The hereditary periodic fever syndromes: molecular analysis of a new family of inflammatory diseases.

The hereditary periodic fever syndromes are a group of Mendelian disorders characterized by episodic fever and serosal or synovial inflammation. Familial Mediterranean fever (FMF) and the hyperimmunoglobulinemia D and periodic fever syndrome are both recessively inherited, while three dominantly inherited syndromes have been described, the best-characterized of which is familial Hibernian fever (FHF). The last year has seen two major developments in this field: the FMF gene was identified on chromosome 16p by positional cloning, and a second major periodic fever locus was mapped to distal chromosome 12p. The FMF gene (MEFV) encodes a novel 781 amino acid protein; to date, eight different missense mutations and a number of polymorphisms have been described. Seven of the eight mutations occur within a region of 82 amino acids near the C-terminus. Computational analysis of the conceptual protein reveals five different domains/motifs compatible with a nuclear effector function. MEFV is expressed preferentially in granulocytes and myeloid bone marrow precursors, giving rise to speculation that the protein may serve as a transcriptional regulator of inflammation in granulocytes. The second periodic fever locus was mapped by two different groups: one studying FHF, the other studying a similar dominantly inherited syndrome designated familial periodic fever. Both genes map to the same 19 cM region on distal chromosome 12p, strongly suggesting a common locus. The molecular characterization of the periodic fever genes should provide important new insights into the regulation of inflammation in general.