1. Case of a 10-Year-Old Boy with Hyper–Immunoglobulin M Immunodeficiency Caused by Activation-Induced Cytidine Deaminase Deficiency
- Author
-
Elena Lewis and Russell J. Hopp
- Subjects
Pulmonary and Respiratory Medicine ,biology ,business.industry ,Point mutation ,Cytidine deaminase ,medicine.disease ,Immunoglobulin E ,Virology ,Immunoglobulin class switching ,Immunoglobulin M ,Pediatrics, Perinatology and Child Health ,Immunology ,medicine ,biology.protein ,Activation-induced (cytidine) deaminase ,Immunology and Allergy ,Missense mutation ,business ,Immunodeficiency - Abstract
We report the case of a 10-year-old boy, with a history of recurrent sinopulmonary infections, presenting with pneumococcal meningitis. Immune workup found low immunoglobulin G (IgG), IgA, and IgE and elevated IgM. Specific antibodies to pneumococcus, tetanus, and mumps were low. Genetic testing identified CD40L and uracil-DNA glycosylase as normal. Sequence analysis for mutations in activation-induced cytidine deaminase (AID) gene on chromosome 12p13 revealed a single missense mutation in exon 3 caused by a point mutation. AID is an enzyme that is specifically present in activated B cells and necessary for isotype switching. This case highlights the significance of AID deficiency in hyper-IgM immunodeficiency.
- Published
- 2010
- Full Text
- View/download PDF