Characterization of immune function and analysis of RAG gene mutations in Omenn syndrome and related disorders
Autor: | Taizo Wada, Shoetsu Shimura, Kenkichi Takei, Akihiro Yachie, Yasushi Ishida, Shinsaku Imashuku, K Kawa-Ha, Shoichi Koizumi, Hidetoshi Seki, Yoshihito Kasahara, M Kudo |
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Jazyk: | angličtina |
Rok vydání: | 2000 |
Předmět: |
Male
Genes RAG-1 Immunology Mutation Missense Apoptosis Biology Gene mutation Compound heterozygosity Lymphocyte Activation Immunophenotyping RAG2 medicine Immunology and Allergy Missense mutation Immunodeficiency Humans VDJ Recombinases DNA Primers Genetics Recombinase activity Base Sequence Infant Newborn Infant Nuclear Proteins Gene rearrangement Syndrome medicine.disease Omenn syndrome DNA-Binding Proteins DNA Nucleotidyltransferases Cytokines Female Severe Combined Immunodeficiency Lymph Nodes |
Popis: | SUMMARY Omenn syndrome was recently found to be caused by missense mutations in RAG1 or RAG2 gene that result in partial V(D)J recombination activity. Although the clinical hallmarks of the disease are well defined, there have been several cases with clinical findings similar to, but distinct from Omenn syndrome. The data on immune functions and RAG gene mutations of such cases are limited. We described five Japanese infants from four unrelated families, including two cases of Omenn syndrome and three cases of related disorders. Sibling cases with typical Omenn phenotype were found to be compound heterozygotes of R396C and L885R mutations in RAG1. The former has been reported in European cases and may constitute a hot spot. The latter is a novel missense mutation. Infants with related disorders exhibited erythroderma, eosinophilia, hypogammaglobulinaemia, decreased number of B cells and skewing to Th2, and their lymph node specimens showed architectural effacement, lymphocyte depletion and histiocytic hyperplasia, each of which is seen characteristically in Omenn syndrome. However, in these cases serum IgE levels were low or undetectable. We found no mutation in RAG genes except for a K820R substitution in RAG1, which was regarded to be a functional polymorphism, in two of these cases. Our study suggests that RAG missense mutation may be a genetic abnormality unique to Omenn syndrome with characteristic clinical and laboratory findings. Variations of Omenn syndrome, or related disorders, may represent a different type of immunodeficiency, distinct from abnormalities in lymphoid-specific recombinase activity. |
Databáze: | OpenAIRE |
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