We aimed to compare whether carriers for the MEFV mutations display an increase or decrease in certain features. We compared the frequency of a number of inflammatory symptoms and diseases in carriers and a control population.A questionnaire was designed to be applied to parents of children with FMF and a control group of parents. Clinical features and some diseases including the frequency of febrile episodes, abdominal pain, arthralgia, prophylaxis with penicillin, acute rheumatic fever, rheumatoid arthritis, vasculitis, spondyloarthropathy, urinary tract infection, asthma, allergy, irritable bowel disease, appendectomy and tonsillectomy were inquired. 676 parents of 440 children with FMF were surveyed in this study. Controls (n: 774) were selected as parents of healthy children.The presence of febrile episodes more than four per year, arthralgia, past diagnosis for acute rheumatic fever, rheumatoid arthritis and prophylaxis of penicillin, acute rheumatic fever, and rheumatoid arthritis were significantly higher in asymptomatic parents for the MEFV mutations compared to controls. The frequency of allergy was found to be significantly lower in the asymptomatic parents as compared to controls. There was no significant difference at the frequency of urinary tract infection and tonsillectomy between the parents of the patents and controls.We suggest that one MEFV mutation may indeed be conferring a heightened inflammation as suggested by the increased frequency in inflammatory symptoms. The carrier status for MEFV mutations seem to be unique, in that they cause an alteration in the state of "health".