A 6-year-old girl has chronic mucocutaneous candidiasis, hypoparathyroidism with tetany, and primary adrenal insufficiency. Her elder sister has the same triad. Studies show reduced thymic deletion of self-reactive T cells specific for these endocrine antigens. The gene whose product controls thymic expression of tissue-specific self-antigens is:
- A AIRE ✓
- B FOXP3
- C CIITA
- D STAT3
Correct answer: A. AIRE
Explanation
Autoimmune polyendocrine syndrome type 1 results from autosomal recessive AIRE mutations. AIRE drives ectopic expression of tissue-specific antigens by medullary thymic epithelial cells, enabling negative selection of autoreactive T cells; its loss permits organ-specific autoimmunity affecting parathyroids, adrenals, and skin immunity to Candida. FOXP3 causes IPEX with immune dysregulation and enteropathy, CIITA mutations cause MHC class II deficiency, and STAT3 mutations cause hyper-IgE syndrome.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.