Possible protection against asthma in heterozygotes for familial Mediterranean fever

Abstract

To identify a specific heterozygote advantage in familial Mediterranean fever (FMF), responsible for the high carrier rate of 1/6 in North African Jews, we studied the morbidity and mortality of 148 parents of affected patients and of 148 ethnically matched control persons. Our data demonstrate an apparently reduced prevalence of asthma in the heterozygotes compared with the control persons (3 vs. 6). There were no significant differences between the 2 groups in fertility rate, number of pregnancies and deliveries, or the prevalence of common diseases. Our data are in agreement with previous studies which demonstrated decreased asthma prevalence in FMF patients. It further confirmed, these findings suggest that identification of the FMF gene on 16p may provide an insight into asthma.

The spectrum of Familial Mediterranean Fever (FMF) mutations

“…Some authors have suggested that mutations in the MEFV gene may confer certain advantages to the individual that could account for the very high carrier rate in these populations. 6,57 Severity of the disease course would basically depend on the combination and the number of mutated alleles involved in the patient genotype. Additional alleles within and/or outside the gene would further modify the phenotype, promoting or preventing chronic complications.…”

Lung Involvement in Children with Hereditary Autoinflammatory Disorders

“…Danon et al, in 1990, using the Israeli army database, demonstrated for the first time a significantly lower prevalence of asthma in FMF patients compared to the general prevalence [19]. Furthermore, another study by Ozyilkan et al confirmed the same finding in a group of 100 FMF patients without asthma [20], and, in addition, Brenner-Ullman et al found an apparently reduced prevalence of asthma in the FMF heterozygotes compared with controls [21]. Although the question of protection against asthma in FMF remains open, the possibility of a negative association between the two diseases is appealing and requires further confirmation studies.…”

MEFV Mutation Carriers and Diseases Other than Familial Mediterranean Fever: Proved and Non-Proved Associations; Putative Biological Advantage

“…This advantage for the carriers of MEFV mutations is not obvious. It has been suggested that heterozygotes were possibly better protected against asthma [65,66] and allergic rhinitis [67]. The decreased allergic response in FMF patients and carriers, if proven, may be a result of, rather than the cause of, underlying patho-physiology.…”