Familial Mediterranean fever (FMF) is the most prevalent type of hereditary recurrent fever. Although the inflammatory attacks that characterize the disease may sometimes be debilitating, reactive amyloidosis remains the most serious manifestation of FMF. Daily treatment with colchicine can prevent both the attacks and amyloid deposition, but FMF-associated amyloidosis has not been eradicated and is still a cause of chronic renal failure in children and adults. The discovery of the gene responsible for FMF, Mediterranean fever gene (MEFV), and of associated mutations represents a major advance that now allows researchers to establish a strong, although nonexclusive association between one specific mutation, M694V, and the amyloid phenotype.