Adult Familial Mediterranean Fever (FMF): is a single MEFV mutation sufficient to cause severe disease?

Article title: Clinical characteristics and outcomes of adult FMF patients: comparison between those with one versus two

pathogenic MEFV exon 10 mutations

First author: Anaël Dumont

Journal: Joint Bone Spine

Link to the article: doi.org/10.1016/j.jbspin.2025.105850

Author of the abstract: Rim BOURGUIBA

Introduction

Familial Mediterranean Fever (FMF) is an autoinflammatory disease caused by mutations in MEFV. While two pathogenic mutations typically lead to a classic and more severe phenotype, the clinical expression in patients with only one pathogenic mutation remains debated. This study compared adult FMF patients according to whether they carried one or two pathogenic MEFV mutations.

Methods

A French single‑center retrospective cohort included 581 adult FMF patients: 178 with a single pathogenic mutation and 403 with two pathogenic mutations. Diagnosis used Eurofever/PRINTO criteria, and all patients underwent MEFV sequencing. A focused analysis compared M694V/E148Q versus M694V/WT.

Results

Compared with biallelic patients, heterozygous patients were older at diagnosis and disease onset, had more personal and family history of recurrent aphthous stomatitis, and a higher BMI. No AA amyloidosis was observed in heterozygotes, and they required lower colchicine doses. These differences remained significant after adjustment for age at onset. No clinical difference was found between M694V/E148Q and M694V/WT.

Conclusion

Adult FMF patients with a single pathogenic MEFV mutation show distinct clinical features and outcomes compared with those carrying two mutations. Findings highlight FMF phenotypic heterogeneity and support tailoring management to the patient’s genetic profile.

FMF adulte : une seule mutation MEFV suffit‑elle à rendre la maladie sévère.

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