YIN-HSIU CHIENYAO-HSU YANGChu S.-Y.WUH-LIANG ​​HWUKuo P.-L.BOR-LUEN CHIANG2021-07-022021-07-0220020253-2662https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036746210&partnerID=40&md5=86e4658c358eb2ebe68af05ec52c3d77https://scholars.lib.ntu.edu.tw/handle/123456789/568049The most common immunodeficiency in DiGeorge sequence patients is defects in T-cell production due to insufficient thymic tissue. However, because T-lymphocytes are important in regulating antibody responses, DiGeorge sequence is no longer regarded as a pure deficiency of cellular immunity but also a form of variable-combined immunodeficiency. Here we presented a 4-month-old male infant with characteristic facial dysmorphism, thymus dysplasia, tetralogy of Fallot, and documented deletion of chromosome 22q11.2 who had decrease B-lymphocyte numbers and hypogammaglobulinemia. The mitogen responses of T-lymphocytes function were normal with adequate number of CD4+ lymphocytes. This case report highlights the importance of evaluating not only the cellular but also the humoral immune function in patients with DiGeorge sequence.[SDGs]SDG3article; case report; cellular immunity; chromosome 22q; chromosome deletion; combined immunodeficiency; DiGeorge syndrome; dysplasia; face dysmorphia; Fallot tetralogy; fluorescence in situ hybridization; human; humoral immunity; hypogammaglobulinemia; infant; male; syndrome delineation; thymus disease; Agammaglobulinemia; Antibody Formation; CD4 Lymphocyte Count; CD8-Positive T-Lymphocytes; Chromosomes, Human, Pair 22; DiGeorge Syndrome; Face; Fatal Outcome; Hemagglutinins; Humans; Immunity, Cellular; Immunoglobulins; In Situ Hybridization, Fluorescence; Infant; Lymphocyte Subsets; Malejournal article123807932-s2.0-0036746210