Refractory hypoparathyroidism in paediatric autoimmune polyglandular syndrome type 1: successful long-term use of teriparatide.

Autoimmune polyglandular syndrome type 1 (APS-1) is a rare monogenic disorder caused by pathogenic variants in the autoimmune regulator (AIRE) gene. It typically manifests in childhood with at least two features of the classic triad: chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency. We present the case of an 11-year-old girl from a consanguineous family, with severe hypocalcaemia and chronic oral candidiasis. Despite high-dose calcium and calcitriol therapy, she experienced recurrent symptomatic hypocalcaemia requiring multiple hospitalisations. Genetic testing confirmed homozygosity for the pathogenic AIRE variant c.967_979del, establishing the diagnosis of APS-1. Due to poor biochemical control, teriparatide (parathyroid hormone, PTH [1-34]) was initiated at 20 g twice daily, leading to rapid improvement in calcium-phosphate homeostasis, a 75% reduction in oral calcium requirements, and no further hospitalisations over a two-year period. The therapy was well tolerated with no adverse events. This is the first paediatric case reported in Colombia using recombinant PTH (1-34) for APS-1-related hypoparathyroidism, supporting its therapeutic role in refractory cases.