Genetic screening of fourteen mutations in Jordanian familial Mediterranean fever patients

Old paradigms and new concepts in familial Mediterranean fever (FMF): an update 2023

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized by recurrent attacks of fever and polyserositis. Its first description as a new entity was published by Siegal in 1945. Colchicine has been the treatment of choice for this disease since 1972. Significant progress has been made over the years in understanding FMF's clinical features, diagnosis, mode of inheritance, pathogenesis and therapeutic approach. However, many old paradigms related to FMF have proven inaccurate, leading to the emergence of new concepts that provide more precise insights. The term 'FMF' is no longer appropriate as the disease is found beyond the Mediterranean basin. The concept of diagnosis based only upon clinical ground proved to be wrong. The paradigm that MEFV mutations in FMF lead to loss of function of the encoded peptide pyrin turned out to be a gain of function mutation. Finally, the concept that as a genetic disease FMF should be treated for life was found to be inaccurate for the subpopulation of the heterozygote patients. Thus, the breakthroughs of identifying the gene associated with the disease (MEFV) and the deciphering of its pathogenesis revolutionized our old paradigms and replaced them with new and more precise insights.

Atypical Autosomal-Dominant Inheritance of Familial Mediterranean Fever

Familial Mediterranean fever (FMF) was previously believed to be an autosomal recessive disease. We present a patient with only one pathogenic variation of the MEFV gene due to the c.2177T>C mutation. The patient had clinical features of recurrent fevers and abdominal pain, serositis, and a history of multiple abdominal surgeries for pain. He was eventually diagnosed with FMF. This case report demonstrates an example of the rare autosomal-dominant phenotype of FMF.

Genetic Profile of Patients with Familial Mediterranean Fever (FMF): Single Center Experience at King Hussein Medical Center (KHMC)

Objective:

To describe the spectrum of genetic mutations in patients with clinical diagnosis of Familial Mediterranean Fever.

Method:

This is a retrospective study of 3359 sera samples for patient with clinical diagnosis of FMF, over a period of 6 years. The samples were tested for 12 mutations of the MEFV gene by PCR& hybridization of the PCR product with Probes immobilized as an array of panel lines.

Results:

A total of 1868 (55.6%) samples were found negative, and one or more mutations were detected in 1491 (44.4%) distributed along the mutations. Of the positive results, the Frequency of the mutations was as follows, the M694V was the most common mutation 30%, followed by E 148Q 21.5%, V 726 A 20%, M6801 G/C 9%, M6941 8.3%, P369s 3.7%, A744S 3.1% and 4.2% among the 4 remaining mutations.

Conclusion:

Frequency of common mutations in our study show similar results in comparisons with Mediterranean countries like Egypt, Turkey, and Syria with the most common mutation in our study being M694V followed by E148 Q.

Prevalence of common MEFV mutations and carrier frequencies in a large cohort of Iranian populations

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disorder caused by mutations in the MEFV gene. The disease is especially common among Armenian, Turkish, Jewish and Middle East Arab populations. To identify the frequency and the spectrum of common MEFV mutations in different Iranian populations, we investigated a cohort of 208 unselected asymptomatic individuals and 743 FMF patients. Nine hundred and fifty-one samples were analysed for the presence of 12 MEFV mutations by PCR and reverse-hybridization (FMF StripAssay, ViennaLab, Vienna, Austria). Confirmatory dideoxy sequencing of all MEFV gene exons was performed for 39 patients. Fifty-seven (27.4%) healthy individual carried mutant MEFV alleles. Three hundred and ninety-one (52.6%) FMF patients were found positive for either one (172/743; 23.1%), two or three MEFV mutations. Using dideoxy sequencing, three novel variants, A66P, R202W and H300Q, could be identified. Our analysis revealed an allele frequency and carrier rate of 15.6 and 27.4%, respectively, among healthy Iranians. Still moderate compared to neighbouring Armenia, but higher than in Turkey or Iraq, these data suggest that FMF is remarkably common among Iranian populations. E148Q was most frequent in the group of healthy individuals, whereas M694V was the most common mutation among FMF patients, thereby corroborating previous studies on MEFV mutational spectra in the Middle East. Accordingly, MEFV mutations are frequent in healthy Iranian individuals across different ethnic groups. Based on this finding, the awareness for FMF and the implementation of augmented carrier screening programmes considering the multiethnic nature of the Iranian population should be promoted.

