V(D)J recombination defects in lymphocytes due toRAGmutations: severe immunodeficiency with a spectrum of clinical presentations

Autor: Villa, Anna, Sobacchi, Cristina, Notarangelo, Luigi D., Bozzi, Fabio, Abinun, Mario, Abrahamsen, Tore G., Arkwright, Peter D., Baniyash, Michal, Brooks, Edward G., Conley, Mary Ellen, Cortes, Patricia, Duse, Marzia, Fasth, Anders, Filipovich, Alexandra M., Infante, Anthony J., Jones, Alison, Mazzolari, Evelina, Muller, Susanna M., Pasic, Srdjan, Rechavi, Gideon, Sacco, Maria Grazia, Santagata, Sandro, Schroeder, Marlis L., Seger, Reinhard, Strina, Dario, Ugazio, Alberto, Väliaho, Jouni, Vihinen, Mauno, Vogler, Larry B., Ochs, Hans, Vezzoni, Paolo, Friedrich, Wilhelm, Schwarz, Klaus
Zdroj: Blood; January 2001, Vol. 97 Issue: 1 p81-88, 8p
Abstrakt: Severe combined immunodeficiency (SCID) comprises a heterogeneous group of primary immunodeficiencies, a proportion of which are due to mutations in either of the 2 recombination activating genes (RAG)-1 and -2, which mediate the process of V(D)J recombination leading to the assembly of antigen receptor genes. It is reported here that the clinical and immunologic phenotypes of patients bearing mutations in RAGs are more diverse than previously thought and that this variability is related, in part, to the specific type of RAGmutation. By analyzing 44 such patients from 41 families, the following conclusions were reached: (1) null mutations on both alleles lead to the T-B-SCID phenotype; (2) patients manifesting classic Omenn syndrome (OS) have missense mutations on at least one allele and maintain partial V(D)J recombination activity, which accounts for the generation of residual, oligoclonal T-lymphocytes; (3) in a third group of patients, findings were only partially compatible with OS, and these patients, who also carried at least one missense mutation, may be considered to have atypical SCID/OS; (4) patients with engraftment of maternal T cells as a complication of a transplacental transfusion represented a fourth group, and these patients, who often presented with a clinical phenotype mimicking OS, may be observed regardless of the type of RAGgene mutation. Analysis of the RAGgenes by direct sequencing is an effective way to provide accurate diagnosis of RAG-deficient as opposed toRAG-independent V(D)J recombination defects, a distinction that cannot be made based on clinical and immunologic phenotype alone.
Databáze: Supplemental Index