The diagnosis of a parathyroid mass was suspected by the analytical finding of PHPT (hypercalcemia and elevated PTH) and later confirmed by ultrasound (non-invasive and low-cost procedure) and 99mTc-Sestamibi scintigraphy (sensitivity of 90% in detecting parathyroid adenomas) [5,9]. The gene discussed is PTH; the disease is parathyroid gland adenoma.