A great mimic
This is a hereditary deficiency in pyrin, which is the brakes on the acute inflammatory response.
Episodes of pain in one place -- one side of the chest, the abdomen, a joint, etc -- are accompanied by fever
. It seems mild, but especially untreated, tends to produce amyloidosis
which is first crippling and then lethal. A few genetic diseases are similar, and fmf often takes years to diagnose.