MEFV mutations in Turkish patients suffering from Familial Mediterranean Fever

Investigation of the relationship between disease severity and development of amyloidosis and genetic mutation in FMF disease

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive genetic disease. Amyloidosis is the most important complication of FMF that determines the prognosis of the disease.

AIMS

In our study, we have investigated the relationship between the genetic mutations with the disease severity and the frequency of development of amyloidosis inpatients with FMF.

METHODS

A total of 148 patients with FMF were included this study. The relationship between disease activity score, clinical findings, response to treatment, and presence of amyloid and genetic mutations were evaluated.

RESULTS

One hundred forty-eight patients (80 women (54%), 68 men (46%)) were enrolled over 18 years of age. The mean age of the patients was 30.98 ± 11.18 (18-67) years. In our study, the most frequently seen mutations are M694V, M680I, R202Q, and E148Q, respectively. The most common genotype is M694V/M694V mutation and this mutation has been found in 37 patients (25%). In 25 patients, M694V heterozygous have been found (16.8%). The third frequent mutationis M694V/M680I/R202Q has been found in13 patients (8.7%). In 23 patients, amyloidosis has been developed. Ten patients with amyloidosis have M694V homozygous mutations (27%) and 5 patients with amyloidosis M694V heterozygous (20%) mutations. The both of the two patients who carry the homozygous E148Q mutations have developed amyloidosis.

CONCLUSIONS

In our study, the distribution of the frequency of mutations is consistent with other similar studies performed in Turkey. We found that patients with M694V mutation had a significantly higher rate of exacerbation, higher drug doses for treatment, and a close relationship with amyloidosis, as compared to patients with other mutations.

Spectrum of MEFV gene mutations in 4,256 familial Mediterranean fever patients from Iran: a comprehensive systematic review

Background

Familial Mediterranean fever (FMF), known as a disease with a high prevalence rate among Armenian, Turkish, Jewish, and Arab descent populations, occurs as a result of pathogenic variants in mediterranean fever (MEFV) gene. The aim of this study was to review the spectrum and frequency of MEFV gene mutations reported among Iranian FMF patients.

Methods

After performing a systematic review of the literature and implementation of inclusion and exclusion criteria, 16 articles published between 2004 and 2020, involving 4,256 Iranian FMF patients, were included.

Results

A total of 38 different MEFV gene mutations were identified. The most common mutations among Iranian FMF patients were: p.M694V (c.2080A > G) (20.27%), p.E148Q (c.442G > C) (10.27%), p.V726A (c.2177T > C) (8.24%), p.M680I (both c.2040G > C and c.2040G > A) (7.20%), p.R761H (c.2282G > A) (2.1%), and p.M694I (c.2082G > A) (2. 1%). The frequencies of these mutations were significantly different in different parts of the country.

Conclusions

The ranks and frequencies of p.M694V, p.E148Q, p.V726A, p.M680I, and p.M694I in our population were closer to those observed in the Mediterranean countries, especially in the Middle Eastern Arab populations. Although some comprehensive studies have been performed on Azeri Turkish patients living in northwestern Iran, studies in other areas, especially in eastern Iran, have been very limited. One reason for this observation could be due to the low frequency of FMF patients in those areas. Regardless of the reason for this, the exact spectrum and frequency of MEFV gene mutations in Iranian FMF patients remain unclear. Therefore, comprehensive future studies in different parts of the country are recommended.

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.

Investigation of MEFV gene polymorphisms (G138G and A165A) in adult patients with familial Mediterranean fever

AIM

Various mutations have been identified in the Mediterranean fever (MEFV) gene which is reported to be responsible from Familial Mediterranean fever (FMF). In our study, we aimed to determine the frequency of the MEFV mutations in our region and to investigate the impact of G138G (rs224224, c.414A>G) and A165A (rs224223, c.495C>A) gene polymorphisms on the clinical findings of the disease.

METHODS

One hundred and sixteen patients diagnosed with FMF and 95 control subjects were included in this study. We used the DNA sequence analysis method to identify the most prevailing 10 mutations located in exon 2 and 10 of MEFV gene.

RESULTS

As a result of the MEFV mutation analysis, the most common mutation was the M694V mutation allele with a frequency rate of 41.8%. When the patients group and control group were compared in terms of frequency of both polymorphic alleles (G polymorphic allele, observed in G138G and the A polymorphic allele, observed in A165A), the variation was observed to be statistically significant (p<0.001). It was found that the MEFV mutation types have no relation with clinical findings and amyloidosis (p>0.05).

CONCLUSIONS

To our knowledge, our study is the first study in the Southern Marmara region that reports the frequency of MEFV mutations. Our findings imply that the polymorphisms of G138G and A165A may have an impact on progress of the disease. We think that more studies, having higher number of cases and investigating the polymorphisms of MEFV gene, are needed.

Is Turkish MEFV Mutations Spectrum Different Among Regions?

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive inherited inflammatory disease. The gene responsible for the disease, called MEFV, encodes a protein called pyrin or marenostrin. According to recent data, MEFV mutations are not the only cause of FMF, but genetic analysis of MEFV gene is needed for confirming the diagnosis of FMF. In the present study, we aimed to evaluate the molecular testing results of MEFV mutations.

