Frequency of mutations in Mediterranean fever gene, with gender and genotype–phenotype correlations in a Turkish population

Disease severity and genotype-phenotype correlation in adult patients with familial Mediterranean fever

OBJECTIVES

To assess the relationships of disease severity with genotype and phenotype in adult familial Mediterranean fever patients.

METHODS

Two-hundred seventy-five patients included in the study were divided into four groups according to their mutations: Group 1, M694V homozygous; Group 2, M694V-other; Group 3, other-other; and Group 4, no meaningful gene variants. Disease severity was evaluated using the Pras disease severity score. The association between Pras scores and other possible predictors was assessed by the multiple linear regression analysis.

RESULTS

In this study, 12.4% of all patients were in Group 1, 55.3% were in Group 2, 26.5% were in Group 3, and 5.8% were in Group 4. Pras scores were higher in Group 1 than in Groups 2, 3, and 4 (post hoc pairwise comparisons; P = .001, P < .001, and P = .001, respectively). Age at disease onset and age at diagnosis were found moderately and strongly correlated with Pras scores. Patients with moderate and severe disease were intensely involved in Group 1.

CONCLUSIONS

Higher Pras scores, earlier age of symptoms and diagnosis, more frequent arthritis and erysipelas-like erythema, and higher colchicine dose are closely associated with M694V homozygous familial Mediterranean fever patients. These patients also have mostly moderate and severe disease severity.

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.

Familial mediterranean fever: assessment of clinical manifestations, pregnancy, genetic mutational analyses, and disease severity in a national cohort

The aims of this study were to investigate the main clinical and laboratory features, including pregnancy and genetic analysis, of Turkish Familial Mediterranean Fever (FMF) patients and to analyze the relationships between genotypic features, age of disease onset, clinical findings, and disease severity. A study was planned within a national network of 22 different centers. Demographics, clinical and laboratory findings, attack characteristics, drugs, pregnancy and birth history, disease severity, and gene mutation analyses were evaluated. Disease severity, assessed using a scoring system developed by Pras et al., was evaluated in relation to gene mutations and age of disease onset. A total of 979 patients (643 females and 336 males; mean age: 35.92 ± 11.97 years) with FMF were included in the study. Of a total of 585 pregnancies, 7% of them resulted in preterm birth and 18.1% resulted in abortions. During pregnancy, there was no FMF attack in 61.4% of patients. Of the MEditerranean FeVer (MEFV) mutations, 150 (24.3%) cases were homozygous, 292 (47.3%) cases were heterozygous, and 175 (28.4%) were compound heterozygous. Patients with homozygous gene mutations had more severe disease activity, earlier age of disease onset, higher rates of joint and skin involvement, sacroiliitis, and amyloidosis. Patients with compound heterozygous genotype displayed severe disease activity in close resemblance to patients with homozygous mutation. In addition, patients with compound heterozygous mutations had higher rates of protracted febrile myalgia and elevated fibrinogen levels. In 63.9% of compound heterozygous patients, age of onset was < 20 years, with greater disease severity, and high rates of attack frequency and colchicine resistance. Our results suggest that indicators for disease severity include early onset of disease and homozygous gene mutations. Furthermore, patients with compound heterozygous mutations displayed significant presentations of severe disease activity.

Mediterranean fever (MEFV) gene profile and a novel missense mutation (P313H) in Iranian Azari-Turkish patients

BACKGROUND

Familial Mediterranean fever (FMF) is common in Azari-Turkish people, one of the biggest ethnic groups in Iran. In this study, we sought to investigate the mutation spectrum of the MEFV gene and any genotype-phenotype correlations.

METHODS AND MATERIALS

400 unrelated Azari-Turkish FMF patients were analyzed in this study. Mutations in exons 2, 3, 5, and 10 of the MEFV gene were investigated using direct Sanger sequencing, and their correlations with the clinical features of the patients were analyzed.

