Autoimmune polyendocrine syndrome type 1 (APS-1), also referred to as autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a rare monogenic disorder, is classically characterized by a triad of chronic mucocutaneous candidiasis, hypoparathyroidism, and primary adrenal insufficiency. The identified causative gene is autoimmune regulator (AIRE), which encodes a critical transcription factor and is essential for self-tolerance. Here, we describe a late-onset Chinese case who presented with symptoms of persistent tetany due to hypocalcemia. Extensive clinical evaluations revealed that the patient manifested beyond the classic triad of the disease, and next-generation sequencing identified a known homozygous AIRE mutation (p.R139X). APS-1 is a rare inherited immunodeficiency disease with high clinical and genetic heterogeneity. By retrospectively analyzing the disease, we comprehensively reviewed the phenotypic features, summarized the genotype spectrum, and discussed the possible immunological mechanisms of the disease to enhance earlier recognition and implement targeted preventive and therapeutic strategies.