Familial Mediterranean fever (FMF) in Lebanon and Jordan: a population genetics study and report of three novel mutations

Concurrence of familial Mediterranean fever and Behçet's disease: a case report and review of the literature

BACKGROUND

Familial Mediterranean fever and Behçet's disease are distinct disorders that are prevalent in the Mediterranean and Middle Eastern populations. They are characterized by unprovoked inflammatory episodes caused by overexpression of proinflammatory cytokines. Although reported previously, the overlapping presentation of familial Mediterranean fever and Behçet's disease remains uncommon.

CASE PRESENTATION

A 46-year-old Lebanese-Canadian man who presented with recurrent oral and genital ulcers, polyarticular synovitis, ocular swelling, recurrent infections, and fevers was later found to have heterozygous mutations of pathogenic MEFV c.2080A > G (p. Met 694Val) and c.2082G > A (p.Met694IIe) genes indicating familial Mediterranean fever. He was treated with prednisone, colchicine, and azathioprine, with inadequate symptoms control. Treatment was complicated by recurrent infections.

CONCLUSIONS

Our case contributes to the growing literature demonstrating the presentation of predominantly Behçet's disease-like features in the setting of diagnosis of familial Mediterranean fever. These findings emphasize that clinicians should be aware that patients with familial Mediterranean fever may present with Behçet's disease-like clinical manifestations.

Familial Mediterranean Fever in Spain: Time Trend and Spatial Distribution of the Hospitalizations

Familial Mediterranean Fever (FMF) is a rare, hereditary, auto-inflammatory disease. The aims of this study were to explore the time trend and geographical distribution of hospitalizations in Spain from 2008 to 2015. We identified hospitalizations of FMF from the Spanish Minimum Basic Data Set at hospital discharge, using ICD-9-CM code 277.31. Age-specific and age-adjusted hospitalization rates were calculated. The time trend and the average percentage change were analyzed using Joinpoint regression. Standardized morbidity ratios were calculated and mapped by province. A total of 960 FMF-related hospitalizations (52% men) were identified across the period 2008-2015, with an increase in hospitalizations of 4.9% per year being detected (p < 0.05). The risk of hospitalization was higher than expected for the national total (SMR > 1) in 13 provinces (5 in the Mediterranean area), and lower (SMR < 1) in 14 provinces (3 in the Mediterranean area). There was an increase in hospitalizations of patients with FMF in Spain throughout the study period, with a risk of hospitalization that was higher, though not exclusively so, in provinces along the Mediterranean coast. These findings contribute to the visibility of FMF and provide useful information for health planning. Further research should take into account new population-based information, in order to continue monitoring this disease.

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.

Contribution of Arab Countries to Familial Mediterranean Fever Research: a PubMed-based bibliometric analysis

Familial Mediterranean Fever (FMF) is an inherited autoinflammatory disease. One of the feared complications of FMF, amyloidosis is often correlated with an increased mortality rate. The severity of the disease is linked with different mutations in the MEFV gene that may favor different outcomes (amyloidosis, Bechet's disease…). Although several countries worldwide contribute remarkably to research related to FMF, Arab countries make up only a small part of this contribution. This study aims to estimate numerically the contribution of the Arab world to research conducted on FMF. PubMed is used to quantitate the number of FMF-related articles published by each Arab country from 2004 till 2019. The retrieved numbers are normalized with respect to each country's average population and average Gross Domestic Product (GDP) and are also compared to those of some non-Arab countries having high FMF prevalence. In comparison with some non-Arab countries, the Arab world has a minor contribution of 3.80% to the total FMF-related publications, faced by 24.93% solely by Turkey. Out of total research done by Arab countries, FMF-related articles constitute no more than 0.133%. When normalized against the average population, Tunisia ranks first, followed by Lebanon. Similarly, normalizing the retrieved numbers of articles against average GDP shows that Tunisia and Lebanon come first and second, respectively. Only 8 Arab countries published a total of 13 articles concerning amyloidosis which makes 4.7% of the total Arabic FMF published articles. This study reflects an undoubtable need for more research to be conducted on FMF by the Arab countries, which suffer greatly from immense shortage in research productivity, due to the many obstacles and limitations these countries face every day.