RESULTS

At least one mutation was detected in 248 (62%) patients. The most common mutations were M694V (26.25%) and E148Q (24.75%), respectively. Abdominal pain (65.2%) and fever 204 (51%) were the most frequent clinical problems in all subjects. The analysis recognized a novel missense mutation in the coding region of the MEFV gene, named P313H, which is the first report of a new mutation in exon 2 of the MEFV gene in an Azari-Turkish family.

CONCLUSION

Genotype-phenotype correlations obtained from this study would be helpful in the diagnosis and management of FMF patients in clinical situations. This novel missense mutation may provide useful evidence for further studies of FMF pathogenesis.

The distribution of MEFV mutations in Turkish FMF patients: multicenter study representing results of Anatolia

Background/aim

The distribution of Mediterranean fever (MEFV) gene mutations in Turkish familial Mediterranean fever (FMF) patients varies according to geographic area of Turkey. There is a need for highly representative data for Turkish FMF patients. The aim of our study was to investigate the distribution of the common MEFV mutations in Turkish FMF patients in a nationwide, multicenter study.

Materials and methods

Data of the 2246 FMF patients, from 15 adult rheumatology clinics located in different parts of the country, were evaluated retrospectively. The following mutations have been tested in all patients: M694V, M680I, M694I, V726A, and E148Q.

Results

There were 1719 FMF patients with available genetic testing. According to the genotyping, homozygous M694V, present in 413 patients (24%), was the most common mutation . One hundred and fifty-four (9%) of patients had no detectable mutations. Allele frequencies of common mutations were: M694V (n = 1529, 44.5%), M680I (n = 423, 12.3%), V726A (n = 315, 9.2%), E148Q (n = 214, 1%), and M694I (n = 12, <1%).

Conclusion

In this large-scale multicenter study, we provided information about the frequencies of common MEFV gene mutations obtained from adult Turkish FMF patients. Nearly half of the patients were carrying at least one M694V mutations in their alleles.

Neonatal onset familial Mediterranean fever

Objectives: Familial Mediterranean fever (FMF) is an autosomal recessive disease characterised by recurrent, self-limited attacks of fever with serositis. Recently, it was shown that FMF patients with early disease onset have more severe disease. The aim of this study was to describe the demographic, clinical and genetic features of FMF patients who had disease onset during the neonatal period. Methods: Medical records of all patients diagnosed as FMF and had been seen in the outpatient clinic of Paediatric Rheumatology department between January 2013 and January 2014 were retrospectively evaluated. Patients with disease onset during the first month of life were included to the study. Results: Among 317 patients; 19 (12 males) were included to the study. Approximately 60% of the patients had family history of FMF. Homozygous p.M694V mutation was detected in 42% of the cases. Thirteen patients present with attacks of fever and remaining had attacks in the form of restlessness, resembling infantile colic starting in the neonatal period. Majority of these patients developed classical abdominal attacks between the ages of 1 and 2.5 years. The diagnosis of FMF was significantly delayed; the median age at onset of therapy was 3.5 years (range 7 months-17 years). Conclusion: Patients with FMF could have complaints even in the neonatal period. Homozygous p.M694V mutation is a prominent mutation in this group of patients. In order to prevent diagnostic delay physicians dealing with these type of patients should be more vigilant.

Lack of clear and univocal genotype-phenotype correlation in familial Mediterranean fever patients: A systematic review

Familial Mediterranean fever (FMF) is the most common autosomal recessive autoinflammatory disease. To date, following the isolation of more than 280 MEFV sequence variants, the genotype-phenotype correlation in FMF patients has been intensively investigated; however, an univocal and clear consensus has not been yet reached. Thus, the aim of this systematic review was to analyze the available literature findings in order to provide to scientific community an indirect estimation of the impact of genetic factors on the phenotypic variability of FMF. This systematic review has been conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. The p.M694V mutation was reported to have a relatively severe clinical course, similarly, patients homozygous for M694I and M680I, or carrying a combination of both at codons 694 and 680, have a severe disease. Also, patients homozygous for M694V and V726A variants experienced more severe clinical picture. Conversely, heterozygous p.V726A and p.E148Q genotypes have been correlated with a milder disease course. At present, doubts remain on the potential pathogenic role of E148Q variant. The heterogenity in clinical FMF manifestations reflects the changes occuring in repertoire of mutations. We believe that clinical criteria and gene tests, enhancing each other, could better support the diagnosis of FMF.

