Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features ++ Congenital heart defects Hypocalcemia and seizures Distinctive craniofacial features Thymic hypoplasia Incidence is about 1:4000 births Associated immunodeficiency is secondary to the aplastic or hypoplastic thymus Most patients have no or only mild immune defects The term partial DiGeorge syndrome is commonly applied to patients with impaired rather than absent thymic function +++ Clinical Findings ++ Clinical characteristics include congenital heart defects, hypocalcemia due to hypoparathyroidism, distinctive craniofacial features, renal anomalies, and thymic hypoplasia Presentation usually results from cardiac failure or from hypocalcemia 24–48 hours postpartum Infections commonly present as recurrent ear-nose-throat infections Additional important clinical issues include delayed speech, cognitive impairment, and behavioral problems Risk of developing schizophrenia and autoimmune disorders in increased in these patients +++ Diagnosis ++ Laboratory evaluation typically reveals normal to decreased numbers of T lymphocytes with preserved T-lymphocyte function and normal B-lymphocyte function In the rare patient with absent or dysfunctional T lymphocytes, B-lymphocyte function and antibody production may be abnormal Over time, T-lymphocyte numbers normalize in the majority of patients who have low numbers of T lymphocytes at initial presentation Fluorescence in situ hybridization (FISH) chromosomal analysis for the microdeletion on chromosome 22, or microarray-based comparative genomic hybridization confirms diagnosis +++ Treatment ++ Surgery may be required for cardiac defects Vitamin D, calcium, or parathyroid hormone replacement to correct hypocalcemia and treat seizures may be needed Transfusion products should be irradiated Both thymic grafts and BMT have been used successfully in patients with absent T-lymphocyte immunity T-cell numbers and function should be assessed before administration of vaccine to avoid side effects Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth