Omenn syndrome

Omenn syndrome is an autosomal recessive severe combined immunodeficiency^[1] associated with mutations in the recombination activating genes (RAG1 and RAG2), affecting circulating levels of both B-cells and T-cells.

Symptoms

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.

Symptoms include:

• Desquamation (shedding the outer layers of skin)
• Chronic diarrhea
• Erythroderma (widespread reddening of the skin)
• Hepatosplenomegaly (simultaneous enlargement of both the liver and the spleen)
• Leukocytosis (elevation of the white blood cell count)
• Lymphadenopathy (swelling of one or more lymph nodes)
• Persistent bacterial infections
• Elevated serum IgE

Genetics

Treatment

Omenn syndrome is sometimes treated with bone marrow transplantation and cord blood stem cells.

See also

• Purine nucleoside phosphorylase deficiency
• List of cutaneous conditions

References