Forkhead box P3 (FOXP3) is the gene responsible for IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked).
FOXP3 is located on the X chromosome and is of crucial importance for the generation of CD4+ CD25+ regulatory T cells.
Loss of FOXP3 function and the resultant lack of regulatory T cells result in lethal auto-aggressive lymphoproliferation, whereas overexpression of this modulator results in severe immunodeficiency.
mutation in IPEX syndrome (Immunodysregulation, Polyendocrinopathy, Enteropathy, X-linked) (MIM.304790)
References
Ochs HD, Ziegler SF, Torgerson TR. FOXP3 acts as a rheostat of the immune response. Immunol Rev. 2005 Feb;203:156-64. PMID: #15661028#