Differential mutational profiles of familial Mediterranean fever in North Africa

Familial Mediterranean fever (FMF) is a recessive autoinflammatory disease, mainly occurring in the eastern Mediterranean. In these populations, the five FMF founder mutations are differently distributed. In Algeria, the FMF-causing variants remain poorly explored. This retrospective study aims to report the mutational profile of Algerian FMF patients and to compare it with North African FMF patients. One hundred eighty-three unrelated patients clinically suspected of FMF were recruited from various Algerian hospitals (2007-2015) and tested for mutations in exon 10 of MEFV gene. Molecular analysis identified 144 mutant alleles among 87 of 183 patients (47.5%). p.M694I was the most prevalent pathogenic allele, accounting for 63.2% of mutant alleles, followed by p.M694V and p.M680I occurring with a same frequency (14.5%). Others, p.A744S (6.2%) and p.I692del (1.3%), are less frequent. Interestingly, p.M694I was the most recurrent in patients with renal AA-amyloidosis. Our results provide the first genetic data on FMF in Algeria, demonstrating the predominance of p.M694I and the absence of p.V726A, compared to other North African countries (Morocco, Tunisia, and Egypt). In conclusion, North African FMF patients display differential mutational profiles that may result from the difference in ethnic origin and the genetic heterogeneity among these populations.

Spectrum of MEFV Variants and Genotypes among Clinically Diagnosed FMF Patients from Southern Lebanon

Background: Familial Mediterranean Fever (FMF) is an autosomal recessive auto-inflammatory disease characterized by pathogenic variants in the MEFV gene, with allele frequencies greatly varying between countries, populations and ethnic groups. Materials and methods: In order to analyze the spectrum of MEFV variants and genotypes among clinically diagnosed FMF patients from South Lebanon, data were collected from 332 participants and 23 MEFV variants were screened using a Real-Time PCR Kit. Results: The mean age at symptom onset was 17.31 ± 13.82 years. The most prevalent symptoms were abdominal pain, fever and myalgia. MEFV molecular analysis showed that 111 patients (63.79%) were heterozygous, 16 (9.20%) were homozygous, and 47 (27.01%) carried two variants or more. E148Q was the most encountered variant among heterozygous subjects. E148Q/M694V was the most frequent in the compound heterozygous/complex genotype group, while M694I was the most common among homozygous patients. Regarding allele frequencies, M694V was the most common variant (20.7%), followed by E148Q (17.1%), V726A (15.7%) and M694I (13.2%). Conclusion: The high percentage of heterozygous patients clinically diagnosed as FMF highlights the pseudo-dominant transmission of the disease in Lebanon and emphasizes the importance of molecular testing for a more accurate diagnosis and better management and treatment of FMF.

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.

Effects of mating patterns on genealogical trees: Assessment of the high carrier rate of Familial Mediterranean Fever in rural Israeli districts

We investigate the spread from ancestors to descendants, under a model of sexual reproduction, of hereditary elements distinguishing individuals from their fellow human beings. These hereditary elements, termed labels, are either symbolic, implying a socio-cultural or ethnic self-determined category, or biological, i.e. a DNA sequence (for example founder mutations). The impact of various modes of preferential (assortative) mating on the dissemination of a known ancestral label was studied for both kinds of labels, the symbolic and the biological. For the socio-cultural based labeling, both mathematical modeling and simulation studies were carried out, and disclosed a marked delay in the spread of the labels in future generations, compared to the case where mating was random. The transmission of biological labels (founder mutations) from an ancestor to descendants under various modes and degrees of assortative mating was investigated by simulations and supplemented by an in-depth analysis of allele frequencies of Familial Mediterranean Fever (FMF) in an Israeli Muslim Arab village. The high carrier frequency of FMF in this village was satisfactorily explained solely by the presence of a founder effect and a pronounced high factor of selective mating, causing segregation and consanguinity among its inhabitants. Contribution of further evolutionary mechanisms such as heterozygote advantage, drift, differential reproductive success or selection pressure was not essential to explain these results.

