Laboratory investigations revealed significant hypercalcemia (ionized calcium 1.69 mmol/L, total calcium unadjusted for albumin 3.44 mmol/L, 13.8 mg/dl), suppressed PTH (<1 pmol/L) and 1,25-dihydroxyvitamin D (<12 pmol/L) and PTH-related peptide was not high (0.9 pmol/L). The gene discussed is PTH; the disease is Hypercalcemia.