MEFV mutations in Iranian Azari Turkish patients with Henoch-Schönlein purpura

BACKGROUND/AIM

The aim of the current study was to screen the rate of MEFV mutations in Henoch-Schönlein purpura (HSP) and to investigate the association of these mutations plus clinical symptoms with HSP disease in the Iranian Azari Turkish ethnic group.

MATERIALS AND METHODS

The study groups included 40 unrelated HSP patients and 200 apparently healthy people without any kind of inflammatory diseases as a control group. Molecular screening was performed for eight main mutations, namely M694V, M694I, M680I, V726A, E148Q, R761H, P396S, and R408Q, using polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and sequencing.

RESULTS

Out of the 40 studied patients, 27 subjects (67.5%) did not show any mutation, whereas 10 patients (25%) were heterozygotes for one of the following mutations: M694V, M680I, V726A, E148Q. Moreover, three patients (7.5%) were compound heterozygotes for P369S and R408Q. The significant differences between the patient and control groups for M680I, V726A, E148Q, P396S, and R408Q were P = 0.0043, P = 0.0324, P = 0.0145, P = 0.0043, and P = 0.0043, respectively. Furthermore, no significant difference in clinical manifestations was observed between the two groups of patients with and without mutations.

CONCLUSION

Based on the results, MEFV mutations could be considered effective genetic factors for development of HSP in the Iranian Azari Turkish ethnic group.

The association of endoplasmic reticulum aminopeptidase-1 (ERAP-1) with Familial Mediterranean Fever (FMF)

BACKGROUND

The ERAP1 gene cleaves the receptors and reduces their ability to transmit chemical signals to the cell that affect the process of inflammation and, secondly, it cleaves many types of proteins into small peptides that are recognized by the immune system.

OBJECTIVE

ERAP-1 gene mutations may create a sensitivity for Familial Mediterranean Fever (FMF).

METHOD

We included 15 FMF patients with the M694 (+) mutation in the study in order to exclude patients without pyrin gene mutations and create a homogeneous study group. Fifteen patients with ulcerative colitis formed the control group.

RESULTS

There wasn't any case without ERAP-1 gene mutations. At least one mutation at exon 3 or exon 10 was found in all cases in both groups. There were 14 ERAP-1 gene mutations at exon 10 and 11 at exon 3 in patients with FMF. Interestingly, if there were ERAP-1 gene mutations at exon 3, a p.Arg127 Pro (c.380 G>C) mutation always existed for three FMF patients with polymorphic mutations at this exon. There were 11 ERAP-1 gene mutations at exon 10 and 12 gene mutations at exon 3 in patients with ulcerative colitis. Exon 3 mutations were usually single p.Arg127 Pro (c.380 G>C) mutations for 12 patients with ulcerative colitis as seen in the patients with FMF. The single mutation was always p.Ser453 Ser (c.1359T>C) for patients with ulcerative colitis at exon 10.

CONCLUSION

There are more ERAP-1 mutations in the FMF group in comparison to the ulcerative colitis group. So, there may be a strong susceptibility to ERAP-1 gene mutations in FMF patients according to our results. However, further studies with larger study and control groups are needed.

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.

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.

Frequency of MEFV mutation and genotype-phenotype correlation in cases with dysmenorrhea

AIM

We aimed to investigate the relation between mutations and polymorphisms playing roles in the onset of clinical findings of Familial Mediterranean Fever (FMF) and clinical phenotypic reflections manifesting with painful episodes, such as dysmenorrhea.

MATERIAL AND METHODS

A total of 1000 female patients who had not responded well to non-steroidal anti-inflammatory drugs in the menstrual period, and who had presented to the emergency room with the complaint of recurrent pain episodes were included in the study. All the patients were Turkish women living in Istanbul. In this study, the mutations most frequently seen in the Mediterranean Fever Gene (MEFV), namely M694V, E148Q, M680I(G/C), V726A, P369S, R761H, A744S, M694I, K695R, F479L, M680I(G/A), and I692del were examined using the DNA sequence analysis following DNA isolation.

RESULTS

The number of individuals who had a mutation in at least one allele for FMF was 511 out of 1000 patients. Of these 511 patients, homozygous mutations were found in 21% (n = 109), compound heterozygous mutations were found in 27% (n = 136), and heterozygous mutations were found in 52% (n = 266). The most frequent homozygous genotype seen in our study population was M694V/M694V. The most common compound heterozygote genotypes were M694V/M680I, M694V/V726A, M694V/E148Q, and M680I/V726A; and 11.7% (n = 60) of the families in whom mutations were found had consanguinity.

