Various serum immunoglobulin abnormalities were detected including hypogammaglobulinemia (n = 55, 23.7%), hypergammaglobulinemia (n = 30, 12.9%), hyper-IgE (n = 28, 12.1%), dysgammaglobulinemia (n = 26, 11.2%), agammaglobulinemia (n = 18, 7.8%), specific antibody deficiency (n = 7, 3%), IgG subclass deficiency (n = 6, 2.6%), IgA deficiency (n = 2, 0.9%), and hyper-IgM (n = 2, 0.9%). The gene discussed is CD40LG; the disease is selective IgA deficiency disease.