Asymptomatic neonatal familial hypercalcemia

Although rare, primary hyperparathyroidism in infancy has been characterized as a universally severe, potentially lethal disorder. In the 18 reported cases, the clinical presentation has been one of moderate to severe hypercalcemia and failure to thrive, with anorexia, hypotonia, constipation, and bone disease. Nine of the eighteen cases resulted in death. No untreated infants have survived. Several authors have stressed the fatal outcome of untreated infantile hyperparathyroidism and have recommended early parathryroidectomy. In marked contrast to previous descriptions of infantile hyperparathyroidism, we report hypercalcemia in a neonatal member of a kindred with familial hypercalcemia. In this infant hypercalcemia has thus far been unassociated with any apparent impairment of growth or development.