IL1RN

The L1RN gene (IL1RN stands for Interleukin 1 Receptor Antagonist) is a protein-coding gene located on chromosome 2q14.1.

The protein encoded by the L1RN gene is a member of the interleukin-1 cytokine family. The protein inhibits the activity of interleukin-1 by binding to the receptor IL1R1 and preventing its association with the co-receptor IL1RAP for signal transduction. The IL1RN 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. The protein thus inhibits the activities of interleukin-1, alpha (IL1A) and interleukin-1 beta (IL1B) and modulates a variety of interleukin-1-related immune and inflammatory responses, particularly in the acute phase of infections and inflammation. Several alternatively spliced transcript variants encoding different isoforms are known.

The L1RN gene and five other closely related cytokine genes form a gene cluster spanning approximately 400 kb on chromosome 2. Polymorphism of this gene has been reported to be associated with increased risk of osteoporotic fractures and gastric cancer.

Diseases associated with IL1RN include.

• DIRA (Osteomyelitis, Sterile Multifocal, With Periostitis And Pustulosis).

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.