CONCLUSION

Women who present to the emergency room with the complaint of dysmenorrhea that is irresponsive to non-steroidal anti-inflammatory drugs may have several types of MEFV mutations that are responsible for FMF.

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.

Familial Mediterranean fever with a single MEFV mutation: where is the second hit?

OBJECTIVE

Familial Mediterranean fever (FMF) has traditionally been considered an autosomal-recessive disease; however, it has been observed that a substantial number of patients with clinical FMF possess only 1 demonstrable MEFV mutation. The purpose of this study was to perform an extensive search for a second MEFV mutation in 46 patients diagnosed clinically as having FMF and carrying only 1 high-penetrance FMF mutation.

METHODS

MEFV and other candidate genes were sequenced by standard capillary electrophoresis. In 10 patients, the entire 15-kb MEFV genomic region was resequenced using hybridization-based chip technology. MEFV gene expression levels were determined by quantitative reverse transcription-polymerase chain reaction. Pyrin protein levels were examined by Western blotting.

RESULTS

A second MEFV mutation was not identified in any of the patients who were screened. Haplotype analysis did not identify a common haplotype that might be associated with the transmission of a second FMF allele. Western blots did not demonstrate a significant difference in pyrin levels between patients with a single mutation and those with a double mutation; however, FMF patients of both types showed higher protein expression as compared with controls and with non-FMF patients with active inflammation. Screening of genes encoding pyrin-interacting proteins identified rare mutations in a small number of patients, suggesting the possibility of digenic inheritance.

CONCLUSION

Our data underscore the existence of a significant subset of FMF patients who are carriers of only 1 MEFV mutation and demonstrate that complete MEFV sequencing is not likely to yield a second mutation. Screening for the set of the most common mutations and detection of a single mutation appears to be sufficient in the presence of clinical symptoms for the diagnosis of FMF and the initiation of a trial of colchicine.

Clinical and Genetic Features of Familial Mediterranean Fever in Japan

Objective.

Familial Mediterranean fever (FMF) is thought to be a rare disorder in Japan, and the clinical features of Japanese patients with FMF remain unclear. Our aim was to elucidate the clinical characteristics of FMF in Japanese patients.

Methods.

We analyzed clinical and genetic data of 80 patients based on the results of a nationwide questionnaire survey and review of the literature.

Results.

From clinical findings of 80 Japanese patients, high-grade fever was observed in 98.8%, chest attacks (pleuritis symptoms) in 61.2%, abdominal attacks (peritonitis symptoms) in 55.0%, and arthritis in 27.5%. Twenty-four percent of patients experienced their first attacks before 10 years of age, 40% in their teens, and 36% after age 20 years. Colchicine was effective in many patients at a relatively low dose (< 1.0 mg/day). AA amyloidosis was seen in only 1 patient. Common MEFV mutation patterns were E148Q/M694I (25.0%), M694I alone (17.5%), and L110P/E148Q/M694I (17.5%), and no patient carried the M694V mutation, the most common mutation in Mediterranean patients with FMF.

Conclusion.

A larger than expected number of patients with FMF exist in Japan, and the clinical presentation of Japanese FMF patients seems to be relatively milder than those of Mediterranean FMF patients. AA amyloidosis rarely occurs in Japanese patients, probably due to difference in patterns of the MEFV genotype between Japanese and Mediterranean patients.

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.

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.

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.

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.

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.

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.

Jordan: communities and community genetics

The population in Jordan mounted from half a million in 1952 to 5.3 millions in 2004 and is composed of a variety of ethnic groups, the majority being Arabs. Couples nowadays tend to have fewer children, with the total fertility rate falling from 7.4 in 1976 to 3.7 in 2004. Consanguineous marriages are traditionally favored, with the preferred marriage partner being the offspring of the father's brother. First-cousin marriages declined from 28.5% for marriages contracted between 1950 and 1979 to 19.5% for marriages contracted after 1980. In the overall population, carrier rates for beta-thalassemia, alpha-thalassemia and sickle cell anemia are in the range of 2-4%, 3.2-12% of males have glucose-6-phosphate dehydrogenase deficiency, and the prevalences for familial Mediterranean fever and cystic fibrosis were estimated at around 0.04% each. A mandatory premarital screening program for beta-thalassemia carriers commenced in June 2004. The high consanguinity rate and the large family size in Jordan have contributed to the description of a number of rare and new autosomal recessive conditions. Genetic services in Jordan are still scarce and do not cover all the country due to the major impediments of a paucity of resources and trained health professionals in the area of medical genetics. The demographic data suggest that the health system in Jordan is capable of introducing some basic community genetic services into the primary health care program through comprehensive and cost-effective programs.