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

The aim of the current study was to determine the frequency of the Mediterranean fever (MEFV) gene pathogenic variants in 60 children diagnosed with familial Mediterranean fever (FMF) and to compare the phenotype-genotype correlation. Genomic DNA was isolated by the spin-column method from peripheral blood samples (collected in vacutainers containing EDTA) and buccal smears. The MEFV gene profiles for the current FMF cohort were genotyped by pyrosequencing and direct Sanger sequencing techniques for the target pathogenic variants. The most prominent clinical symptoms were abdominal pain (53.4%), fever (23.4%) and arthritis (23.3%). Eighteen different pathogenic variants were identified and the most frequent were p.Met694Val (20.0%), p.Glu148Gln (13.3%), p.Met680 Ile (11.7%) and p.Arg202Gln (11.7%). Abdominal pain, fever and arthritis were the most common presenting clinical characteristics. Results showed that not only clinical characteristics, but also genotyping of the MEFV gene is needed to establish the correct diagnosis of FMF in children and other family members.

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.

MEFV mutations in Egyptian children with systemic-onset juvenile idiopathic arthritis

BACKGROUND AND OBJECTIVES

Systemic-onset juvenile idiopathic arthritis (SoJIA) is a chronic auto-inflammatory disease of childhood, with a complex genetic trait, which is characterized by arthritis associated with systemic manifestations. Familial Mediterranean fever (FMF) is another auto-inflammatory disorder that is monogenic. There are speculations as to whether Mediterranean fever (MEFV) mutations are among the genetic determinants of SoJIA. Our aim was to explore the frequency and clinical significance of MEFV mutations in Egyptian SoJIA patients. A group of healthy children were assigned to the control group in an attempt to estimate the carrier rate of MEFV mutations in Egypt.

METHODS

Eighty-four children were recruited in this study; 54 children, age (mean ± standard deviation; 8.31 ± 2.85 years), diagnosed as having SoJIA with no typical symptoms of FMF; 30 healthy age- and gender-matched children served as the control group. All recruited children were screened for 12 common MEFV mutations using a reverse hybridization assay of biotinylated PCR products.

RESULTS

SoJIA patients had a significantly higher frequency of MEFV mutations (66.7 %) than in the healthy control population (16.7 %). V726A was the leading mutation in SoJIA patients, with an allelic frequency of 15.74 %, followed by E148Q, with an allelic frequency of 7.4 %. Children who were carriers of MEFV mutations had an 18 times higher risk of developing SoJIA than wild-type carriers [odds ratio 18.0 (95 % CI 5-69), P < 0.01]. E148Q was the leading mutation, present in 13.3 % of healthy controls.

CONCLUSION

These findings suggest that MEFV mutations may be responsible for auto-inflammatory diseases other than FMF, and patients with SoJIA, especially those with a positive family history of FMF or SoJIA, should be screened for MEFV mutations in countries where FMF is frequent.

Frequency of MEFV gene mutations in Hatay province, Mediterranean region of Turkey and report of a novel missense mutation (I247V)

In the present study, 1000 patients with clinical suspicion of FMF were retrospectively reviewed to determine the spectrum of MEFV gene mutations by using DNA sequence analysis between September, 2008 and April, 2012. Sixteen different mutations and 55 different genotypes were detected in 618 of 1000 patients. Among 16 different mutations, R202Q (21.35%) was the most frequently observed mutation; followed by E148Q (8.85%), M694V (7.95%), M680I (2.40%), V726A (1.85%), M694I (0.95%), A744S (0.80%), R761H (0.55%), P283L (0.35%), K695R (0.20%), E230K (0.15%), L110P (0.10%), I247V (0.05%), G196W (0.05%) and G304R (0.05%). In the present study, a novel missense mutation (I247V) and a silent variant (G150G) were identified in the MEFV gene. On the other hand, P238L, G632A and G304R mutations are the first cases reported from Turkey. Our results indicated that MEFV mutations are highly heterogeneous in our study population as in other regions of Turkey and mutation screening techniques such as PCR-RFLP, amplification refractory mutation system or reverse hybridization do not adequately detect uncommon or novel mutations. Therefore, it was proven that sequence analysis of the MEFV gene could be useful for detection of rare or unknown mutations.