MEFV mutations and their relation to major clinical symptoms of Familial Mediterranean Fever

Familial Mediterranean fever is a common hereditary disease in Turkey. To date, different mutational spectrum of MEFV gene was observed in studies carried out in different regions of Turkey but in most of these studies association of clinical symptoms of FMF to mutant genotypes have not been investigated in details. Here we report the MEFV gene variations in exons 2, 3, 5 and 10 and their relations to major clinical symptoms of FMF in 514 unrelated (245 males and 269 females) Turkish patients. MEFV mutations were found in 45% (n=230) of patients and 55% (n=284) of patients did not have any mutations. One hundred and thirty-seven (60%) patients were heterozygous, 57 (24.7%) patients were compound heterozygous, 33 (14%) patients were homozygous and 3 (1.3%) patients were having a complex genotype. Allele frequencies of MEFV mutations were M694V (48%), E148Q (18%), M680I (15%), V726A (12.5%), P369S (3.3%), R761H (0.9), K695R (0.9), E148V (0.9) and A744S (0.5%). Abdominal pain (76%) and fever (58%) were two most seen complications among patients followed by arthritis (28%) and chest pain (19%). Almost all major clinical symptoms of FMF were higher in patients with one or more M694V or M680I mutant allele. In contrast, patients having E148Q or V726A mutant allele showed fewer clinical FMF symptoms. Patients with P369S have higher abdominal pain, chest pain and fever than expected. Arthritis was high in K695R heterozygous genotype. One hundred and eighteen patients were carrying more than one polymorphic allele. The most common polymorphism was R202Q (13%). In addition, a novel heterozygous polymorphism at 564th nucleotide (C>T) of exon2 were found in 2 patients.

Association between sequence variations of the Mediterranean fever gene and the risk of migraine: a case-control study

Migraine pathogenesis involves a complex interaction between hormones, neurotransmitters, and inflammatory pathways, which also influence the migraine phenotype. The Mediterranean fever gene (MEFV) encodes the pyrin protein. The major role of pyrin appears to be in the regulation of inflammation activity and the processing of the cytokine pro-interleukin-1β, and this cytokine plays a part in migraine pathogenesis. This study included 220 migraine patients and 228 healthy controls. Eight common missense mutations of the MEFV gene, known as M694V, M694I, M680I, V726A, R761H, K695R, P369S, and E148Q, were genotyped using real-time polymerase chain reaction with 5' nuclease assays, which include sequence specific primers, and probes with a reporter dye. When mutations were evaluated separately among the patient and control groups, only the heterozygote E148Q carrier was found to be significantly higher in the control group than in the patient group (P=0.029, odds ratio [95% confidence interval] =0.45 [0.21-0.94]). In addition, the frequency of the homozygote and the compound heterozygote genotype carrier was found to be significantly higher in patients (n=8, 3.6%) than in the control group (n=1, 0.4%) (P=0.016, odds ratio [95% confidence interval] =8.57 [1.06-69.07]). However, there was no statistically significant difference in the allele frequencies of MEFV mutations between the patients and the healthy control group (P=0.964). In conclusion, the results of the present study suggest that biallelic mutations in the MEFV gene could be associated with a risk of migraine in the Turkish population. Moreover, MEFV mutations could be related to increased frequency and short durations of migraine attacks (P=0.043 and P=0.021, respectively). Future studies in larger groups and expression analysis of MEFV are required to clarify the role of the MEFV gene in migraine susceptibility.