The Frequency of MEFV Gene Mutations and Genotypes in Sanliurfa Province, South-Eastern Region of Turkey, after the Syrian Civil War by Using Next Generation Sequencing and Report of a Novel Exon 4 Mutation (I423T)

Genetic and clinical features of familial mediterranean fever (FMF) in a homogeneous cohort of patients from South-Eastern Italy

Familial Mediterranean Fever (FMF) is linked with the MEFV gene and is the commonest among monogenic autoinflammatory diseases, with high prevalence in the Mediterranean basin. Although the clinical presentation of FMF has a major role in diagnosis, genotype/phenotype correlations and the role of "benign" gene variants (as R202Q) appear highly variable and incompletely clear, making difficult to select the most effective strategy in the management of patients. Aim of the present study was to investigate the clinical presentation and the genetic background in a homogenous cohort of patients from Apulia (south eastern Italy). We investigated 217 patients with a clinical suspect of autoinflammatory diseases, who were characterized for the occurrence of specific symptoms and with next generation sequencing by a 4-gene panel including MEFV, MVK, NLRP3 and TNFRSF1A. A genetic change was identified in 122 (53.7%) patients, with 161 different MEFV variants recorded in 100 individuals, 10 variants in NLRP3, and 6 each in TNFRSF1A and MVK. The benign variant R202Q was largely prevalent (41.6% of all MEFV variants). When patients were selected according the number of pathogenic MEFV variants (0, 1, or 2 pathogenic variants), results failed to show significant links between the frequency of symptoms and the number of pathogenic variants. Only family history and Pras score (indicative for severity of disease) predicted the presence of pathogenic variants, as compared with carriers of variants considered of uncertain significance or benign. Fever >38 °C and arthralgias appeared more frequently in R202Q-positive patients than in non-R202Q carriers. These two subgroups showed comparable duration of fever, occurrence of myalgia, abdominal and chest pain, Pras, and IFFS scores. In conclusion, results confirm that FMF manifests in mild form in non-middle eastern patients. This possibility partly affects the reliability of clinical criteria/scores. Furthermore, the presence of the R202Q variant might not be completely neutral in selected groups of patients.

MEFV gene allele frequency and genotype distribution in 3230 patients' analyses by next generation sequencing methods

Familial Mediterranean Fever (FMF, OMIM ID: 249100) is the most common autoinflammatory, autosomal recessive disease caused by mutations in the MEFV gene. It is widespread in the Mediterranean, primarily among Turkish, Armenian, Arab and Jewish. This study aims to examine genotype distributions of common MEFV variants in the Turkish population using targeted NGS and to evaluate all rare mutations. It included 3230 people applying to Ege University Children's Hospital Molecular Medicine Laboratory with the suspicion of autoinflammatory disease between 2017 and 2021. MEFV missense variant was detected in 1839 (56.9%) individuals. One or more mutations were found in them. 1063 patients were heterozygous (57.8%), 410 were compound heterozygous (22.3%), 238 were complex genotype (12.9%), and 128 were homozygous (7%). 56 different mutations and 141 genotypes were detected, two of which were novel (p.His87Arg, c.260A > G and p.Leu396Phe, c.1186C > T). These were determined as 6benign, 40 uncertain significant, 3 likely pathogenic and 7 pathogenic according to the ACMG classification. The most common ones were R202Q (n = 1097, 37.48%), E148Q (n = 512, 17.49%), M694V (n = 493, 16.84%), V726A (n = 155, 5.30%), M680I (n = 150, 5.12%), P369S (n = 108, 3.69%), R408Q (n = 95, 3.25%) respectively. They constitute 89.17 % of the entire patient population. In conclusion, DNA variants/mutations in the MEFV gene were evaluated in 3230 patients. To date, no mutation screening has been encountered in such a large population using NGS. Genotype distributions of both common and rare mutations were revealed. The obtained data will hopefully contribute to the future genotype-phenotype studies of FMF disease.

Probability of high-risk genetic matching with oocyte and semen donors: complete gene analysis or genotyping test?

PURPOSE

To estimate the probability of high-risk genetic matching when assisted reproductive techniques (ART) are applied with double gamete donation, following an NGS carrier test based on a complete study of the genes concerned. We then determine the results that would have been obtained if the genotyping tests most widely used in Spanish gamete banks had been applied.

METHODS

In this descriptive observational study, 1818 gamete donors were characterised by NGS. The pathogenic variants detected were analysed to estimate the probability of high-risk genetic matching and to determine the results that would have been obtained if the three most commonly used genotyping tests in ART had been applied.

RESULTS

The probability of high-risk genetic matching with gamete donation, screened by NGS and complete gene analysis, was 5.5%, versus the 0.6-2.7% that would have been obtained with the genotyping test. A total of 1741 variants were detected, including 607 different variants, of which only 22.6% would have been detected by all three genotyping tests considered and 44.7% of which would not have been detected by any of these tests.