METHODS

Molecular testing results of 1,435 patients were retrospectively evaluated over the last 4 years. These patients were identified as having FMF clinical symptoms. Patients were tested for 12 common mutations in the MEFV gene using a strip assay technique.

RESULTS

From all 1,435 patients, MEFV mutations were found in 776 patients (54.08%) and 659 patients (45.92%) did not carry any mutations. Patients with mutations were classified as homozygotes (n = 148), compound heterozygotes (n = 197), heterozygous (n = 427), and complex genotypes (n = 4, patients with three mutations). Allelic frequencies for the four most common mutations in the mutation-positive groups were 48.79% (M694V), 14.86% (M680I G/C), 13.70% (E148Q), and 12.35% (V726A). The remaining alleles (10.3%) showed rare mutations that were R761H, P369S, A744S, K695R, F479L, and M694I. No patient showed a I692del mutation that is sometimes evident in other Mediterranean populations.

CONCLUSION

It was found that the most common four mutations (M694V, M680I [G/C], E148Q, V726A) were similar to those previously reported from different regions of Turkey and this study might add some knowledge to the mutational spectrum data on FMF.

Relationship between clinical findings and genetic mutations in patients with familial Mediterranean fever

BACKGROUND

Familial Mediterranean fever (FMF) is one of the most frequent genetic diseases encountered in the Mediterranean region. We aimed to investigate the correlation between genetic mutations and the clinical findings in 562 patients with FMF.

METHODS

In this retrospective cross-sectional study conducted with patients' files between 2006, and 2013, reverse hybridization assay for MEFV gene mutations was used and the 12 most frequent mutations were screened. Mutation types and clinical findings were compared with variance analysis.

RESULTS

The mean age was 6.9 ± 3.4 years (range, 1.8-11.6 years). The most common symptom was fever (97.3%). Thirty-four of the patients (6.04%) were admitted with periodic fever only. Of these patients, M694V was the most common mutation type (73.5%). The percentage of the patients predominantly presenting with recurrent abdominal pain was 77.78% and the most frequent mutations were M694V and E148Q. The rate of arthritis and arthralgia was significantly higher in patients with M694V and E148Q mutations. Chest pain was reported more often in patients homozygous for M694V (61.4%). Pericardial effusion was documented in the echocardiography of 10.9% of the 229 children with chest pain. Some patients had both FMF and Henoch Schönlein purpura (HSP), and were more likely to harbor either homozygote M694V or E148Q mutations. The frequency of episodes was higher in patients with homozygous M694V mutations (number of attacks = 4.4 ± 1.6/month). Proteinuria was detected in 106 patients of cases (29.2%), at an average of 854 ± 145 mg/L. Most of the patients with proteinuria and elevated serum amyloid-A had homozygous M694V mutation.

CONCLUSION

The most common mutation in children in Turkey with FMF is the M694V mutation. Recurrent abdominal pain, arthritis or arthralgia, chest pain, and pericarditis were commonly seen in patients with M694V and E148Q mutations.

Familial Mediterranean Fever in Iran: A Report from FMF Registration Center

Background. Familial Mediterranean fever (FMF) is a periodic AR autoinflammatory disorder. This comprehensive study describes FMF in Iran as a country near Mediterranean area. Materials and Methods. From the country FMF registration center 403 patients according to Tel-Hashomer criteria enrolled this study, 239 patients had MEFV gene mutations analyses. Data, if needed, was analyzed by SPSS v20. Results. 175 patients (43.4%) were female and 228 patients (56.6%) were male. The mean age was 21.3 years. Abdominal pain was in 93.3% patients and 88.1% had fever. Abdominal pain was the main complaint of patients in (49.6%). The mean interval between attacks was 36.5 ± 29.6 days and the mean duration of every episodes was 43.3 ± 34.5 hours. 15.1% of patients had positive family history and 12.7% had previous surgery; in 52.3% of patients delay in diagnosis was more than three years. 12 common MEFV gene mutations were analyzed, 21.33% were without mutations, 39.7% had compound heterozygote, 25.52% showed heterozygous, and 13.38% showed homozygous results. The most common compound genotype was M694V-V726A (% 10.46) and in alleles M694V (% 20.9) and V726A (% 12.7) were the most frequent mutations, respectively. Conclusion. M694V was the most common mutation, and the most common compound genotype was M694V-V726A. Our genotype results are similar to Arabs and in some way to Armenians, erysipelas-like skin lesions are not common in this area, and clinical criteria are the preferred methods in diagnosis of FMF.

The inflammasomes and autoinflammatory syndromes

Inflammation, a vital response of the immune system to infection and damage to tissues, can be initiated by various germline-encoded innate immune-signaling receptors. Among these, the inflammasomes are critical for activation of the potent proinflammatory interleukin-1 cytokine family. Additionally, inflammasomes can trigger and maintain inflammatory responses aimed toward excess nutrients and the numerous danger signals that appear in a variety of chronic inflammatory diseases. We discuss our understanding of how inflammasomes assemble to trigger caspase-1 activation and subsequent cytokine release, describe how genetic mutations in inflammasome-related genes lead to autoinflammatory syndromes, and review the contribution of inflammasome activation to various pathologies arising from metabolic dysfunction. Insights into the mechanisms that govern inflammasome activation will help in the development of novel therapeutic strategies, not only for managing genetic diseases associated with overactive inflammasomes, but also for treating common metabolic diseases for which effective therapies are currently lacking.