Familial Mediterranean fever in the Syrian population: gene mutation frequencies, carrier rates and phenotype–genotype correlation

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive disease mainly affecting particularly Arabs, Non-Ashkenazi Jews, Armenians, and Turks. It is an autoinflammatory periodic disorder characterized by febrile and painful attacks due to inflammation involving the serosal membranes in the abdomen, chest or joints. Over 50 mutations have been identified in the MEFV gene responsible for FMF.

OBJECTIVE

To identify the distribution and the frequency of the MEFV gene mutations in Syrian FMF patients and population and perform a genotype/phenotype correlation in the patients' cohort.

PATIENTS AND METHODS

The study was carried out on 83 clinically diagnosed Syrian FMF patients and 242 healthy subjects. The tested individuals were screened for the most common five MEFV mutations (M694V, M694I, M680I, V726A and E148Q) by restriction fragment length polymorphism. Sequencing of exon 10 was performed only for the patients' DNA where just one or no mutation was detected.

RESULTS AND DISCUSSION

Of the 83 patients studied, 74 (89%) were positive either for one, two or three mutations and nine (11%) had no mutations detected. Of those positive for mutations, 25 were homozygous, 30 were compound heterozygotes, three had complex alleles, and 16 patients had only one mutation. The M694V, V726A, M694I, M680I and E148Q mutations accounted for 45.8%, 26%, 13.9%, 4.8% and 6% of the alleles, respectively. The carrier rate in the Syrian population for the tested mutations was 17.5%, E148Q being the most common mutation, followed by V726A and M694V. The severity of the disease and development of amyloidosis seem to have an association with M694V, the most common mutation in Syrian FMF patients.

Familial mediterranean fever in Arabs

Autoinflammatory diseases are a group of disorders characterised by seemingly unprovoked inflammation in the absence of high-titre autoantibodies or antigen-specific T cells, and include the hereditary periodic fever syndromes. Familial Mediterranean fever (FMF) is an archetypal autoinflammatory disorder, which is autosomal recessive and has a high prevalence in non-Ashkenazi Jews, Armenians, Turks, and Arabs. The classic clinical picture is recurrent acute short-lived febrile and painful attacks with variable periods of remission. In a subset of patients, the disorder is complicated by amyloidosis that leads to renal failure. The gene responsible for FMF--MEFV--has been identified and its role in inflammation is being assessed. There seems to be a distinctive clinical picture in Arab patients with FMF, and the range and distribution of MEFV mutations is different from that noted in other affected ethnic groups. Here, we discuss the clinical and molecular aspects of FMF in Arabs.

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

Familial Mediterranean fever (FMF) is an autosomal recessive disease mostly frequent in Mediterranean populations. Over 50 mutations have been identified in the gene responsible for the disease, MEFV. The present study reports the frequencies of MEFV mutations in 558 Lebanese and 55 Jordanian FMF patients and points out the severity of the M694V frequently observed mutation among these patients. Three novel mutations, T177I, S108R and E474K were also identified in the Lebanese group. An excess of homozygotes and a deficit of heterozygotes were observed in both samples when compared to the expected number of observed genotypes under the Hardy-Weinberg hypothesis. Homozygotes for M694V and M694I were still in excess in the Lebanese group of patients, even after consanguinous homozygotes were removed, or population structure was considered. This excess is therefore neither due to consanguinity nor to subgroups in the Lebanese population, but rather to more remote consanguinity or to a selection bias favoring the census of these genotypes. The fact that FMF female patients were less censed than male patients may be due to the greater resistance of females to pain and to the possibility of confusing abdominal and gynecological pain. The phenotypic heterogeneity of the FMF could then originate both from genetic causes like allelic heterogeneity or modulating genes, and cultural background facing the physiological consequences of genotypes at risk.

