IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked) syndrome is characterized by systemic autoimmunity, typically beginning in the first year of life, which includes the triad of enteropathy (manifesting as malabsorption and watery diarrhea), endocrinopathy (most commonly type 1 insulin-dependent diabetes mellitus), and eczematous dermatitis. In addition to these manifestations, many children have other autoimmune phenomena including cytopenias, autoimmune hepatitis, nephropathy, lymphadenopathy, splenomegaly, alopecia, arthritis, and interstitial lung disease related to immune dysregulation. Fetal presentation of IPEX syndrome includes hydrops, echogenic bowel, skin desquamation, intrauterine growth deficiency, and fetal akinesia. Without aggressive immunosuppression or hematopoietic stem cell transplantation (HSCT), the majority of affected males will die within the first one to two years of life from metabolic derangements, severe malabsorption, or sepsis. Individuals with a milder phenotype have survived into the second or third decade of life, but this is uncommon.