CONCLUSION

Our study highlights the considerable heterogeneity of the genotyping tests, which present significant differences in their ability to detect pathogenic variants. The complete study of the genes by NGS considerably reduces reproductive risks when genetic matching is performed with gamete donors. Accordingly, we recommend that carrier screening in gamete donors be carried out using NGS and a complete study with nontargeted analysis of the variants of the screened genes.

Clinical and molecular evaluation of MEFV gene variants in the Turkish population: a study by the National Genetics Consortium

Familial Mediterranean fever (FMF) is a monogenic autoinflammatory disorder with recurrent fever, abdominal pain, serositis, articular manifestations, erysipelas-like erythema, and renal complications as its main features. Caused by the mutations in the MEditerranean FeVer (MEFV) gene, it mainly affects people of Mediterranean descent with a higher incidence in the Turkish, Jewish, Arabic, and Armenian populations. As our understanding of FMF improves, it becomes clearer that we are facing with a more complex picture of FMF with respect to its pathogenesis, penetrance, variant type (gain-of-function vs. loss-of-function), and inheritance. In this study, MEFV gene analysis results and clinical findings of 27,504 patients from 35 universities and institutions in Turkey and Northern Cyprus are combined in an effort to provide a better insight into the genotype-phenotype correlation and how a specific variant contributes to certain clinical findings in FMF patients. Our results may help better understand this complex disease and how the genotype may sometimes contribute to phenotype. Unlike many studies in the literature, our study investigated a broader symptomatic spectrum and the relationship between the genotype and phenotype data. In this sense, we aimed to guide all clinicians and academicians who work in this field to better establish a comprehensive data set for the patients. One of the biggest messages of our study is that lack of uniformity in some clinical and demographic data of participants may become an obstacle in approaching FMF patients and understanding this complex disease.

Sequence analysis in Familial Mediterranean Fever patients with no confirmatory genotype

INTRODUCTION/OBJECTIVES

Familial Mediterranean Fever (FMF) is a genetic disorder of the innate immunity characterized by chronic inflammatory state. The diagnosis is mainly based on clinical criteria and supported by genotyping, especially in atypical phenotypes. The primary objective was to depict the Familial Mediterranean Fever (FMF) genotype of Greek patients and investigate the contribution of Next Generation Sequencing (NGS) beyond the contemporary techniques [(Polymerase Chain Reaction (PCR)/hybridization and Non-Isotopic RNase Cleavage Assay (NIRCA). The secondary objective was to unravel any associations between the mutated genes with the disease course and response to treatment.

METHODS

In this single center, retrospective study 31 patients with clinical diagnosis with FMF, but non-conclusive genetic analysis with PCR/hybridization and NIRCA, underwent NGS genotyping.

RESULTS

PCR/NIRCA detected ≥ 1 mutation in 25/31 patients, most frequently M694V (29%), while NGS in 26/31 (83.9%), most frequently R202Q (61.3%). NGS genetically confirmed the clinical diagnosis (heterozygosity to compound or complex genotype) in 19 (61.3%) patients of our cohort. R202Q was significantly more prevalent by NGS than by contemporary techniques (61.3 vs 12.9%, p = 0.0002) and was associated with FMF. Rare mutations were detected by NGS in 19.2% patients.

CONCLUSION

NGS clarifies the genetic profile of patients with atypical phenotypes and supports therapeutic management decisions. NGS unveiled the frequent involvement of R202Q in the pathogenesis of our FMF patients.

Presentation of a new mutation in FMF and evaluating the frequency of distribution of the MEFV gene mutation in our region with clinical findings

Familial Mediterranean Fever (FMF), which is an autosomal recessive disease characterized by recurrent self-limiting fever, peritonitis, pleuritis, arthritis and erysipelas-like erythemas, has been common among ethnic groups such as Turkish, Armenian, Arabic and Jewish. The clinical presentation is caused by mutations in the MEFV gene encoding the Pyrin protein. In this study, we aimed to present a new mutation that has not been previously defined from the mutations in the MEFV gene which is responsible for the genetic pathology of familial Mediterranean fever and to evaluate the frequency of distribution of the MEFV gene mutation among different ethnic groups living in our region. In present retrospective study, a total of 2639 clinically suspected FMF patients who were referred to Hatay Mustafa Kemal University Hospital between 2010 and 2017 were recorded. MEFV gene mutations were observed using DNA sequence analysis. MEFV mutations were found in 2079 of the 2639 patients (78.7%) Among these patients 184 (6.97%) were homozygous, while 1365 (51.72%) were heterozygous. The most frequently observed mutation was R202Q (1319, 19.55%) followed by E148Q (n = 476, 7.05%), M694V (n = 439, 6.51%), V726A (n = 146, 2.16%) and M680I (n = 135, 2%). In a case clinically diagnosed as FMF, a new mutation called S145G (p. Ser145Gly, c.433A > G) was identified in exon 2 of the MEFV gene. Besides, addition of a new pathogenic MEFV variant to the literature, the relationship between the FMF clinic and homozygous form of R202Q, which was previously considered as a polymorphism, was highlighted.

