With no history of neck surgery, renal disease, autoimmune disease, or malabsorption, a diagnosis of idiopathic hypoparathyroidism was supported, likely unmasked by denosumab-associated suppression of bone resorption. Denosumab treatment was withheld, and calcium carbonate and calcitriol supplementation led to stabilization of serum calcium in the low-normal range, but PTH levels remained suppressed. The gene discussed is PTH; the disease is autoimmune disease.