Immune Dysregulation, Polyendocrinopathy, Enteropathy, X-linked (IPEX) Syndrome
- Inheritance: X-linked recessive
- Gene: FOXP3
- Protein: FOXP3
- Tests: FOXP3 Gene Sequencing, FOXP3/CD25 Protein Flow/TREG Flow
Key Clinical and Laboratory Features
- Common clinical features: Typical triad is early-onset enteropathy (watery diarrhea, onset typically before 6 months of age), endocrinopathy (Type 1 diabetes or thyroiditis) and dermatitis (eczema, psoriasiform dermatitis, pemphigoid, etc.).
- Other clinical features: Autoimmune hemolytic anemia (AIHA), idiopathic thrombocytopenic purpura (ITP), autoimmune neutropenia, autoimmune hepatitis, autoimmune nephropathy, etc.
- Physical exam: Dermatitis (eczema) is common. Sometimes lymphadenopathy and splenomegaly are present.
- Common laboratory features: Highly elevated IgE in almost all patients. Other immunoglobulin subsets are typically normal. Eosinophilia is common. Markedly decreased or absent FOXP3+ regulatory T cells.
|GENE||FOXP3 Gene Sequencing||The gold standard for confirming a diagnosis of IPEX in a patient with suggestive symptoms.|
|PROTEIN||FOXP3/CD25 Protein Flow/TREGFlow||FOXP3 expressing regulatory T cells are absent or markedly decreased in more than 75% of patients with IPEX syndrome. There are however some patients with missense mutations in FOXP3 that express near-normal levels of FOXP3 protein. This test does not provide any information about the regulatory function of the FOXP3 expressing cells.|
|FUNCTION||N/A||There are currently no available clinical tests to evaluate FOXP3 protein function.|