Familial Mediterranean fever gene mutations as a risk factor for early coronary artery disease

OBJECTIVE

Cardiovascular diseases (CVD) are very common in the general population. Atherosclerosis is the main pathogenesis. Familial Mediterranean fever (FMF) is an autosomal recessive disease. The gene causing FMF, designated MEFV, encodes a protein called pyrin or marenostrin that is expressed mainly in myeloid bone marrow precursors, neutrophils and monocytes. We herein aimed to determine the prevalence of MEFV mutations (all exon 2, 10 mutations) in patients with early coronary heart disease (early CHD) and coronary heart disease (CHD) with multiple risk factors and among the healthy subjects as controls.

METHODS

A total of 197 patients and 119 healthy subjects were recruited and enrolled into three groups in terms of inclusion criteria. Ninety-one patients diagnosed with early CHD enrolled into group one (men < 45 years of age, women < 40 years of age), 106 patients with CHD (men > 50 years of age) to group two and 119 healthy controls enrolled into group three. None of patients was diagnosed with FMF. The diagnosis of CHD was established on electrocardiographic changes, echocardiography and coronary angiography.

RESULTS

Thirty-eight patients (41.8%) with early CHD, 17 patients (16%) with CHD and 24 healthy controls (20.2%) carried at least one mutated MEFV allele. Young patients with CHD have different risk factor profiles, clinical presentations and prognoses than older patients. Young patients with CHD usually have multiple risk factors.

CONCLUSION

This study suggests that MEFV mutations in early CHD patients had significantly increased in contrast to CHD patients and healthy controls.

The frequency of Familial Mediterranean fever gene mutations and genotypes at Kirikkale and comparison with the mean of regional MEFV mutation frequency of Turkey

In this study we have retrospectively analysed the mutation spectrum of the 351 Familial Mediterranean fever patients referred to Kırıkkale University Faculty of Medicine, Department of Medical Genetics Laboratory over a period of 5 years and compared them with Turkey's mean. We have found 11 different mutations, including rare mutations such as F479L, K695R, M680I(G/A) and 45 different genotypes showing the heterogeneity of MEFV mutations in Central Anatolia. The most three prevalent mutations were M694V (14.8%), E148Q (7.1%) and M680I(G/C) (4.1%) in accordance with the literature. We have also investigated R202Q in our routine molecular diagnosis. Mutation causing R202Q (c.605G > A) change was described as a frequent polymorphism and G allele was found in linkage disequilibrium (LD) with M694V. There are limited number of studies investigating R202Q, some of them implicate that its homozygote state is disease causing. We showed the high frequency of R202Q (23.7%) with and without M694V in all the groups analysed and its high LD rate with M694V in the diagnosed group. Our study is reflecting the mutational heterogeneity of MEFV and summarize mutational spectrum of Turkey's geographical regions and overall Turkey.

Application of the new pediatric criteria and Tel Hashomer criteria in heterozygous patients with clinical features of FMF

Recently, a new set of criteria was established for the diagnosis of familial Mediterranean fever (FMF) in childhood. The aim of this study is to validate the new criteria set among heterozygous patients with clinical features of FMF. The study group consisted of FMF patients, who had a mutation at a single allele, who were followed in four pediatric nephrology-rheumatology centers in Turkey. Patients were evaluated by the new criteria set and also by the Tel Hashomer criteria. According to the new criteria, the diagnosis of FMF was established by the presence of two or more of five criteria (fever, abdominal pain, chest pain, arthritis, family history of FMF). The study group consisted of 110 FMF (54 male, 56 female) patients. Majority of the patients had heterozygous pM694V mutation (65%). The sensitivity of the new criteria set and that of the Tel Hashomer criteria in our study group were found to be 93% and 100%, respectively. In conclusion, this study designates that sensitivity of the new criteria set is also high in patients who had a mutation at a single allele.

Common MEFV mutation analysis in 36 Iranian patients with familial Mediterranean fever: clinical and demographic significance

The aim of our study was to determine the spectrum of the 12 most common familial Mediterranean fever gene (MEFV) mutations in Iranian patients with heterogeneous ethnicity, using the familial Mediterranean fever (FMF) strip assay test. A total of 36 patients were diagnosed according to established clinical criteria. Genomic DNA from all patients was tested for 12 common mutations located in exon 2 (E148Q), 3 (P369S), 5 (F479L), 10 [M680I (G>C), M680I (G>A), I692del, M694V, M694I, K695R, V726A, A744S, R761H], respectively, using the FMF strip assay test. Of the 35 patients with mutations, ten were homozygote, 20 were compound heterozygote, and five were heterozygote. The most frequent genotype was M680I/M680I (6 patients, 16.7%). The most frequent mutation was M680I, followed by M694V, and V726A. The FMF strip assay test for common these 12 mutations was positive in 90.6% of alleles in this study, indicating that it appears to be an effective method for FMF mutation screening in Iranian patients.

Unresponsiveness to colchicine therapy in patients with familial Mediterranean fever homozygous for the M694V mutation

OBJECTIVE

More than 50 disease-associated mutations of the Mediterranean fever gene (MEFV) have been identified in familial Mediterranean fever (FMF), some of which were shown to have different clinical, diagnostic, prognostic, and therapeutic implications. The aim of our study was to define the frequency of mutation type, genotype-phenotype correlation, and response to colchicine treatment in patients with FMF.

