IL1RN Gene

The IL1RN gene (IL1RN stands for: Interleukin 1 Receptor Antagonist) is a protein-coding gene located on chromosome 2q14.1.

The protein encoded by the IL1RN gene, interleukin 1 receptor antagonist, is a member of the interleukin-1 cytokine family. The interleukin-1 receptor antagonist inhibits the activity of interleukin-1 by binding to its receptor(IL1R1) and thus preventing its association with the co-receptor IL1RAP for signal transmission. The interleukin-1 receptor antagonist thus inhibits the activities of interleukin-1alpha (IL-1alpha) and interleukin-1beta (IL-1beta) and modulates a variety of interleukin-1-related immune and inflammatory responses, particularly in the acute phase of infection and inflammation. Several alternatively spliced transcript variants encoding different isoforms are known.

The IL1RN gene and five other closely related cytokine genes form a gene cluster that spans approximately 400 kb on chromosome 2. A polymorphism of this gene has been reported to be associated with an increased risk of osteoporotic fractures and gastric cancer.

Diseases associated with IL1RN include:

• DIRA (Osteomyelitis, Sterile Multifocal, With Periostitis And Pustulosis; Note: Relationships to AGEP ).

The encoded protein binds to the functional interleukin-1 receptor IL1R1 with greater affinity than to the decoy receptor IL1R2; however, the physiological significance of IL1R2 binding is unclear.

1. Aksentijevich I et al (2009) An autoinflammatory disease with deficiency of the interleukin-1 receptor antagonist. New Eng J Med 360: 2426-2437.
2. Ivker RA et al (1993) Infantile generalized pustular psoriasis associated with lytic lesions of the bone. Pediat Derm 10: 277-282.
3. Leung VC et al (1985) Infantile cortical hyperostosis with intramedullary lesions. J Pediat Orthop 5354-5357.
4. Reddy S et al (2009) An autoinflammatory disease due to homozygous deletion of the IL1RN locus. New Eng J Med 360: 2438-2444.
5. Sofman MS et al (1990) Dermatoses associated with sterile lytic bone lesions. J Am Acad Derm 23: 494-498.