DiGeorge infants who have successful thymus transplants but remain with hypoparathyroidism must go to the clinic for frequent calcium levels and to the hospital for calcium infusions; these infants are at risk for seizures from low calcium. Approximately ½ of infants with profound hypoparathyroidism will develop nephrocalcinosis. This protocol had a parental parathyroid transplant arm for complete DiGeorge infants with athymia and profound hypoparathyroidism.