METHODS

This study included 222 pediatric FMF patients. All patients were investigated for 6 MEFV mutations. Then patients were divided into 3 groups according to the presence of M694V mutation on both of the alleles (homozygotes), on only 1 allele (heterozygotes), and on none of the alleles, and compared according to their phenotypic characteristics and response to treatment. M694V/M694V was denoted Group A, M694V/Other Group B, and Other/Other, Group C.

RESULTS

Complete colchicine response was significantly lower while the rate of unresponsiveness was significantly higher in Group A compared to Groups B and C (p = 0.031, p < 0.001 and p = 0.005, p = 0.029, respectively). No differences except proteinuria were found between the phenotypic features of 3 groups. Group C had the lowest rate of proteinuria development (p = 0.024). All the amyloidosis patients were in Group A.

CONCLUSION

Our results indicate that the M694V/M694V mutation is associated with lower response to colchicine treatment. Therefore, patients homozygous for M694V/M694V may be carrying an increased risk for development of amyloidosis.

MEFV mutations in patients with Familial Mediterranean Fever from the Aegean region of Turkey

Familial Mediterranean Fever (FMF) which is frequently present in Mediterranean populations is caused by mutations in the MEFV gene. According to recent data, MEFV mutations are not the only cause of FMF, but these are major genetic determinants which cause FMF. It has also been suggested that there may be a number of other genes causing FMF. The MEFV gene is located at 16p13.3 and encodes a protein, pyrin/marenostrin. More than 70 disease associated mutations and totally 186 mutations and polymorphisms have been defined in affected individuals. We have retrospectively evaluated the molecular test results of 1,201 patients identified as having FMF clinical symptoms referred to the Molecular Genetics Laboratory of the Department of Medical Genetics, Faculty of Medicine, Ege University, Izmir/Turkey over the last 4 years. Patients were tested for 12 common mutations in the MEFV gene using a strip assay method (Innogenetics, Belgium). Out of the 1,201 patients tested (2,402 chromosomes) in the Aegean region in Turkey, 654 (54.45%) did not carry any mutations, among the 547 (45.55%) patients with mutations 246 patients were either homozygous (101) or compound heterozygous (145), 296 carried only one detected mutation, and five patients had three mutations. Allelic frequencies for the four most common mutations in the mutation positive groups were 47.60% (M694V), 16.75% (E148Q), 12.95% (V726A), 11.94% (M680I G/C).The remaining alleles (10.76%) showed rare mutations which were R761H, P369S, A744S, K695R, F479L, M694I. When the frequencies of mutations detected in our group were compared to the frequencies reported in the other regions of Turkey, an increase in V726A mutation frequency was observed. No patient showed a I692del mutation which is sometimes evident in other Mediterranean populations.

A new set of criteria for the diagnosis of familial Mediterranean fever in childhood

OBJECTIVES

Several sets of criteria mainly for adults have been proposed for the diagnosis of FMF. The aim of the present study is to validate the most widely used diagnostic 'Tel Hashomer' criteria in children and to establish a new set of criteria for use in childhood.

METHODS

The study group consisted of 170 recently diagnosed FMF patients who had mutations at both alleles. They were interviewed about the presence of 35 features and manifestations of FMF at the time of diagnosis. Controls were consecutive patients without FMF (n = 141) who had episodes of fever and clinical features mimicking that of FMF. The diagnostic performance of the candidate features was assessed by multiple logistic regression analysis.

RESULTS

The sensitivity and specificity of Tel Hashomer criteria in our study group were 98.8 and 54.6%, respectively. The multiple logistic regression analysis showed that 5 (fever, abdominal pain, chest pain, arthritis and family history of FMF) of the 35 candidate criteria discriminate FMF from controls with a sensitivity and specificity of 88.8 and 92.2%, respectively. The presence of two or more of these five criteria diagnosed FMF with a sensitivity of 86.5% and a specificity of 93.6%.

CONCLUSION

It was demonstrated that although the Tel Hashomer criteria were successful in diagnosing the FMF patients in childhood, its specificity was definitely low in children. The new set of criteria has a high sensitivity and specificity for the diagnosis of FMF and is practical to use on an everyday basis.

The clinical and genetical features of 124 children with Familial Mediterranean fever: experience of a single tertiary center

The aim of the present study was to evaluate the clinical features of childhood-onset Familial Mediterranean fever (FMF) patients and to assess the phenotype-genotype correlation. The study included patients with childhood-onset FMF that followed up over a period of 18 years in the Division of Pediatric Allergy and Immunology clinic. Twelve MEFV mutations were investigated in all patients. The patients were classified into four groups according to mutations: 1, M694V homozygote; 2, M694V heterozygote; 3, compound heterozygote for M694V; and 4, other-other gene mutation group. The following parameters were evaluated: gender, age of onset, age at diagnosis, time interval between disease onset and diagnosis, fever, abdominal pain, chest pain, arthralgia, arthritis, myalgia, vomiting, diarrhea, constipation, headache, erysipela-like erythema, protracted febrile myalgia, splenomegaly, hepatomegaly, consanguinity, number of attacks before and after treatment, severity score, response to colchicine treatment. Of the 124 patients included in the study, 105 had at least one MEFV gene mutation. M694V homozygosity was the most common mutation, followed by M694V heterozygotes and M694V-M680I compound heterozygotes. Severity score was found significantly higher in patients with M694V homozygote and compound heterozygote for M694V compared with other groups. The data supported the findings in literature that FMF patients with M694V homozygote and compound heterozygote for M694V gene mutations experience a more severe clinical course.

