IPEX Syndrome". In RA, Adam MP, Ardinger HH, Wallace SE, Amemiya A, Bean LJ, Bird TD, Ledbetter N, Mefford H (eds.). GeneReviews. Seattle (WA): University of Washington, Seattle. PMID20301297.update 2011