What are the genetic changes related to familial cold autoinflammatory syndrome ?
Mutations in the NLRP3 and NLRP12 genes cause familial cold autoinflammatory syndrome. The NLRP3 gene (also known as CIAS1) provides instructions for making a protein called cryopyrin, and the NLRP12 gene provides instructions for making the protein monarch-1.  Cryopyrin and monarch-1 belong to a family of proteins called nucleotide-binding domain and leucine-rich repeat containing (NLR) proteins. These proteins are involved in the immune system, helping to regulate the process of inflammation. Inflammation occurs when the immune system sends signaling molecules and white blood cells to a site of injury or disease to fight microbial invaders and facilitate tissue repair. When this has been accomplished, the body stops (inhibits) the inflammatory response to prevent damage to its own cells and tissues.  Cryopyrin is involved in the assembly of a molecular complex called an inflammasome, which helps start the inflammatory process. Mutations in the NLRP3 gene result in a hyperactive cryopyrin protein that inappropriately triggers an inflammatory response.  Monarch-1 is involved in the inhibition of the inflammatory response. Mutations in the NLRP12 gene appear to reduce the ability of the monarch-1 protein to inhibit inflammation.  Impairment of the body's mechanisms for controlling inflammation results in the episodes of skin rash, fever, and joint pain seen in familial cold autoinflammatory syndrome. It is unclear why episodes are triggered by cold exposure in this disorder.