Comparison of Amplification Refractory Mutation System and Polymerase Chain Reaction-Restriction Fragment Length Polymorphism Techniques Used for the Investigation of MEFV Gene Exon 10 Point Mutations in Familial Mediterranean Fever Patients Living in Çukurova Region (Turkey)

Familial Mediterranean fever (FMF) is an autosomal recessive inherited disease characterized by recurrent fever, serositis and arthritis. The disease is highly prevalent in Mediterranean basin populations. Recently, the gene responsible for FMF (MEFV) was cloned and at least 40 MEFV gene mutations have been identified. The most frequently observed mutations in the MEFV gene are M694V, M694I, M680I, and V726A. These occur within exon 10 of the gene, and account for 85% of the known MEFV alleles. In this study, the reliability and economical aspects of amplification refractory mutation system (ARMS) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques were compared for analyzing the frequencies of the major point mutations of 90 unrelated patients with FMF from the Cukurova region in Turkey. Both techniques yielded similar results: The ratio of independent alleles of 90 patients carrying one of the tested mutations was 81.1%; patients consisted of 12 different genotypes. In 64 of 90 patients (71.1%) mutations were observed in both alleles. Thirty-six patients (40%) were homozygous for the same mutation, 28 (31.1%) were heterozygous for different mutations. Eighteen patients (20%) were heterozygous for one allele with one of the four mutations but the other allele was unknown. In 8 patients (8.8%) no mutation could be detected. The most frequently observed mutation was M694V (51.66%), followed by M680I (17.22%), V726A (10.55%), and M694I (1.66%). In conclusion ARMS and PCR-RFLP techniques were equally reliable to detect the mutations in Turkish FMF patients. However, the ARMS technique was found to be more rapid and economical than the PCR-RFLP techniques.

The Spectrum of Familial Mediterranean Fever Gene Mutations in Arabs: Report of a Large Series

OBJECTIVES

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

PATIENTS AND METHODS

The study was performed in the pediatric FMF clinic of Jordan University Hospital over a period of 4 years. Patients were referred by their physicians for diagnosis, management, genetic study, and counseling. A diagnosis of FMF was made according to published criteria. Screening for 5 mutations, namely M694V, V726A, M694I, M680I, and E148Q, was performed by amplification refractory mutation system (ARMS) for the first 4 and by restriction endonuclease testing for E148Q.

RESULTS

Of the 407 unrelated patients investigated, 239 (59%) had 1 or 2 mutations and 168 (41%) had none of the studied mutations detected. Of those with mutations, 92 were homozygous, 53 were compound heterozygotes, 3 had complex alleles, and 91 patients had only 1 identifiable mutation. Of the mutations, M694V, V726A, M694I, M680I, and E148Q accounted for 38, 26, 14, 10 and 13%, respectively. Twelve of our patients developed the protracted febrile myalgia syndrome (PFMS) of whom 5 (42%) were homozygous for M694V. Only 2 developed chronic renal failure, both of whom were homozygous for M694V and were not on colchicine prophylaxis. However, 43 patients had a family history of chronic renal failure, and 15 (35%) were homozygous for M694V.

CONCLUSIONS

Our data indicate that the 5 MEFV mutations are well distributed in Arabs. They also show that M694V is the most common mutation in Arab patients with FMF and seems to have an association with the development of amyloidosis and the PFMS. The high frequency of V726A, and the unique high frequency of M694I in Arabs compared with 3 other ethnic groups, are confirmed.

Familial Mediterranean Fever and E148Q Pyrin Gene Mutation in Greece

Familial Mediterranean fever (FMF) is an inherited disease characterized by recurrent inflammatory polyserositis. Although FMF is classically expected only in Middle East populations, it is becoming evident that the disease affects more groups than initially thought. The disease is associated with a number of mutations of the MEFV gene, which codes for a protein named pyrin. The role of E148Q pyrin gene mutation in the development of FMF remains inconclusive. Some authors believe it causes the disease, whereas others favor the concept of a noncausative role. To understand better the role of this mutation, gathering data from different populations may be of value. We studied 60 Greek cases fulfilling the criteria for FMF diagnosis, 30 cases being a definite FMF diagnosis and 30 a probable diagnosis. Twenty-one of the patients, carried mutation E148Q. One was a homozygote (E148Q/E148Q), and 20 carried mutation E148Q in combination with other mutations (compound heterozygotes). In 6 of the 60 cases studied, no mutations were found. Compared with the results for healthy controls, E148Q mutation is significantly frequent. Because different populations may exhibit different patterns of pyrin mutations, association of the E148Q mutation with FMF should be considered in connection with origin data.

