MEFV and rheumatoid arthritis: These MEFV mutations have already been reported by some studies such as Migita et al. demonstrated that MEFV mutations are not rare in RA and that the allele frequencies of R408Q, P369S, E148Q, L110P mutations were 5.6%, 6.7%, 24.2%, 9.5% respectively in patients with RA and that the mutation rate was comparable between RA and healthy controls and suggest that MEFV mutations may not be a genetic factor affecting susceptibility to RA [16].