Common MEFV mutation analysis in Iranian Azeri Turkish patients with familial Mediterranean fever

OBJECTIVES

To identify the frequency and distribution of familial Mediterranean fever (FMF) gene (MEFV) mutations among Azeri Turkish patients from northwestern Iran.

METHODS

One hundred ninety unrelated patients were referred by specialists to the Molecular-Medical Genetic Center of Tabriz. A clinical diagnosis of FMF was made according to published criteria. Mutation screening of the MEFV gene was performed for the 5 most commonly known mutations, namely M694V, V726A, M680I, M694I, and E148Q, by using amplification refractory mutation system for the first 4 and by polymerase chain reaction restriction-digestion testing for E148Q. These methods may also be used as a screening tool within affected families.

RESULTS

Of the unrelated patients investigated, 120 (63%) had 1 or 2 mutations. Of those with mutations, 41 were homozygous, 37 were compound heterozygous, and 42 had only 1 identifiable mutation. Of the studied alleles, the most frequent mutation was M694V (28%), followed by V726A (9%), E148Q (7%), M680I (7%), and M694I (1%) mutations.

CONCLUSIONS

Our results indicate that the common Mediterranean mutations are frequent in the Azeri Turkish FMF patients but with some differences in the frequency of individual mutations. The high frequency of E148Q in Azeri Turks compared with Mediterranean ethnic groups is rather interesting. The results open the way for further investigations on patients diagnosed as having FMF and in whom no mutations or only 1 mutated allele were found.

A very frequent mutation and remarkable association of R761H with M694V mutations in Turkish familial Mediterranean fever patients

Familial Mediterranean fever (FMF) is an autosomal-recessive disease. It is characterized by recurring fever, abdominal pain, and serositis. The Mediterranean fever (MEFV) gene is localized on 16p13.3 and more than 35 mutations have been described to date. There are some differences in the gene mutations of FMF in the various ethnic groups. The aim of this study is to determine the frequency of the mutations which has been reported comparatively rare, to define the most effective mutation set, and to select the most suitable DNA analysis system for Turkish FMF patients. Mutations in 330 Turkish FMF patients with typical phenotypes from various regions of Turkey were evaluated for the research purposes. These patients were analyzed for six MEFV gene mutations by the NanoChip Molecular Genetics Workstation. The most frequent mutation was M694V, identified in 50.00% of the alleles examined; M680I followed with 14.10% and V726A--9.70%. Consequently, we determined that R761H (n = 23; 3.48%) was the most frequent rare mutations in Turkish FMF patients. Frequency of the rare mutations were R761H (3.48%), E148Q (1.36%), and M694I (1.21%). All of these mutations were in the compound heterozygote state. Our study showed that R761H mutations were higher than it has been reported in literature until now and were mainly associated with M694V. We suggest that mutation R761H should be included in the mutation scanning analysis researches or considered if the patient has M694V/? mutation especially in Turkish FMF patients. Larger serial studies need to be done to investigate the rate and coexistence of these mutations.

The evaluation of carotid intima-media thickness in children with familial Mediterranean fever

The aim is to investigate whether pediatric familial Mediterranean fever (FMF) patients have an increased risk of premature atherosclerosis and to determine the possible strength of association between atherosclerosis and Mediterranean fever (MEFV) gene mutation gene type. Demographic characteristics and MEFV mutations were defined in 49 children diagnosed with FMF (26 female, 23 male; mean age, 10.71 +/- 3.69 years). Twenty-six age-, sex-, and body-mass-index-matched healthy children constituted the control group. We evaluated the blood counts and acute-phase proteins during attack-free periods. Mean C-reactive protein (CRP), serum amyloid-A (SAA), homocysteine (Hcy), lipoprotein-a (Lp-a), and common carotid artery intima-media thickness (CCA-IMT) were 10.75 +/- 15.29 vs 4.03 +/- 1.20, 23.22 +/- 41.94 vs 3.53 +/- 1.04, 10.36 +/- 3.36 vs 8.64 +/- 3.15, 20.84 +/- 23.89 vs 8.56 +/- 7.48, and 0.038 +/- 0.007 vs 0.032 +/- 0.004, respectively, and significantly higher than the mean values of control group (p < 0.05). However, no correlation was found between CCA-IMT and CRP, SAA, Hcy, and Lp-a. Twenty-nine patients had M694V mutation, and 13 patients had other mutations. There was no correlation between CCA-IMT and MEFV mutation subgroups. In conclusion, because of the nature of the disease, FMF patients should be considered to have an increased risk of early vascular alteration and atherosclerosis. For this reason, CCA-IMT measurement can be recommended as a noninvasive and early diagnostic method.

Population genetics of familial Mediterranean fever: a review

In this review, some principal population genetic features of familial Mediterranean fever (FMF) are considered. These relate to the time and the place of founder mutations' origins, the role of ancient migrations and contacts between populations in the spatial spreading of the disorder, the influence of environmental factors and cultural traditions on the rate of FMF incidence, and possible selective advantage in carriers of FMF causing gene (MEFV) mutations.