Reverse-Hybridization vs. DNA Sequencing in the Molecular Diagnosis of Familial Mediterranean Fever

Familial Mediterranean fever (FMF) is an autosomal recessive inflammatory disorder predominantly affecting people living in or originating from areas around the Mediterranean Sea. It is caused by a number of mutations within the MEFV gene, which differently affect the severity of the disease phenotype. Because patients usually present with rather nonspecific clinical symptoms, MEFV genotyping can confirm and refine FMF diagnosis and improve treatment of affected individuals. We have performed a method comparison study on 100 Lebanese FMF patients to evaluate the potential of a rapid reverse-hybridization teststrip-based assay (FMF StripAssay) to serve as a first-line screening test for our population. When results obtained by reverse-hybridization and DNA sequencing of exons 2, 3, 5, and 10 were compared, the FMF StripAssay identified 144/149 mutations, and correctly typed all 12 different MEFV mutations covered. We conclude that reverse-hybridization provides a very rapid, accurate and easy-to-perform screening method, and, in combination with more comprehensive diagnostic methods, represents an efficient strategy for FMF genotyping.

Amyloidosis in familial Mediterranean fever patients: correlation with MEFV genotype and SAA1 and MICA polymorphisms effects

Background

Familial mediterranean fever (FMF) is a recessively inherited disease characterized by recurrent crises of fever, abdominal, articular and/or thoracic pain. The most severe complication is the development of renal amyloidosis. Over 35 mutations have been discovered so far in the gene responsible for the disease, MEFV. This article aims at determining a correlation between the MEFV genotype and the occurence of amyloidosis in FMF patients, in addition to the study of the modifying effects of the SAA1 (type 1 serum amyloid A protein) and MICA (Major Histocompatibility Complex (MHC) class-I-chain-related gene A) genes on this severe complication.

Methods

Fourteen MEFV mutations were screened and the SAA1 and MICA polymorphisms tested in 30 FMF patients with amyloidosis and 40 FMF patients without amyloidosis.

Results

The M694V and V726A allelic frequencies were, respectively, significantly higher and lower in the group with amyloidosis, compared to the control FMF group. The beta and gamma SAA1 alleles were more frequently encountered in the group without amyloidosis, whereas the alpha allele was significantly more observed in FMF patients with amyloidosis (p < 0.025). All the MICA alleles were encountered in both patients' groups, but none of them was significantly associated with amyloidosis.

Conclusions

The results suggest a protective effect of the SAA1 beta and gamma alleles on the development of amyloidosis and show the absence of a MICA modifying effect on amyloidosis development. Testing these polymorphisms on a larger sample will lead to more definite conclusions.

Familial Mediterranean Fever: association of elevated IgD plasma levels with specific MEFV mutations

Familial Mediterranean Fever (FMF) is a recessively inherited disorder, characterized by episodic fever, abdominal and arthritic pain, as well as other forms of inflammation. Some FMF patients present higher IgD serum levels, and it is not yet known whether such an elevation is related to specific genotypes or correlated with a specific phenotype. In order to evaluate the association between known FMF-related mutations and IgD levels in confirmed patients, as well as the correlation between those levels and the presence of specific clinical signs, genotypic analysis and IgD plasma measurements were performed for 148 Lebanese and Jordanian FMF patients. Most common mutational patterns were M694V heterozygotes (19%) and homozygotes (17%), and V726A heterozygotes (18%) and homozygotes (5%), with an additional 11% combining both mutations. Twenty-one patients had higher IgD levels (superior to 100 microg/ml). The risk for higher IgD levels was significantly associated with M694V homozygote status (OR = 6.25) but not with heterozygotic one (OR = 1). Similarly, the risk for higher IgD was also found with V726A homozygotes (OR = 2.2) but not with heterozygotes (OR = 1.05). The use of colchicine was not statistically associated with IgD levels. Clinically, hyper IgD was also found significantly associated with arthritis (OR = 18). Thus, homozygotic status for M694V, and to a lesser extent V726A, is associated with increased risk for higher IgD plasma levels, regardless of colchicine use. Elevated IgD plasma levels are also correlated with the severity of FMF manifestations, and especially with arthritis.

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.