Patients with the rare X-linked syndrome, immune dysregulation, polyendocrinopathy, enteropathy (IPEX) may present early in life with type I diabetes, hyperthyroidism, chronic enteropathy, villous atrophy, dermatitis, autoimmune hemolytic anemia, and antibody- induced neutropenia and thrombocytopenia. Of the reported families with IPEX, most affected boys died before the age of 3 years of malabsorbtion, failure to thrive, infections, or other complications. Characteristic findings at autopsy include lymphocytic infiltrates affecting the lungs, endocrine organs, such as pancreas and thyroid and skin, and increased lymphoid elements in lymph nodes and spleen. Although symptomatic therapy with immunosuppressive drugs provides some beneficial effects, the only curative treatment is hematopoietic stem cell transplantation.