Next-generation screening of a panel of genes associated with periodic fever syndromes in patients with Familial Mediterranean Fever and their clinical characteristics

Familial Mediterranean Fever (FMF) is a hereditary fever syndrome that primarily affects Mediterranean populations. For the study, total number of 182 patients with FMF disease were enrolled and screening of a panel of genes , called "fever panel" which comprises 17 genes, was performed. The most common mutations in MEFV gene were homozygous M694V missense mutation (4.3%) and R202Q missense mutation (4.9%). The most common heterozygous mutations were R202Q (26.5%), M694V (25.9%) and E148Q (11.9%). Compound heterozygous and homozygous mutations were also detected. Also, different types of mutations were identified in NOD2, CARD14, NLRP12, NLRP3, NLRP7, IL1RN, LPIN2, TNFRSF1A, MVK and PSTPIP1 genes. Two novel missense variations in the MEFV gene, Gln34Pro and Ile247Val, which have not been previously reported in the databases, were identified. Also, Thr91Ile missense variation in the NOD2 gene, Gly461Cys missense variation in NLRP3 and Tyr732Stop nonsense variation in LPIN2 were firstly identified. The results of the current study suggest that in addition to the MEFV gene which has an important roles in FMF, molecular screening of other genes related to other autoinflammatory diseases might provide support in suspected cases and provide detailed information about the course of the disease.

Rheumatic diseases in Syrian refugee children: a retrospective multicentric study in Turkey

Since the Syrian civil war in 2011, an estimated number of 3.6 million Syrian refugees crossed into Turkey, and almost half of them were children. The distribution of rheumatic diseases in Syrian refugee children is not known. The aim of this study was to describe the profile of rheumatic diseases in Syrian refugee children living in Turkey. The demographic data, clinical and laboratory findings, medications, complications and outcome results of Syrian refugee children who had visited Pediatric Rheumatology Departments of University of Health Science Kanuni Sultan Süleyman Research and Training Hospital, Ümraniye Research and Training Hospital, Şanlıurfa Research and Training Hospital, and Cengiz Gökçek Maternity and Gynecology Hospital between April 1, 2011, and September 1, 2019, were evaluated retrospectively. A total of 151 patients were included in the study. Among them, 51 patients had juvenile idiopathic arthritis (JIA), 49 had familial Mediterranean fever (FMF), 43 had vasculitis, and 8 had connective tissue diseases. Homozygous M694V mutation was the most common mutation among FMF patients. Oligoarticular JIA (41.2%) was the most frequent type of JIA, and enthesitis-related arthritis (ERA) (27.5%) was the second one. The frequency of systemic JIA was 11.8%. One patient with SLE died due to complicated meningitis. This is the first study evaluating the distribution of rheumatic diseases in Syrian refugee children. Clinical follow-up of rheumatologic diseases is difficult in Syrian refugees due to language barriers, social and cultural differences. Health care systems should be well organized to provide appropriate care to asylum seekers.

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.

Novel Deleterious nsSNPs within MEFV Gene that Could Be Used as Diagnostic Markers to Predict Hereditary Familial Mediterranean Fever: Using Bioinformatics Analysis

Background

Familial Mediterranean Fever (FMF) is the most common autoinflammatory disease (AID) affecting mainly the ethnic groups originating from Mediterranean basin. We aimed to identify the pathogenic SNPs in MEFV by computational analysis software.

Methods

We carried out in silico prediction of structural effect of each SNP using different bioinformatics tools to predict substitution influence on protein structure and function.

Result

23 novel mutations out of 857 nsSNPs are found to have deleterious effect on the MEFV structure and function.

Conclusion

This is the first in silico analysis of MEFV gene to prioritize SNPs for further genetic mapping studies. After using multiple bioinformatics tools to compare and rely on the results predicted, we found 23 novel mutations that may cause FMF disease and it could be used as diagnostic markers for Mediterranean basin populations.

Clinical and Demographic Evaluation According to MEFV Genes in Patients with Familial Mediterranean Fever

The present study examined the relationship between clinical findings and mutation analyses in children with Familial Mediterranean Fever (FMF) in the inner Black Sea region of Turkey. This retrospective, cross-sectional study included patients with FMF who were evaluated between 2007 and 2015. FMF was diagnosed according to the Tel Hashomer criteria. FMF mutations were analyzed using a Real-time PCR System (Roche Diagnostics, Mannheim, Germany), and patients were classified into three groups according to allele status. The most common symptom was abdominal pain (99%, n = 197). The most frequent mutations were M694V and R202Q. Chest pain was reported more often in patients homozygous for M694V (61.4%). Although fever, abdominal pain, and arthritis were more commonly observed with the M694V mutation, chest pain was the most common symptom in R202Q carriers (n = 10, 32.3%). Proteinuria was observed in 42 (21.2%) patients, frequently accompanied by the M694V mutation (28.6%). The most common mutations in children with FMF in Turkey were M694V and R202Q. Recurrent abdominal pain and arthritis/arthralgia were commonly observed in patients with M694V and R202Q mutations. Moreover, chest pain was commonly seen with the R202Q mutation. Thus, R202Q might be a disease-causing mutation in FMF patients.