National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Omenn syndrome


Other Names:
Reticuloendotheliosis familial with eosinophilia; Severe combined immunodeficiency with hypereosinophilia
Categories:
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.[1][2][3] 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.[1] Omenn syndrome has been found to be caused by mutations in the RAG1 or RAG2 genes.[1][3] Additional causative genes have been identified.[1] 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.[1][2]
Last updated: 3/21/2012
Infants with Omenn syndrome typically present shortly after birth, usually by 3 months of age. This is similar to other types of severe combined immunodeficiency (SCID). The characteristic skin findings (red and peeling skin), chronic diarrhea, and failure to thrive often precede the onset of infections. Life-threatening infections caused by common viral, bacterial, and fungal pathogens occur next. Lymphadenopathy and hepatosplenomegaly, both symptoms unique to Omenn syndrome, develop next.[1]
Last updated: 3/21/2012

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal lymphocyte morphology 0004332
Alopecia
Hair loss
0001596
Chronic diarrhea 0002028
Erythroderma 0001019
Failure to thrive
Faltering weight
Weight faltering
[ more ] 		0001508
Hepatomegaly
Enlarged liver
0002240
Lymphadenopathy
Swollen lymph nodes
0002716
Severe combined immunodeficiency 0004430
30%-79% of people have these symptoms
Aplasia/Hypoplasia of the eyebrow
Absence of eyebrow
Lack of eyebrow
Missing eyebrow
[ more ] 		0100840
Desquamation of skin soon after birth 0007549
Dry skin 0000958
Edema
Fluid retention
Water retention
[ more ] 		0000969
Eosinophilia
High blood eosinophil count
0001880
Fever 0001945
Pneumonia 0002090
Pruritus
Itching
Itchy skin
Skin itching
[ more ] 		0000989
Splenomegaly
Increased spleen size
0001744
Thickened skin
Thick skin
0001072
5%-29% of people have these symptoms
Abnormality of the metaphysis
Abnormality of the wide portion of a long bone
0000944
Anemia
Low number of red blood cells or hemoglobin
0001903
Autoimmunity
Autoimmune disease
Autoimmune disorder
[ more ] 		0002960
Hypothyroidism
Underactive thyroid
0000821
Lymphoma
Cancer of lymphatic system
0002665
Nephrotic syndrome 0000100
Sepsis
Infection in blood stream
0100806
Short toe
Short toes
Stubby toes
[ more ] 		0001831
Thyroiditis
Thyroid gland inflammation
0100646
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance 0000007
Diarrhea
Watery stool
0002014
Hypoplasia of the thymus
Small thymus
0000778
Hypoproteinemia
Decreased protein levels in blood
0003075
Recurrent bacterial infections
Bacterial infections, recurrent
Frequent bacterial infections
Increased susceptibility to bacterial infections
Recurrent major bacterial infections
[ more ] 		0002718
Recurrent fungal infections 0002841
Recurrent viral infections 0004429
Severe B lymphocytopenia 0005365
Thrombocytopenia
Low platelet count
0001873
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Last updated: 7/1/2020
Omenn syndrome is a genetically heterogeneous condition (meaning that it may be caused by a number of different genes). While most cases are attributed to mutations in the RAG genes (RAG-1 and RAG2 genes have been mapped to chromosome band 11p13), recent reports describe Omenn syndrome in the absence of RAG mutations.[1][3] Omenn syndrome caused by mutations in ARTEMIS, ADA, ILRA2, ILRA7, CHD7, and DNA ligase 4 have been described in the medical literature. Some cases of Omenn syndrome have also been found in association with 22q11 microdeletion syndrome.[1]
Last updated: 3/21/2012
The standard treatment for Omenn syndrome is bone marrow transplantation or cord blood stem cell transplantation.[1][2] General care for any patient with severe combined immunodeficiency (SCID), including Omenn syndrome, includes isolation to prevent infection and meticulous skin and mucosal hygienic practices while the patient is awaiting stem cell reconstitution. Broad-spectrum antibiotics may be administered parenterally while cultures and body fluid analyses are in progress. Parenteral nutrition may also be provided as therapy for diarrhea and failure to thrive.[1] A detailed description of therapeutic options is provided in the referenced eMedicine article.
Last updated: 3/21/2012

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnoses include graft-versus-host disease, histiocytosis, Job syndrome, Netherton syndrome, and severe combined immunodeficiencies (see these terms), particularly those associated with maternal T-cell engraftment.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Omenn syndrome. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry

  • A registry supports research by collecting of information about patients that share something in common, such as being diagnosed with Omenn syndrome. The type of data collected can vary from registry to registry and is based on the goals and purpose of that registry. Some registries collect contact information while others collect more detailed medical information. Learn more about registries.

    Registries for Omenn syndrome:
    European Society for Immunodeficiencies (ESID) Registry
    United States Immunodeficiency Network (USIDENT) Registry
     
  • The Primary Immune Deficiency Treatment Consortium (PIDTC) is a team of doctors, nurses, research coordinators, and research labs throughout the U.S., working together to improve the lives of people with severe combined immunodeficiency, Wiskott-Aldrich syndrome, and chronic granulomatous disease through research. The Primary Immune Deficiency Treatment Consortium (PIDTC) has a registry for patients who wish to be contacted about clinical research opportunities.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Omenn syndrome. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • I am the oldest person alive with Omenn Syndrome.  I don't know much about it except what my grandmother has told me.  She told me that it is an immune deficiency.  Can you tell me more about it? See answer


  1. Schwartz RA, Lin RY. Omenn Syndrome. eMedicine. May 9, 2011; http://emedicine.medscape.com/article/887687-overview. Accessed 3/21/2012.
  2. Aleman K, Noordzij JG, de Groot R, van Dongen JJ, Hartwig NG. Reviewing Omenn syndrome. Eur J Pediatr. 2001; http://www.ncbi.nlm.nih.gov/pubmed/11795679. Accessed 3/21/2012.
  3. Zhang ZY, Ahao XD, Jiang LP, Liu EM, Cui YX, Wang M, Wei H, Yu J, An YF, Yang XQ. Clinical characteristics and molecular analysis of three Chinese children with Omenn syndrome. Pediatr Allergy Immunol. 2011; http://www.ncbi.nlm.nih.gov/pubmed/21771083. Accessed 3/21/2012.