The MEFV gene carries the instructions for production of a protein called pyrin, named for pyrexia, a medical term for fever.
Research has shown that pyrin has some function in controlling neutrophils, which are the white blood cells that move into an area of the body affected by stress or trauma.
In a person with a normal immune system, some inflammation may follow stress or trauma, but the pyrin protein is responsible for shutting down the response of neutrophils once they are no longer needed.
An abnormal pyrin protein associated with FMF may be partly functional but unstable.
In some instances, the abnormal pyrin itself seems to be "stressed", and loses its ability to regulate the inflammatory response to trauma.