Mutations in NLRC4 cause autoinflammatory syndromes

Two new autoinflammatory syndromes, caused by different mutations in the NLRC4 gene are reported in two independent studies published online this week in Nature Genetics. Autoinflammatory syndromes are a recently discovered group of illnesses that cause systemic inflammation due to problems with the innate immune system.

The protein produced from the NLRC4 gene is one of several proteins, which make up the inflammasome, a protein complex that plays a central role in the innate immune response. Mutations in some inflammasome proteins can cause autoinflammatory diseases, which are also known as periodic fever syndromes.

In one study, Richard Lifton and colleagues describe members of a family with a novel type of periodic fever syndrome, which is accompanied by serious gastrointestinal complications and chronic inflammation. They find that the syndrome is caused by a single mutation in NLRC4.

In a separate study, Scott Canna and colleagues describe a similar, but less severe syndrome in a seven-month old, which is caused by a different mutation in NLRC4. Both groups found that the mutations cause the inflammasome to be constantly active.

Canna and colleagues also reported that they were able to alleviate most of the symptoms of periodic fever syndrome in one patient by treating her with a drug that blocks the action of specific cytokines (inflammation-causing proteins released by the inflammasome). These findings suggest a potential treatment option for patients with these mutations.