MEFV and Arthritis: Familial Mediterranean fever (OMIM 249100) is transmitted by autosomal recessive inheritance and, in its most frequent and classic phenotype, is characterized by recurrent acute fever episodes, polyserositis, arthritis, and erysipelas-like erythema [15]: it is due to the presence of mutations (among the 200 identified to date) in the MEFV (from MEditerranean FeVer) gene which encodes the protein pyrin, also known by its European name “marenostrin” [16, 17] (Table 1).