Omenn syndrome
Overview
Omenn syndrome is an autosomal recessive severe combined immunodeficiency associated with mutations in the recombination activating genes (RAG1 and RAG2), affecting circulating levels of both B-cells and T-cells.
Symptoms
- Red rash
- Scaly rash
- Diffuse erythroderma
- Swollen lymph nodes
- Enlarged spleen
Causes
Villa et al. (1998) reported that patients with Omenn syndrome had missense mutations in either the RAG1 or the RAG2 gene that result in partial activity of the 2 proteins. Two of the amino acid substitutions mapped within the RAG1 homeodomain and decreased DNA-binding activity, whereas 3 others lowered the efficiency of RAG1/RAG2 interaction. The findings indicated that the immunodeficiency manifested in patients with Omenn syndrome arises from mutations that decrease the efficiency of V(D)J recombination.
Diagnosis
Diagnosis is generally made clinically because most SCID infants suffer recurrent overwhelming infections within 1 year of birth. Some infants are diagnosed after a severe reaction to vaccination. Defective humoral immunity is difficult to detect before age 5 months. Before then, even normal infants have very small amounts of serum immunoglobulin (Ig) M and IgA. Normal IgG levels merely reflect maternal IgG. Confirming diagnosis Severely diminished or absent T-cell number and function, as well as lymph node biopsy showing absence of lymphocytes, can confirm diagnosis of SCID.
Prognosis
The 'prognosis' of Omenn syndrome usually refers to the likely outcome of Omenn syndrome. The prognosis of Omenn syndrome may include the duration of Omenn syndrome, chances of complications of Omenn syndrome, probable outcomes, prospects for recovery, recovery period for Omenn syndrome, survival rates, death rates, and other outcome possibilities in the overall prognosis of Omenn syndrome. Naturally, such forecast issues are by their nature unpredictable.