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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Iron Deficiency in Familial Mediterranean Fever: A Studyon 211 Adult Patients From the JIR Cohort

First author: Ilenia Di Cola et al

Review: American Journal of Hematology

Link to article: https://doi.org/10.1002/ajh.27549

Familial Mediterranean Fever (FMF) is the most common monogenic autoinflammatory disease worldwide, associated with mutations in the MEFV gene. Patients experience recurrent and self-limited episodes of fever, abdominal pain, and chest pain. There is no specific association between anemia and FMF, except that patients with chronic inflammation may have inflammatory microcytic anemia.

However, chronic anemia can lead to fatigue, and fatigue is known to be a trigger for FMF. Therefore, patients with fatigue due to anemia may experience more frequent flare-ups of the disease and a reduced quality of life. Iron deficiency can cause fatigue even in the absence of anemia. Fatigue is also commonly reported in FMF. Therefore, it may be beneficial to check for iron deficiency without anemia as one of the causes of fatigue in FMF, especially since fatigue can be considered a trigger for their flare-ups.

Our study explores the prevalence of iron deficiency in 211 adult patients with Familial Mediterranean Fever (FMF). The main goal was to determine the association between iron deficiency (defined by ferritin < 27 ng/mL) and various clinical, biological, and therapeutic parameters.

In total, 31.8% of FMF patients had ferritin < 27 ng/mL, mostly young women. Iron deficiency, even without anemia, potentially contributes to fatigue, a frequent trigger of inflammatory flare-ups. Possible causes include excessive menstrual losses not compensated by a diet rich in iron, low consumption of animal proteins, or digestive bleeding exacerbated by the use of NSAIDs.

Patients with low ferritin had lower hemoglobin (Hb) levels and BMI, and required higher doses of colchicine (2 mg/day on average). The impact of colchicine on intestinal iron absorption remains to be studied.

This work highlights the importance of monitoring ferritin levels in Familial Mediterranean Fever (FMF) due to the simplicity and global accessibility of this test, including in emerging countries. In the case of significant iron deficiency, supplementation is recommended to alleviate symptoms such as fatigue and anemia, which can trigger FMF flare-ups and maintain a vicious cycle of fatigue in patients.

Iron deficiency in FMF.pdf

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