STXBP2 and hemophagocytic syndrome: While the current study showed that FMF patients carried a large spectrum of variants in several inflammatory genes, certain variants seem to be quite prevalent in patients carrying a single or no mutation in MEFV gene including variants in the 4 genes (PRF1, STXBP2, RAB27A and UNC13D) associated with FHL and the novel variant that we have discovered in the IL1RL1 gene.