Immunologic Characteristics of CATCH 22 Syndrome

ABSTRACT

PURPOSE: Microdeletion of chromosome 22q11.2 are associated with DiGeorge syndrome(DGS), velocardiofacial syndrome(VCFS) and conotruncal anornaly face syndrome(CTAFS). DGS was originally described as an irnmunodeficiency disorder secondary to impaired T cell production due to thymic aplasia or hypoplasia. But the frequency E severity of immunodeficiency of other clinical syndromes associated with the chromosome 22qll deletion has not been investigated. This study was undertaken to investigate the frequency and severity of immunodeficiency, the relation- ship of the immunodeficiency to clinical phenotypes, and the change of immunologic status with age in CATCH 22 syndromes patients. METHODS: Sixteen patients with CATCH 22 syndrome with characteristic clinical phenotype and chromosome 22qll deletion were studied. Hurnoral and cellular irnmunities were examined by measuring serurn IgG, IgA, IgM level and by T cell subset through flow cytometry and lymphocyte proliferation test by common T cell mitogens respectively. RESULTS: 69Zo of patients with CATCH 22 syndrome were found to have evidence of immunocompromise. The severity of the immunodeficiency did not correlate with any particular phenotypic features nor was it restricted to patients who were categorized as having DiGeorge syndrome. The severity of immunodeficiency tended to be normalized with age. CONCLUSION: The presence of the immunocompromise is common and its severity cannot be predicted based on the clinical phenotype of CATCH 22 syndrome. Therefore, each child with CATCH 22 syndromes regardless of clinical phenotype should be extensively assessed for earlier detection of subclinical immunodeficiency.