An uncommon presentation of autoimmune polyglandular syndrome type 1 (APS-1)-A case report.

Key Clinical Message: Autoimmune polyglandular syndrome type 1 (APS-1) is a rare disorder defined by the presence of at least two of the following conditions: chronic mucocutaneous candidiasis (CMC), chronic hypoparathyroidism, and Addison's syndrome. Despite the lack of CMC and autoimmune history, APS-1 can be diagnosed using genetic testing. We present the case of a 28-year-old female patient with a history of hypocalcemia due to hypoparathyroidism since the age of 2 years. She presented to the endocrine clinic with hypogonadism, primary amenorrhea, and primary ovarian insufficiency. Addison's disease was eventually diagnosed, despite a negative Synacthen test. The adrenal crisis required intravenous hydrocortisone therapy. No CMC was documented, and there was no family history of such conditions. The diagnosis of APS-1 was confirmed by genetic testing, revealing homozygous pathogenic variants of the autoimmune regulator gene. Management included oral calcium and calcitriol and oral hydrocortisone and fludrocortisone for Addison's disease. Hormonal induction of secondary sexual characteristics was initiated. The patient received combined oral estrogen and progesterone pills. This case highlights the critical significance of early recognition, thorough evaluation, and tailored treatment for patients with APS-1 to enhance their quality of life and mitigate potentially life-threatening complications. This underscores the importance of screening for associated minor autoimmune diseases as part of a holistic approach to care.