MedlinePlus Genetics :
43
Omenn syndrome is an inherited disorder of the immune system (immunodeficiency). Omenn syndrome is one of several forms of severe combined immunodeficiency (SCID), a group of disorders that cause individuals to have virtually no immune protection from bacteria, viruses, and fungi. Individuals with SCID are prone to repeated and persistent infections that can be very serious or life-threatening. Infants with Omenn syndrome typically experience pneumonia and chronic diarrhea. Often the organisms that cause infection in people with this disorder are described as opportunistic because they ordinarily do not cause illness in healthy people.In addition to immunodeficiency, children with Omenn syndrome develop autoimmunity, in which the immune system attacks the body's own tissues and organs. This abnormal immune reaction can cause very red skin (erythroderma), hair loss (alopecia), and an enlarged liver and spleen (hepatosplenomegaly). In addition, affected individuals have enlargement of tissues that produce infection-fighting white blood cells called lymphocytes. These include the thymus, which is a gland located behind the breastbone, and lymph nodes, which are found throughout the body.If not treated in a way that restores immune function, children with Omenn syndrome usually survive only until age 1 or 2.
MalaCards based summary :
Omenn Syndrome, also known as
histiocytic medullary reticulosis, is related to
combined immunodeficiency and
hypereosinophilic syndrome, and has symptoms including
diarrhea An important gene associated with Omenn Syndrome is
RAG2 (Recombination Activating 2), and among its related pathways/superpathways are
Innate Immune System and
TGF-Beta Pathway. Affiliated tissues include
t cells,
b cells and
bone marrow, and related phenotypes are
failure to thrive and
hepatomegaly
Disease Ontology :
12
A severe combined immunodeficiency that has material basis in the RAG1 and RAG2 genes on chromosome 11p and the Artemis gene on chromosome 10p. It is characterized by erythroderma, desquamation, alopecia, chronic diarrhea, failure to thrive, lymphadenopathy, and hepatosplenomegaly.
GARD :
20
Omenn syndrome is an autosomal recessive form of severe combined immunodeficiency (SCID) characterized by erythroderma (skin redness), desquamation (peeling skin), alopecia (hair loss), chronic diarrhea, failure to thrive, lymphadenopathy (enlarged lymph nodes), eosinophilia, hepatosplenomegaly, and elevated serum IgE levels. Patients are highly susceptible to infection and develop fungal, bacterial, and viral infections typical of SCID. In this syndrome, the SCID is associated with low IgG, IgA, and IgM and the virtual absence of B cells. There is an elevated number of T cells, but their function is impaired. Omenn syndrome has been found to be caused by mutations in the RAG1 or RAG2 genes. Additional causative genes have been identified. Early recognition of this condition is important for genetic counseling and early treatment. If left untreated, Omenn syndrome is fatal. The prognosis may be improved with early diagnosis and treatment with compatible bone marrow or cord blood stem cell transplantation.
OMIM® :
57
Omenn syndrome is an autosomal recessive disorder characterized by severe combined immunodeficiency (SCID) associated with erythrodermia, hepatosplenomegaly, lymphadenopathy, and alopecia. 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 (summary by Ege et al., 2005).
(603554) (Updated 05-Mar-2021)
UniProtKB/Swiss-Prot :
73
Omenn syndrome: Severe immunodeficiency characterized by the presence of activated, anergic, oligoclonal T-cells, hypereosinophilia, and high IgE levels.
Wikipedia :
74
Omenn syndrome is an autosomal recessive severe combined immunodeficiency. It is associated with...
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Rare immunological diseases 
