Omenn syndrome

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Omenn syndrome
Omenn syndrome has an autosomal recessive pattern of inheritance.
SpecialtyHematology Edit this on Wikidata

Omenn syndrome is an

ZAP-70 and complete DiGeorge syndrome
. It is fatal without treatment.

Symptoms and signs

Redness and scaliness of the entire skin on a 5-month-old female infant
A 5-month-old female infant with Omenn syndrome; she has red, scaly skin all over her body.

The symptoms are very similar to graft-versus-host disease (GVHD). This is because the patients have some T cells with limited levels of recombination with the mutant RAG genes. These T cells are abnormal and have a very specific affinity for self antigens found in the thymus and in the periphery. Therefore, these T cells are auto-reactive and cause the GVHD phenotype.[citation needed]

A characteristic symptom is chronic inflammation of the skin, which appears as a red rash

immunoglobulin levels (except immunoglobulin E, which is elevated), low T cell levels, and no B cells.[3]

Genetics

Omenn syndrome is caused by a partial loss of RAG gene function and leads to symptoms similar to

severe combined immunodeficiency syndrome, including opportunistic infections. The RAG genes are essential for gene recombination in the T-cell receptor and B-cell receptor, and loss of this ability means that the immune system has difficulty recognizing specific pathogens.[2] Omenn Syndrome is characterised by the loss of T-cell function, leading to engraftment of maternal lymphocytes in the foetus and the co-existence of clonally expanded autologous and transplacental-acquired maternal lymphocytes.[4]
Omenn syndrome can occasionally be caused in other recombination genes, including IL-7Rα and RMRP.[3]

Diagnosis

In order to diagnose a patient specifically with Omenn Syndrome, an autosomal recessive form of SCID, a physician can order a genetic testing panel to look for 22q11 microdeletions or mutations of the RAG1/RAG2 genes.[5]

Treatment

The only treatment for Omenn syndrome is

bone marrow transplantation.[3] Without treatment, it is rapidly fatal in infancy.[2]

See also

References

  1. S2CID 32270945
    .
  2. ^ .
  3. ^ .
  4. .
  5. ^ U.S. Department of Health and Human Services, National Institutes of Health, Genetic and Rare Diseases Information Center (last updated 2016). Omenn Syndrome. Retrieved from: https://rarediseases.info.nih.gov/diseases/8198/omenn-syndrome

External links