Two elderly cases of familial mediterranean fever with rheumatoid arthritis.

Familial Mediterranean fever (FMF) is a genetic autoinflammatory disorder that usually develops before 20 years of age and is characterized by periodic fever with serositis and arthritis. Both FMF and rheumatoid arthritis (RA) involve arthritis; however, their coexistence is rare. We describe two RA patients with an MEFV mutation in exon 2, who were diagnosed with FMF at an age of over 50 years.