Autoimmune polyglandular syndrome type 1 with compound heterozygous AIRE gene pathogenic variants and stage 1 type 1 diabetes mellitus: case report and literature review of Chinese population

Background: Autoimmune polyendocrine syndrome type 1 (APS-1) is a rare monogenic autoimmune disorder caused by pathogenic variants in the AIRE gene, characterized by impaired central immune tolerance and multi-organ autoimmune damage. While relatively common in genetically isolated populations, genetically confirmed APS-1 cases remain exceptionally rare in Chinese individuals. To date, population-specific genotypic and phenotypic features of APS-1 in China have not been systematically summarized. Case presentation: We report a 31-year-old female patient who presented with hypocalcemic convulsions as the initial symptom, accompanied by a 20-year history of vitiligo and mild anemia, newly developed chronic diarrhea and positive islet autoimmunity. Laboratory examinations confirmed hypoparathyroidism and stage 1 type 1 diabetes mellitus (T1DM) with significantly elevated islet autoantibodies but normal islet function. Genetic analysis identified novel compound heterozygous pathogenic variants in the AIRE gene: a missense variant c.977C>T (p.Pro326Leu) inherited from her mother and a 1.6 kb deletion spanning exons 2-4 with an untraceable origin due to the lack of paternal specimen, both classified as pathogenic according to ACMG guidelines. Conclusion: gene testing in young patients with non-surgical hypoparathyroidism and concurrent autoimmune manifestations to prevent misdiagnosis or delayed diagnosis.