High frequency of inherited variants in the MEFV gene in patients with hematologic neoplasms: a genetic susceptibility?

Familial Mediterranean fever is an autosomal recessive disease occurring in populations originating from the Mediterranean basin. This autoinflammatory syndrome is caused by mutations in the Mediterranean FeVer (MEFV) gene. MEFV encodes a 781 amino acid protein known as pyrin. Pyrin is an important modulator of apoptosis, inflammation, and cytokine processing. In more recent pilot studies, inherited variant analysis of the MEFV gene in patients with hematologic neoplasm showed an unexpectedly high frequency of these variants in the gene. Here, we summarize the current state of knowledge of the relationship between inherited variants in the MEFV gene and hematologic neoplasms. Although no single underlying defect could be targeted in all hematologic neoplasms, it will be important to fully exploit the mechanisms underlying the neoplasm promoting role of inherited variants in MEFV. However, it is unclear how inherited variants in the MEFV gene are associated with tumor susceptibility or promotion in hematologic neoplasms. Further investigations are needed to determine the actual role of the MEFV gene in pathogenesis of these neoplasms.

Estimating the allele frequency of autosomal recessive disorders through mutational records and consanguinity: the Homozygosity Index (HI)

In principle mutational records make it possible to estimate frequencies of disease alleles (q) for autosomal recessive disorders using a novel approach based on the calculation of the Homozygosity Index (HI), i.e., the proportion of homozygous patients, which is complementary to the proportion of compound heterozygous patients P(CH). In other words, the rarer the disorder, the higher will be the HI and the lower will be the P(CH). To test this hypothesis we used mutational records of individuals affected with Familial Mediterranean Fever (FMF) and Phenylketonuria (PKU), born to either consanguineous or apparently unrelated parents from six population samples of the Mediterranean region. Despite the unavailability of precise values of the inbreeding coefficient for the general population, which are needed in the case of apparently unrelated parents, our estimates of q are very similar to those of previous descriptive epidemiological studies. Finally, we inferred from simulation studies that the minimum sample size needed to use this approach is 25 patients either with unrelated or first cousin parents. These results show that the HI can be used to produce a ranking order of allele frequencies of autosomal recessive disorders, especially in populations with high rates of consanguineous marriages.

Familial Mediterranean fever in a large Lebanese family: multiple MEFV mutations and evidence for a Founder effect of the p.[M694I] mutation

Familial Mediterranean fever (FMF) is an autoinflammatory autosomal recessive disease characterized by recurrent fever crises and serous inflammation. The MEFV gene responsible for the disease was identified on chromosome 16, and 5 of the mutations discovered so far in the gene are most frequently encountered in FMF patients: p.[M694V], p.[V726A], p.[M680I] and p.[M694I] in exon 10, and p.[E148Q] in exon 2. The present work describes multiple MEFV mutations and the corresponding haplotypes for 31 FMF patients as well as 32 "healthy" individuals of a large consanguineous Lebanese family. The DNAs were screened for MEFV mutations, and determination of the corresponding haplotypes was performed for all individuals by genotyping 4 microsatellites surrounding the gene. Five different mutations were detected in this one family, which is unexpected in such a genetic isolate. A phenotypic variability was also observed. The haplotype carrying the p.[M694I] allele, detected in all the family branches, was well conserved and therefore seems to be the ancestral one.

1Novel MEFV transcripts in Familial Mediterranean fever patients and controls

Background

Familial Mediterranean fever is a recessive autoinflammatory disease frequently encountered in Armenians, Jews, Arabs and Turks. The MEFV gene is responsible for the disease. It encodes a protein called pyrin/marenostrin involved in the innate immune system. A large number of clinically diagnosed FMF patients carry only one MEFV mutation. This study aims at studying the MEFV gene splicing pattern in heterozygous FMF patients and healthy individuals, in an attempt to understand the mechanism underlying the disease in these patients.

Methods

RNA was extracted from peripheral blood leucocytes of 41 FMF patients and 34 healthy individuals. RT-PCR was then performed, and the amplified products were migrated on a polyacrylamide electrophoresis gel, characterized by gel extraction of the corresponding bands followed by sequencing.

Results

Five novel splicing events were observed in both patients and controls deleting either exons 3, 4 (del34), or exons 2, 3, 4 (del234), or exons 2, 3, 4, 5 (del2345) or exon7 (del7) or exons 7 and 8 (del78).

Conclusions

The observation of such qualitative variability in the expression of the MEFV gene suggests a complex transcriptional regulation. However, the expression of these novel transcripts in both patients and controls is not in favour of a severe pathogenic effect.

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.

Familial Mediterranean fever in Syrian patients: MEFV gene mutations and genotype-phenotype correlation

Familial Mediterranean fever is an autosomal recessive disorder characterized by recurrent attacks of abdominal pain, synovitis and pleuritis. MEFV gene mutations are responsible for the disease. The objective of this study was to identify the frequency and distribution of 12 MEFV mutations in 153 Syrian patients and perform a genotype-phenotype correlation in the patients' cohort. Of the 153 unrelated patients investigated, 97 (63.4%) had at least one mutation. The most frequent mutation was M694V (36.5%), followed by V726A (15.2%), E148Q (14.5%), M680I (G/C) (13.2%), and M694I (10.2%) mutations. Rare mutations (R761H, A744S, M680I (G/A), K695R, P369S, F479L and I692del) were also detected in the patients. M694V was associated with the severe form of the disease. The identification of a significant number of FMF patients with no mutations or only one known mutation identified indicates the presence of new mutations in the MEFV gene which will be investigated in the future.

Comparison of the results of PCR-RFLP and reverse hybridization methods used in molecular diagnosis of FMF

Familial Mediterranean fever (FMF) is characterized by recurrent fever, serositis, and arthritis. Due to the abundance of mutations and clinical heterogeneity of the disease, different screening methods have been developed. In this study, we aimed to compare our findings of mutations determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with reverse hybridization (RH) methods. In 152 of 263 patients (57.79%) different mutations were determined with RH. Allelic frequencies were E148Q 6.84%, M680I(G/C) 3.61%, M694V 20.91%, V726A 7.03%, P369S 1.33%, F479L 0.19%, M680I(G/A) 0.76%, M694I 0.57%, K695R 0.57%, A744S 0.38%, R731H 0.38%, and del1692 0%. Frequent mutations were also confirmed by PCR-RFLP. There were no conflicting results between the two methods. Four of these genotypes were homozygous for a single mutation, 15 were heterozygous for two mutations, 8 were heterozygous for a single mutation, 1 was heterozygous for three mutations, and 1 was homozygous for one mutation and heterozygous for another mutation. It has been reported that analytical sensitivity of RH is 97%. We did not find a discrepancy between the two methods. In 21 patients, we detected additional mutations with RH. This finding was regarded as an advantage of RH, and we concluded that this assay is a useful method for detection of first stage FMF mutation screening.

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.

Familial Mediterranean Fever in Lebanon: founder effects for different MEFV mutations

Haplotype analysis of 376 Familial Mediterranean Fever (FMF) patients and 100 controls from Lebanon was performed using 4 microsatellite loci to study founder effects for the five most frequent mutations within the MEFV gene (M694V, M694I, V726A, M680I and E148Q). Each of these mutations was associated with a particular haplotype that was less frequent among controls, confirming that they have probably arisen from unique mutation events and that the carrier chromosomes derived from a common ancestor. The estimated ages of the most recent common ancestor for each of the 5 mutations, using the ESTIAGE program, were 7000, 8500, 15000, 23000 and 30000 years for M694V, M694I, V726A, M680I and E148Q, respectively. Varying the mutation rate at one of the markers led to younger age estimates, but the mutation E148Q remained the oldest one. Comparison of haplotype distributions among the different Lebanese religious groups confirmed that Muslim sub-populations (Shiites and Sunnites) as well as Christian ones, including Armenians who were formerly settled in the South-Eastern part of Asia Minor (Cilicia), are all derived from an ancient common ancestral population in which most of the MEFV mutations were already present with their respective associated haplotypes.

