# Familial Mediterranean fever in Armenian children with inflammatory bowel disease

## TL;DR

This study found a high frequency of MEFV gene mutations and FMF in Armenian children with IBD, suggesting these mutations may influence the disease's course rather than cause it.

## Contribution

The study highlights the role of MEFV mutations as disease modifiers in pediatric IBD, particularly in Armenian populations.

## Key findings

- MEFV mutations were found in 53.6% of Armenian pediatric IBD patients, especially in those with ulcerative colitis.
- 36.2% of IBD patients had FMF, and many with MEFV mutations had very early-onset IBD and carried the M694V mutation.
- MEFV mutations were not linked to IBD type but were associated with atypical disease courses and treatment resistance.

## Abstract

Inflammatory bowel disease (IBD) and familial Mediterranean fever (FMF) are inflammatory diseases with complex interactions among genetic, immune, and environmental factors. FMF is a monogenic autoinflammatory disease, characterized by recurrent febrile attacks and polyserositis, and is manifested mainly in childhood. FMF is widespread in Armenia. There are reports on the concurrent occurrence of FMF and IBD. MEFV gene mutations may have a disease-modifying effect on IBD. We have investigated the frequency of MEFV mutations and FMF in Armenian children with IBD and their influence on the clinical course. A total of 69 untreated IBD patients under 18 years of age were enrolled: 52.1% (36) had ulcerative colitis (UC), 21.7% (15) had Crohn's disease (CD), and 26.0% (18) had unclassified colitis (IBD-U). The frequency of FMF among them was 36.2% (25/69), and MEFV mutations were identified in 53.6% (37/69). The highest rate of MEFV mutations and FMF was in UC patients (61.1% and 41.6% respectively). In all, 56.7% (21/37) of IBD patients with MEFV mutations had M694V mutated alleles, mainly in compound heterozygous and heterozygous states. There were no associations in the group of IBD patients with coexisting FMF (25), either between any MEFV mutation and type of IBD or coexistence of FMF. Overall, 36.0% (9/25) of them developed VEO IBD and carried mainly the M694V mutation. We concluded that the carrier frequency of MEFV mutations among Armenian pediatric IBD patients was rather high (53.6%), especially for UC. It was suggested that the MEFV gene is not necessarily a susceptibility gene but most likely modifies the course of IBD. MEFV genetic testing was recommended for Armenian pediatric IBD patients, especially for VEO UC and IBD-U, atypical IBD course, or resistance to the conventional treatment. They should also be asked for isolated febrile attacks, recurrent arthritis, and family history, even in the absence of FMF typical symptoms, to rule out FMF and its complications.