MEFV Mutations in Tunisian Patients Suffering from Familial Mediterranean Fever

OBJECTIVES

To identify the frequency and distribution of familial Mediterranean fever (FMF) gene (MEFV) mutations in Tunisian patients.

PATIENTS AND METHODS

This study was performed in the Genetic Department of Tunis University Hospital. A clinical diagnosis of FMF was made according to published criteria. Mutation screening of the MEFV gene was performed in the Human Genetic Laboratory of the "Faculté de Medecine de Tunis" for 8 mutations including the 5 most common known mutations M694V, V726A, M694l, M680l, and E148Q. The tests performed were polymerase chain reaction (PCR) restriction-digestion for M694V, V726A, M680l, R761H, E148Q; amplification refractory mutation system for A744S, M694l; and PCR-electrophoresis assay for l692del.

RESULTS

Of the 139 unrelated patients investigated, 61 (44%) had 1 or 2 mutations. In 78 (56%) probands no mutation was identified: 28 patients were homozygous; 16 were compound-heterozygous; 2 had complex alleles; and 17 had only 1 identifiable mutation. Of the mutations, M680l, M694V, M694l, V726A, A744S, R761H, l692DEL, and E148Q accounted for 32, 27, 13, 5, 3, 1, 1, and 18%, respectively.

CONCLUSION

The profile of the MEFV gene mutations in the Tunisian population is concordant with other Arab populations but with some differences. M680l is the most common mutation, while V726A, the commonest mutation among Arabs, is rare in our population.

Familial Mediterranean fever

Familial Mediterranean fever (FMF) is the most frequent hereditary inflammatory disease characterized by self-limited recurrent attacks of fever and serositis. It is transmitted in an autosomal recessive pattern and affects certain ethnic groups mainly Jews, Turks, Arabs, and Armenians. FMF is caused by mutations in MEFV gene, which encodes pyrin. This protein is expressed mainly in myeloid/monocytic cells and modulates IL-1beta processing, NF-kappaB activation, and apoptosis. A mutated pyrin probably results in uncontrolled inflammation. The most devastating complication of FMF is amyloidosis, leading to chronic renal failure. M694V homozygocity, male gender and the alpha/alpha genotype of serum amyloid A1 gene are the currently established risk factors for development of amyloidosis. Daily colchicine is the mainstay of the therapy for the disease, resulting in complete remission or marked reduction in the frequency and duration of attacks in most patients. It is also effective in preventing and arresting renal amyloidosis.

Familial Mediterranean fever

Familial Mediterranean fever (FMF) is the most frequent hereditary inflammatory disease characterized by self-limited recurrent attacks of fever and serositis. It is transmitted in an autosomal recessive pattern and affects certain ethnic groups mainly Jews, Turks, Arabs, and Armenians. FMF is caused by mutations in MEFV gene, which encodes pyrin. This protein is expressed mainly in myeloid/monocytic cells and modulates IL-1beta processing, NF-kappaB activation, and apoptosis. A mutated pyrin probably results in uncontrolled inflammation. The most devastating complication of FMF is amyloidosis, leading to chronic renal failure. M694V homozygocity, male gender and the alpha/alpha genotype of serum amyloid A1 gene are the currently established risk factors for development of amyloidosis. Daily colchicine is the mainstay of the therapy for the disease, resulting in complete remission or marked reduction in the frequency and duration of attacks in most patients. It is also effective in preventing and arresting renal amyloidosis.

Regular abdominal pain and fever in each menstruation onset: an unusual menses-associated familial Mediterrenean fever attacks and a favor result on colchicine treatment

We present a 38-year-old woman suffering from regular abdominal pain and fever only in each menstruation onset for 7 years. The clinical symptoms, along with inflammatory findings during painful attacks, the beneficial effect of colchicine and genetic mutation (M694 V and M680I) supported the diagnosis of familial Mediterranean fever (FMF). A literature review indicated that FMF attacks occurring only during menstruation are rarely seen. This clinical picture may be confused with gynecological disorders especially in the people of Mediterranean origin.

Sacroiliitis in familial Mediterranean fever and seronegative spondyloarthropathy: importance of differential diagnosis

Familial Mediterranean fever (FMF) is a multisystemic autosomal recessive disease, occasionally accompanied by sacroiliitis. Transient and non-erosive arthritis of the large joints is the most frequent articular involvement. Amyloidosis is also the most significant complication of FMF, leading to end stage renal disease. Here we present three cases of FMF with sacroiliitis and review the literature for spinal arthritic involvement of FMF. All cases were referred to our clinic with a diagnosis of seronegative spondyloarthropathy and with low back pain sourced by sacroiliitis. They also had homozygous M694V gene mutations and negative HLA B27 antigens. Molecular analysis of the gene mutation is recommended during the evaluation of uncertain cases in order to clarify diagnostic discrimination. We suggest that FMF with sacroiliitis, which is rare in rheumatological practice, should be considered in the differential diagnosis of seronegative spondyloarthropathy or other rheumatologic diseases causing spinal involvement.

