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IPEX, an X-linked syndrome (Immune dysregulation, Polyendocrinopahy, Enteropathy and X-linked syndrome) is a rare disorder occurring in boys. It is characterized by intractable diarrhea, ichthyosiform dermatitis, early-onset insulin-dependent diabetes mellitus, thyroiditis, hemolytic anemia, variable autoimmune phenomena and severe infections. In the seven kindreds studied so far, transmission of the disease was X-linked and recessive. However, sporadic cases in boys have also been reported. Prognosis is poor. Supportive therapy with total parenteral nutrition, insulin and blood transfusions is beneficial. Allogenic bone marrow transplantation from an HLA-identical person might be a curative option, even though long-term complications, such as hemophagocytosis may occur. The IPEX gene has been mapped to chromosome Xp11.23-Xq13.3 and encodes a putative DNA-binding protein, FOXP3. This protein has significant homology to forkhead/winged-helix transcription factor family. Most mutations of FOXP3 are localized in the carboxyl-terminal forkhead DNA binding domain, suggesting a critical role for this domain in FOXP3 function. The diagnosis could be made prenatally from chorionic villous samples. |