The MEFV gene pathogenic variants and phenotype-genotype correlation in children with familial Mediterranean fever in the Çanakkale population

The Impact of Different MEFV Genotypes on Clinical Phenotype of Patients with Familial Mediterranean Fever: Special Emphasis on Joint Involvement

Familial Mediterranean Fever (FMF) is the most common monogenic autoinflammatory disease worldwide. In this retrospective cohort study, we aimed to assess the effects of various MEFV genotypes on the clinical characteristics of the patients, with a special focus on the joint involvement. In total, 782 patients with FMF were categorized into 3 groups according to the MEFV mutation; Group 1: Patients homozygous for M694V; Group 2: Patients carrying other pathogenic MEFV variants in exon 10 in homozygous or compound heterozygous states; and Group 3: FMF patients with other variants or without mutations. Clinical and demographic findings were compared between groups. Among the 782 FMF patients, total frequency of arthritis was 237 (30.3%): 207 (26.4%) were acute monoarthritis and 67 (8.5%) were chronic arthritis. Both the frequency of arthritis (acute and/or chronic) (40.4% vs. 24.8% vs. 26.7%; p:0.001) and acute monoarthritis (35.4% vs. 20% vs. 23.7%; p:0.001) were significantly higher in Group 1 than in the other groups. FMF patients with chronic arthritis showed a distinct juvenile idiopathic arthritis (JIA) distribution pattern with a more frequent enthesitis-related arthritis (ERA) subtype (43.2%). HLA-B27 was positive in 24% of the ERA patients.Conclusion: Homozygous M694V mutation is associated with a more frequent and longer acute monoarthritis comparing to other MEFV genotypes. In addition, the risk of chronic arthritis seems not related to the MEFV mutations. However, FMF patients with chronic arthritis show a distinct ILAR JIA distribution pattern with a more frequent ERA and undifferentiated arthritis subtype. What is known: • Homozygous M694V mutation is associated with a more frequent and longer acute monoarthritis What is new: • FMF patients with chronic arthritis show a distinct ILAR JIA distribution pattern with a more frequent ERA subtype • ERA patients with negative HLA-B27 antigen should also be assessed for polyserositis episodes of FMF, especially in countries with high FMF carrier frequency.

The clinical effect of gene mutations in familial Mediterranean fever disease

BACKGROUND

Familial Mediterranean fever (FMF) is a self-limiting, autoinflammatory disease characterized by inflammation of the serosal surfaces and recurrent episodes of fever. The aim of this study is to determine the effect of genetic mutations on clinical features in children with FMF.

METHODS

A total of 303 patients aged 0-18 years, who were diagnosed with FMF, according to Yalcinkaya-Özen diagnostic criteria and whose Mediterranean fever gene (MEFV) analysis was studied, were evaluated retrospectively. The clinical and demographic characteristics of the patients and the relationship between common alleles and genotypes were investigated.

RESULTS

The most common mutation in patients was M694V heterozygous. When the patients were divided into four groups, M694V homozygous, M694V heterozygous, M694V/other allele combined heterozygous, and other mutations, Arthritis was statistically significantly higher in the group that was M694V homozygous compared to the other groups. It was observed that the presence of the M694V allele significantly increased the frequency of periodic fever, aphthous stomatitis, pharyngitis, adenitis syndrome. The frequency of arthritis was significantly higher in patients who were E148Q homozygous than in patients who were heterozygous. Appendectomy history was significantly higher in the group carrying the V726A allele.

CONCLUSIONS

FMF disease and the effect of genetics on the disease can be better understood, thanks to studies evaluating the genotype-phenotype relationship. In this regard, we believe that studies evaluating the clinical and genotype relationship with a large series are needed.

The Spectrum of MEFV Gene Mutations and Genotypes in the Middle Northern Region of Turkey

Objective

Familial Mediterranean fever (FMF) is a common, inherited, autosomal recessive inflammatory disease in children. The diagnosis of FMF is based on clinical features and positive family history supported with genetic testing. This study aimed to determine the frequency and distribution of Mediterranean fever (MEFV) gene alterations of a city in Northern Anatolia.

Materials and Methods

We evaluated MEFV gene mutations in 374 children preliminary diagnosed as FMF by a commercial kit based on real-time polymerase chain reaction technique in a one-year period, and screened 12 mutations.