The KBG syndrome: confirmation of autosomal dominant inheritance and further delineation of the phenotype

We report on a Turkish family in which the father and his two sons were diagnosed as having the KBG syndrome. Large upper central incisors were the diagnostic finding in all three patients along with mental retardation, cryptorchidism, skeletal abnormalities, and short stature. Our report clearly confirms that the inheritance is autosomal dominant in KBG syndrome, although a high male to female ratio has been observed in published cases.

Familial Mediterranean fever (FMF) in Turkey: results of a nationwide multicenter study

Familial Mediterranean fever (FMF) is an autosomal recessive disease that is prevalent among eastern Mediterranean populations, mainly non-Ashkenazi Jews, Armenians, Turks, and Arabs. Since a large proportion of all the FMF patients in the world live in Turkey, the Turkish FMF Study Group (FMF-TR) was founded to develop a patient registry database and analyze demographic, clinical, and genetic features. The cohort was composed of 2838 patients (mean age, 23.0 +/- 13.33 yr; range, 2-87 yr), with a male:female ratio of 1.2:1. There was a mean period of 6.9 +/- 7.65 years from disease onset to diagnosis; the period was about 2 years shorter for each decade since 1981. Ninety-four percent of patients were living in the central-western parts of the country; however, their familial origins (70% from the central-eastern and Black Sea regions) reflected not only the ongoing east to west migration, but also the historical roots of FMF in Turkey. Patients' clinical features included peritonitis (93.7%), fever (92.5%), arthritis (47.4%), pleuritis (31.2%), myalgia (39.6%), and erysipelas-like erythema (20.9%). Arthritis, arthralgia, myalgia, and erysipelas-like erythema were significantly more frequent (p < 0.001) among patients with disease onset before the age of 18 years. Genetic analysis of 1090 patients revealed that M694V was the most frequent mutation (51.4%), followed by M680I (14.4%) and V726A (8.6%). Patients with the M694V/M694V genotype were found to have an earlier age of onset and higher frequencies of arthritis and arthralgia compared with the other groups (both p < 0.001). In contrast to other reported studies, there was no correlation between amyloidosis and M694V homozygosity in this cohort. However, amyloidosis was still remarkably frequent in our patients (12.9%), and it was prevalent (27.8%) even among the 18 patients with a disease onset after age 40 years. Twenty-two patients (0.8%) had nonamyloid glomerular diseases. The high prevalence of vasculitides (0.9% for polyarteritis nodosa and 2.7% for Henoch-Schonlein purpura) and high frequency of pericarditis (1.4%) were striking findings in the cohort. Phenotype II cases (those patients with amyloidosis as the presenting or only manifestation of disease) were rare (0.3% or less). There was a high rate of a past diagnosis of acute rheumatic fever, which suggested a possible misdiagnosis in children with FMF presenting with recurrent arthritis. To our knowledge, this is the largest series of patients with FMF reported from 1 country. We describe the features of the disease in the Turkish population and show that amyloidosis is still a substantial problem.

Familial Mediterranean fever among patients from Karabakh and the diagnostic value of MEFV gene analysis in all classically affected populations

OBJECTIVE

Familial Mediterranean fever (FMF) is an autosomal-recessive disorder that is common in Armenian, Turkish, Arab, and Sephardic Jewish populations. Its clinical diagnosis is one of exclusion, with the patients displaying nonspecific symptoms related to serosal inflammation. MEFV gene analysis has provided the first objective diagnostic criterion for FMF. However, in the absence of an identified mutation (NI/NI genotype), both the sensitivity of the molecular analyses and the involvement of the MEFV gene in FMF are called into question. The present study was designed to further evaluate the diagnostic value of MEFV analysis in another population of Mediterranean extraction.

METHODS

The MEFV gene was screened for mutations in 50 patients living in Karabakh (near Armenia) who fulfilled the established criteria for FMF. In addition, we analyzed published series of patients from the above-mentioned at-risk populations.

RESULTS

The mutation spectrum in Karabakhian patients, which consisted of only 6 mutations (with 26% of NI alleles), differed from that reported in Armenian patients. Strikingly, among patients from Karabakh and among all classically affected populations, the distribution of genotypes differed dramatically from Hardy-Weinberg equilibrium (P = 0.0016 and P < 0.00001, respectively). These results, combined with other population genetics-based data, revealed the existence of an FMF-like condition that, depending on the patients' ancestry, was shown to affect 85-99% of those with the NI/NI genotype.

CONCLUSION

These data illuminate the meaning of negative results of MEFV analyses and show that in all populations evaluated, most patients with the NI/NI genotype had disease that mimicked FMF and was unrelated to the MEFV gene. Our findings also demonstrate the high sensitivity of a search for very few mutations in order to perform a molecular diagnosis of MEFV-related FMF.

Serum amyloid A1 and tumor necrosis factor-alpha alleles in Turkish familial Mediterranean fever patients with and without amyloidosis

The major complication of familial Mediterranean fever (FMF) is AA amyloidosis. The influence of FMF gene (MEFV) mutations and/or unknown environmental factors and other genetic modifiers are likely to affect the phenotypic variations of the disease and the development of amyloidosis. Serum amyloid A is a serum precursor of AA amyloid that is induced by inflammatory cytokines including TNF-alpha. Our analysis of SAA1.1 frequency in Turkish FMF-amyloidosis patients, revealed a higher frequency compared to non FMF-amyloidosis patients but the difference was not significant. On the other hand, the distribution of SAA1.1 homozygosity among FMF-amyloidosis patients was 55.5% compared to FMF-non-amyloidosis patients (30.8%) which was statistically significant revealing a 2.5 fold risk for the occurrence of amyloidosis. There was no significant difference between the controls and FMF patients with and without amyloidosis for the TNF-alpha-308 G-A allele. It is worth noting that all TNF-alpha-308 G-A carriers (n = 6) in FMF-amyloidosis group have SAA1.1 homozygosity compared to 2/11 in FMF-non-amyloidosis group. Further evaluation of these polymorphisms may have importance and need further study.

