In general, variants common in healthy population are polymorphism but there are exceptions such as MEFV p.Glu148Gln (MAF in global healthy population = 0.13) very common in Asian populations, although rare in European (MAF = 0 in the IBS population) which is found in 14% of Spanish FMF patients31, 32. Here, MEFV is linked to familial Mediterranean fever.