Clinical and immunologic spectrum of the DiGeorge syndrome.

This report summarizes the spectrum of clinical and immunologic findings gathered prospectively in 13 patients with the DiGeorge syndrome. Our patients demonstrated marked variability in both the clinical manifestations and the degree of immunodeficiency, confirming the findings of earlier individual case reports and retrospective autopsy reviews. Ages at the time of presentation ranged from one day to 4 months. Congenital heart defects including truncus arteriosus, ventricular septal defect, interrupted aortic arch, and tetralogy of Fallot commonly brought these infants to medical attention within the first two weeks of life. Abnormal calcium homeostasis was found in all patients. Those patients presenting after the first month of life often had hypocalcemic seizures as the initial clinical manifestation. Parathyroid hormone levels and the number and location of parathyroid glands varied considerably. Immunologic evaluation revealed that total lymphocyte counts, percent T-cells, total T-cells, and T-lymphocyte function ranged from normal to severely depressed. The most consistent immunologic abnormality, found in 11 of the 13 patients, was a decrease in total T-cells. Sequential studies in five patients demonstrate that spontaneous resolution of immunodeficiency may occur in some, yet progressive loss of immune function may be observed in others. Complete immunologic evaluation and careful followup is mandatory in infants with persistent hypocalcemia and congenital heart disease who are suspected to have DiGeorge syndrome.