What are the genetic changes related to tumor necrosis factor receptor-associated periodic syndrome ?
TRAPS is caused by mutations in the TNFRSF1A gene. This gene provides instructions for making a protein called tumor necrosis factor receptor 1 (TNFR1). This protein is found within the membrane of cells, where it attaches (binds) to another protein called tumor necrosis factor (TNF). This binding sends signals that can trigger the cell either to initiate inflammation or to self-destruct. Signaling within the cell initiates a pathway that turns on a protein called nuclear factor kappa B that triggers inflammation and leads to the production of immune system proteins called cytokines. The self-destruction of the cell (apoptosis) is initiated when the TNFR1 protein, bound to the TNF protein, is brought into the cell and triggers a process known as the caspase cascade.  Most TNFRSF1A gene mutations that cause TRAPS result in a TNFR1 protein that is folded into an incorrect 3-dimensional shape. These misfolded proteins are trapped within the cell and are not able to get to the cell surface to interact with TNF. Inside the cell, these proteins clump together and are thought to trigger alternative pathways that initiate inflammation. The clumps of protein constantly activate these alternative inflammation pathways, leading to excess inflammation in people with TRAPS. Additionally, because only one copy of the TNFRSF1A gene has a mutation, some normal TNFR1 proteins are produced and can bind to the TNF protein, leading to additional inflammation. It is unclear if disruption of the apoptosis pathway plays a role in the signs and symptoms of TRAPS.