Results

At least one mutation was detected in 213 patients (57%) and 38 genotypes with 11 distinct mutations.A total of 137 (64. 3%) of mutation-positive children were heterozygous, 45 (21. 1%) were compound heterozygous, and 2 (0.9%) were complex heterozygous; and 14 (6.4%) patients were homozygous, 6 (2.8%) were compound homozygous, and 3 (1.4%) were complex homozygous. With a frequency of 50.1%, R202Q was the most common mutation. Also, R202Q/M694V was the most common compound heterozygous genotype. In 43 alleles, R202Q-M694V mutations were found to be in linkage disequilibrium. In our cohort, M694V, E148Q, V726A, and M680I (G/C) were other common mutations; whereas F479L, A744S, K695R, P369S, M694I, and R761H were the rare mutations. None of our patients had M680I (G/A) mutation.

Conclusion

We determined the most common MEFV alteration prevalence in children of our region for the first time. The high R202Q mutation and linkage disequilibrium (LD) rates were the remarkable results of this study.

Prevalence of MEFV gene mutations in a large cohort of patients with suspected familial Mediterranean fever in Central Anatolia

BACKGROUND

Familial Mediterranean fever (FMF), an autosomal recessive, autoinflammatory disease that is common in Arabs, Jews, Armenians and Turks, is caused by mutations in the MEFV gene, which encodes a protein called pyrin. The disease is characterised by recurrent fever, peritonitis, pleuritis, abdominal pain and arthralgia.

OBJECTIVE

Determine the distributions of MEFV mutations and their relationship with clinical manifestations.

DESIGN

Retrospective, descriptive.

SETTING

Turkish community.

SUBJECTS AND METHODS

The study included patients with complaints related to FMF who were admitted to the research hospital of Cumhuriyet University between 2005 and 2017. FMF was diagnosed by physical examination using the Tel-Hashomer criteria. MEFV mutations were detected by reverse hybridization strip assay and pyrosequencing.

MAIN OUTCOME MEASURE

The prevalence of specific MEFV gene mutations in a large cohort of Middle Anatolia.

SAMPLE SIZE

10 033 patients admitted, 1223 with confirmed mutations.

RESULTS

Of 1684 patients diagnosed by Tel-Hashomer criteria, mutation screening confirmed that 1223 patients (72.6%) had FMF. Male/female ratio of the FMF patients was 1.3:1. One or more FMF mutations were found in 4497 patients (44.8%). 3262 had heterozygous or carrier mutations, 821 had compound heterozygous mutation, 381 had homozygous mutations, and 21 had triple mutations. Sixty-six percent had a family history of the disease and 13.7% of the patients had parental consanguinity. Main symptoms found in the patients were abdominal pain (85.2%), fever (84%), chest pain (30.2%), arthralgia (28.6%), rash or erysipelas-like erythema (8.2%). The most common mutation in this population was M694V (39%) of 5753 alleles.

CONCLUSION

M694V was the most frequent mutation in our population (Middle Anatolia, Turkey) and cause severe forms of the disease. Patients with E148Q, V726A and R761H mutations may have milder FMF symptoms. There was a high rate of carriers in our study group.

LIMITATIONS

Amyloidosis, an important complication of the disease, needs to be analyzed.

CONFLICT OF INTEREST

None.

Familial Mediterranean fever in Jordanian Children: single centre experience

Background

Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder caused by mutations in the Mediterranean Fever (MEFV) gene. The disease is especially common among Mediterranean ancestry, mostly Armenian, Turkish, Jewish and Arab populations. Our aim is to describe clinical phenotype, and genotype of FMF in the Jordanian children.

Patients and Methods

A retrospective analysis was conducted on paediatric patients who were below 14 years of age and diagnosed as FMF at Queen Rania Children's Hospital in Jordan between 2014 and 2017.

Results

A total of 196 paediatric patients diagnosed with FMF were included; 54% females and 46% males. The mean age of patients at time of study was 7.8 years, at disease onset was 4.9 years, and at time of diagnosis was 6.6 years. The most common presenting features were abdominal pain (91.8%), fever (73%), arthralgia (16.8 %), and myalgia (12.8%). MEFV gene mutations were homozygous in 47 (24%) patients, heterozygous in 87 (44.4%) patients, compound heterozygous in 55 (28.1%), and negative genotype in 7 (3.6%) patients. Five mutations were the most frequent; M694V, V726A, E148Q, M680I, M694I. All patients were colchicine responsive. We reported only one case of amyloidosis.

Conclusion

The five FMF founder mutations: M694V, V726A, E148Q, M680I, and M694I were the most common in Jordanian children, but had a different order from other ethnic groups.