<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by tumor necrosis factor receptor-associated periodic syndrome ? [/INST] TRAPS has an estimated prevalence of one per million individuals; it is the second most common inherited recurrent fever syndrome, following a similar condition called familial Mediterranean fever. More than 1,000 people worldwide have been diagnosed with TRAPS. </s>