MEFV gene mutations spectrum among Lebanese patients referred for Familial Mediterranean Fever work-up: Experience of a major tertiary care center

Familial Mediterranean Fever (FMF) is an autosomal recessive inflammatory disorder predominantly affecting people living in or originating from areas around the Mediterranean Sea, mainly Jews, Armenians, Turks, and Arabs. It is characterized by recurrent attacks of inflammation of serosal membranes and fever resulting in acute abdominal, chest, or joint pain. Over 50 MEditerranean FeVer (MEFV) mutations and polymorphisms have been identified in FMF patients. The objective of this study was to analyze the distribution and frequencies of 12 MEFV mutations in 266 referred Lebanese patients using a reverse-hybridization assay. Of the 266 patients, 129 (48.5%) were positive for at least one mutation and 137 (51.5%) had no mutations detected. Of the 129 patients with mutations, 35 were homozygous, 41 were compound heterozygous and 53 were heterozygous. The five most common mutations M694V, E148Q, V726A, M694I and M680I (G/C) accounted for 26.1, 22.2, 21.3, 9.6 and 7.7%, respectively. The A744S, F479L, R761H and I692del were encountered in 2.9% of patients; P369S and M680I (G/A) were found in 1.2% of patients while K695R was absent. The spectrum of the MEFV mutations among our sampled Lebanese FMF patients shows the high heterogeneity at the allelic level when compared to Arab and non-Arab populations. The most important feature was the relatively high frequency of the E148Q in our study group that allows us to question it as a mutation rather than a polymorphism. Further studies should be conducted to evaluate the role of the E148Q allele.

MEFV alterations and population genetics analysis in a large cohort of Greek patients with familial Mediterranean fever

Familial Mediterranean fever (FMF) is a disease characterized by recurrent, self-limiting bouts of fever and serositis and caused by altered pyrin due to mutated MEFV gene. FMF is common in the Mediterranean Basin populations, although with varying genetic patterns. The spectrum and clinical significance of MEFV alterations in Greece has yet not been elucidated. The aim of this study was to analyze the spectrum of MEFV alterations in FMF patients and healthy individuals in Greece. A cohort of 152 Greek FMF patients along with 140 Greek healthy controls was enrolled. Non-isotopic RNase cleavage assay (NIRCA) and sequencing allowed mutational and haplotypic analysis of the entire coding sequence of MEFV. The ARLEQUIN 2.0, DNASP 4.0 and PHYLIP software were used for population genetics analysis. Among patients, 127 (83.6%) carried at least one known mutation. The most common mutations identified were M694V (38.1%), M680I (19.7%), V726A (12.2%), E148Q (10.9%) and E230K (6.1%). The total carrier rate among healthy individuals was 0.7%. The presence of R202Q homozygosity in 12 of the remaining 25 MEFV negative FMF patients might be considered as disease related in Greeks. Population genetics analysis revealed that Greeks rely closer to the eastern rather than western populations of the Mediterranean Basin.

Mutational analysis of the PRYSPRY domain of pyrin and implications for familial mediterranean fever (FMF)

Familial Mediterranean fever (FMF) is an autosomal, recessively inherited disease, characterized by recurrent fever and serositis that affects mainly patients of the Mediterranean basin. The gene responsible for FMF, named MEFV, was cloned and several missense mutations were found to be responsible for the disease. Based on a recent molecular analysis of MEFV gene mutations in 43 patients from Crete aiming to correlate specific genotypes and clinical manifestations of FMF, we were prompted to construct a three-dimensional model (3-D model) of the PRYSPRY domain of pyrin. The majority of the known MEFV mutations located on this domain have been classified, according to disease severity, and localized on this 3-D model. The functional consequences of these mutations and their implications on disease severity are discussed. Moreover, we report a putative novel missense mutation, S702C, which we identified in exon 10 of the MEFV gene and localized on the constructed 3-D model.