Familial Mediterranean fever (FMF) mutations occur frequently in the Greek-Cypriot population of Cyprus

Familial Mediterranean Fever (FMF) is an autosomal recessive disease of high prevalence within Mediterranean countries and particularly common in four ethnic populations: Arabs, non-Ashkenazi Jews, Armenians, and Turks. The responsible gene MEFV has been assigned to chromosome 16p13.3. Our aim was to establish the frequencies of the most common mutations in Greek-Cypriots. We found that 1 in 25 is a carrier of one of three mutations. V726A, M694V, and F479L. In 68 Grek-Cypriot FMF chromosomes analyzed, we found V726A (25%), F479L (20.6%), M694V (17.6%), and others (36.8%). Mutation F479L, relatively common in this population, is very rare elsewhere. Our study indicates that FMF is not a rare condition in Cyprus and that, because of the significant morbidity associated with this disorder, which is often diagnosed only after unnecessary surgeries, a newborn screening program to detect affected in this population may be warranted.

The significance of paired MEFV mutations in individuals without symptoms of familial Mediterranean fever

The majority of patients with familial Mediterranean fever (FMF) have identifiable mutations in both alleles of the MEFV gene, while some individuals with paired MEFV mutations do not have clinical symptoms of the disease. During family studies we identified nine such individuals from six kindreds, most of whom either subsequently developed FMF or had other clinically significant inflammatory disease; one case benefiting substantially from colchicine therapy. Four individuals remained asymptomatic. Two further asymptomatic subjects with paired MEFV mutations were identified among 49 healthy controls from western Turkey, of whom a further 18.4 per cent were simple heterozygotes. This carrier rate was higher than would be expected from prevalence of FMF in this region, suggesting that penetrance of paired recognised pathogenic MEFV mutations may frequently be incomplete. MEFV genotyping results must be interpreted with due caution, and follow-up of apparently asymptomatic subjects with paired mutations is advisable.

Two novel mutations R653H and E230K in the Mediterranean fever gene associated with disease

Familial Mediterranean fever (FMF) is an autosomal recessive disorder caused by mutations in the Mediterranean fever gene (MEFV). We describe two novel missense mutations in MEFV, R653H and E230K. Both were found in compound heterozygosity with the mutation M694V in single Turkish patients with clinical syndromes characteristic for FMF. DNA sequencing and PCR-RFLP typing of the families confirmed the mutations and verified recessive modes of inheritance.

The spectrum of Familial Mediterranean Fever (FMF) mutations

Familial Mediterranean Fever (FMF) is the prototype of a group of inherited inflammatory disorders. The gene (MEFV) responsible for this disease, comprises 10 exons and 781 codons. Twenty-nine mutations, most located in the last exon, have been identified so far. It is unclear whether all are true disease-causing mutations. Five founder mutations, V726A, M694V, M694I, M680I and E148Q account for 74% of FMF chromosomes from typical cases (Armenians, Arabs, Jews, and Turks). Rare mutations are preferentially found in populations not usually affected by FMF (eg Europeans not from the above ancestries). The various combinations of MEFV mutations define severe to mild genotypes. The trend is that genotypes including two mutations located within mutational 'hot-spots' (codons 680 or 694) of the gene are associated with severe phenotypes, whereas mild phenotypes are associated with some other mutations, E148Q being the mildest and least penetrant. Understanding the correlation between the FMF phenotype and genotype is further obscured by the existence of complex alleles, modifier loci, genetic heterogeneity and possible epigenetic factors. Additionally, mutations in the MEFV gene are thought to be involved in non FMF disorders. Carrier rates for FMF mutations may be as high as 1:3 in some populations, suggesting that the disease is underdiagnosed. This review update emphasises that both clinical and genetic features are to be taken into account for patient diagnosis, colchicine treatment and prognosis.

Episodic evolution of pyrin in primates: human mutations recapitulate ancestral amino acid states

Familial Mediterranean fever (FMF; MIM 249100) is an autosomal recessive disease characterized by recurrent attacks of fever with synovial, pleural or peritoneal inflammation. The disease is caused by mutations in the gene encoding the pyrin protein. Human population studies have revealed extremely high allele frequencies for several different pyrin mutations, leading to the conclusion that the mutant alleles confer a selective advantage. Here we examine the ret finger protein (rfp) domain (which contains most of the disease-causing mutations) of pyrin during primate evolution. Amino acids that cause human disease are often present as wild type in other species. This is true at positions 653 (a novel mutation), 680, 681, 726, 744 and 761. For several of these human mutations, the mutant represents the reappearance of an ancestral amino acid state. Examination of lineage-specific dN/dS ratios revealed a pattern consistent with the signature of episodic positive selection. Our data, together with previous human population studies, indicate that selective pressures may have caused functional evolution of pyrin in humans and other primates.