Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019214 (hepatosplenomegaly)
 4,408 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Omenn syndrome (OS) is characterized by severe combined immunodeficiency (SCID) associated with erythrodermia, hepatosplenomegaly, lymphadenopathy, and alopecia. In patients with OS, B cells are mostly absent, T-cell counts are normal to elevated, and T cells are frequently activated and express a restricted T-cell receptor (TCR) repertoire. Thus far, inherited hypomorphic mutations of the recombination activating genes 1 and 2 (RAG1/2) have been described in OS. We report on a first patient with clinical and immunologic features of OS caused by hypomorphic ARTEMIS mutations. The patient's T cells expressed alpha/beta receptors with an oligoclonal repertoire but normal V(D)J recombination coding joints. Sequencing of the ARTEMIS gene revealed a compound heterozygosity in this nonhomologous end-joining (NHEJ) factor, explaining the enhanced radiosensitivity of the patient's primary dermal fibroblasts. The maternal allele contained a null mutation within the active center, whereas the expression of the paternal allele with a start codon (AUG to ACG) mutation partially restored V(D)J recombination and ARTEMIS function in vivo and in vitro.
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PMID:Omenn syndrome due to ARTEMIS mutations. 1573 Nov 74

Omenn syndrome (OS) is a rare disorder within the combined immunodeficiency family that is characterized by a diffuse exudative, erythematous rash, lymphadenopathy, hepatosplenomegaly, alopecia, and failure to thrive. Specific lab findings unique to OS include hypereosinophilia, elevated IgE, excess production of oligoclonal T-cells and near-to-absent B-cells. Much remains elucidated about the underlying genetic cause of OS. Until recently, it was felt that the disease was primarily caused by mutations of the RAG1 or RAG2 genes. The type of mutation of the RAG1 and RAG2 genes in patients with OS affects the degree of functioning variable (diversity) joining [V(D)J] recombination activity, which is critical to the development of lymphoid cell receptor diversity. New work has also shown that thymic tissue in OS patients demonstrates a severe defect in the expression of the autoimmune regulator element. This may contribute to the development of autoreactive T-cells that are felt to be the causative agent of a number of the clinical hallmarks unique to OS. The genetic spectrum of OS was further expanded when a patient with clinical and immunologic features consistent with OS, without RAG mutation, was found to have mutations in both alleles coding for ARTEMIS, a key V(D)J recombination/DNA repair factor. Regardless of the underlying cause, early recognition is critical because patients die at a very young age without bone marrow transplantation. We describe an infant diagnosed with OS post-mortem in which death was directly related to the development of necrotizing enterocolitis.
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PMID:Necrotizing enterocolitis in an infant with Omenn syndrome. 1717 92

Omenn syndrome is a form of severe combined immunodeficiency associated with erythrodermia, hepatosplenomegaly, lymphadenopathy, and alopecia. Inherited hypomorphic mutations in the recombination activating genes 1 and 2 (RAG1 and RAG2) and in ARTEMIS genes and more recently defects in IL7RA, and RMRP genes have been described to be responsible of this peculiar immunodeficiency. The authors report here a Moroccan patient of four-months-old with classical features of Omenn syndrome, carrying a deletion at the N terminal part of RAG1. Early recognition of this condition is important for genetic counseling and early treatment.
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PMID:Omenn syndrome with mutation in RAG1 gene. 1901 8

Primary immunodeficiencies are genetic disorders in which components of immunological pathways are either missing or dysregulated. With the advent of next-generation sequencing, testing for genes in conditions with a heterogeneous genetic background seems more promising. We designed a custom microarray with 385K probe capacity to capture exons of 395 human genes, known or predicted to be associated with primary immunodeficiency and immune regulation. Enriched target DNA was sequenced using a GS FLX Titanium 454 platform. The patients selected were likely to have an underlying immunodeficiency. In one patient with hepatosplenomegaly, recurrent infections and an elevated IgM level, sequence analysis of the patient and his two unaffected parents identified ATM (ataxia telangiectasia mutated) as the underlying defect. In a second child with a clinical SCID phenotype, we detected a mutation in the ARTEMIS gene after focusing on SCID-associated genes. 454 sequencing yielded 152,000-397,000 high-quality reads per patient. 78-99% of the targeted nucleotides were covered at least one time, 76-82% at least five times. Array-based sequence capture expands our capacities to sequence large targeted DNA regions in a less laborious and time-consuming approach. Our array was capable to find the underlying genetic defect in two patients with suspected primary immunodeficiency. Upcoming whole-exome sequencing definitely will add more valuable data, but bioinformatical analysis and validation of variants already pose major challenges.
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PMID:Array-based sequence capture and next-generation sequencing for the identification of primary immunodeficiencies. 2201 23