immunology allergic disorders
Hyper IgM Syndrome
Autosomal recessive hyper IgM syndrome
In autosomal recessive hyper-IgM syndrome with CD40 mutation, manifestations are similar to those of the X-linked form. At least 4 autosomal recessive forms involve a B-cell defect. In 2 of these forms (deficiency of activation-induced cytidine deaminase [AID] or uracil DNA glycosylase [UNG]), serum IgM levels are much higher than in the X-linked form; lymphoid hyperplasia (including lymphadenopathy, splenomegaly, and tonsillar hypertrophy) is present, and autoimmune disorders may be present. Leukopenia is absent. 