Significance of MEFV gene R202Q polymorphism in Turkish familial Mediterranean fever patients

Objective

Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent attacks of fever and inflammation in the peritoneum, synovium, or pleura, accompanied by pain. The disease is associated with mutations in the Mediterranean fever (MEFV) gene, which encodes for the pyrin protein. The aim of this study was to explore the frequency and clinical significance of the R202Q (c.605G>A) polymorphism in exon 2 of the MEFV gene in a cohort of Turkish patients with FMF.

Methods

The study included 191 patients with FMF and 150 healthy controls. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay for the MEFV gene R202Qpolymorphism.

Results

The genotype and allele frequencies of R202Q polymorphism showed a statistically significant difference between FMF patients and controls (p < 0.0001 and p = 0.0004, respectively) and especially the homozygous AA genotype was significantly higher in FMF patients than healthy controls (p = 0.0002; odds ratio = 6.27; 95% CI = 2.1–18.3). However no significant association was observed between clinical and demographic features of FMF patients and R202Qpolymorphism.

Conclusion

The results of this study showed that there was a high association between MEFV gene R202Q polymorphism and FMF. R202Q polymorphism should be included in routine molecular diagnosis of FMF patients.     

Clinical and molecular analysis of common MEFV gene mutations in familial Mediterranean fever in Sivas population

Familial Mediterranean fever (FMF) is the most frequent hereditary inflammatory disease characterized by self-limited recurrent attacks of fever and serositis. The aim of the current study is to determine the frequency of the mutations in 365 suspected FMF patients and to reveal whether there is a correlation between genotype and phenotype of these patients. All patients were clinically examined according to Tell-Hashomer FMF criteria and were screened genetically in terms of common 12 Mediterranean fever gene (MEFV) mutations. Various point mutations were detected in 270 (74%) patients. The most frequent mutation was M694V (26.85% of the alleles) and was followed by E148Q (15.55%), M680I (G/C) (9.62%) and V726A (7.96%). Patients who bear M694V homozygous mutation had most severe disease phenotype and high risk for amyloidosis (P = 0.04). Our results indicate that Sivas population has a wide range of heterozygous mutated carriers of MEFV gene and there is a high frequency of E148Q allele when compared to the other Mediterranean groups.     

Prevalence and distribution of MEFV mutations among Arabs from the Maghreb patients suffering from familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessive inherited disease caused by mutations in MEFV. This disease is characterized by recurrent episodes of fever accompanied with topical signs of inflammation. Some patients can develop renal amyloidosis. We prospectively investigated MEFV mutations in a cohort of 209 unrelated Arab patients from Maghreb (85 Algerians, 87 Moroccans, and 37 Tunisians) with a clinical suspicion of FMF. FMF is the main cause of periodic fever syndrome in Maghreb. The most frequent MEFV mutations in this cohort were M694V and M694I. These mutations account for different proportions of the MEFV mutations in Algeria (5%, 80%), Morocco (49%, 37%), and Tunisia (50%, 25%) patients. M694I mutation is specific to the Arab population from Maghreb. Other rare mutations were observed: M680L, M680I, A744S, V726A, and E148Q. We estimated the frequency of MEFV mutation carriers among the Arab Maghrebian population at around 1%, which is significantly lower than in non-Ashkenazi Jews, Armenians or Turks.     

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 K?r?kkale 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.     

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.     

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 Cukurova 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.     

Regulation of cryopyrin/Pypaf1 signaling by pyrin,the familial Mediterranean fever gene product

Cryopyrin, a member of the Nod protein family mutated in familial cold urticaria and Muckle-Wells syndrome, has been recently implicated in inflammation. However, the mechanism of activation and regulation of the cryopyrin signaling pathway remains poorly understood. We report here that co-expression of cryopyrin with its binding partner, ASC, induced both apoptosis and NF-kappaB activation. This signaling was mimicked by oligomerization of ASC, suggesting that cryopyrin activates downstream targets as reported for other Nod family members. Notably, pyrin, the product of the familial Mediterranean fever gene, inhibited cryopyrin-mediated apoptosis and NF-kappaB activation by disrupting the cryopyrin-ASC interaction. These results provide evidence for a cryopyrin signaling pathway activated through the induced proximity of ASC, which is negatively regulated by pyrin.     

A new species of Acanthophyllum (Caryophyllaceae) from Central Anatolia, Turkey

A new species is described and illustrated from Central Anatolia: Acanthophyllum oppositiflorum Aytaç.     

Sex ratio of a population of Anatolian ground squirrelsSpermophilus xanthoprymnus in Central Anatolia, Turkey

We studied the sex ratio of a population of Anatolian ground squirrels,Spermophilus xanthoprymnus (Bennett, 1835), living in a steppe area about 50 km south of Ankara, Central Anatolia, Turkey in 1999–2001. The sex ratio among juveniles and yearlings did not differ from 1∶1, but the sex ratio among adults (≥ 2 years old) was biased toward females. We concluded that from their second summer of life as yearlings onwards, males experienced higher mortality than did females. Such higher mortality is common in ground squirrels, and is likely due to the risks encountered when males disperse from their natal areas.     

Genotype-phenotype correlation in Japanese patients with familial Mediterranean fever: differences in genotype and clinical features between Japanese and Mediterranean populations

Introduction

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized by recurrent self-limiting fever and serositis that mainly affects Mediterranean populations. Many patients with FMF have been reported in Japan due to increasing recognition of this condition and the availability of genetic analysis for the gene responsible, MEFV. The present study was performed to elucidate the clinical characteristics of Japanese FMF patients and to examine the precise genotype-phenotype correlation in a large cohort of Japanese FMF patients.

Methods

We analyzed the MEFV genotypes and clinical manifestations in 116 patients clinically diagnosed as having FMF and with at least one mutation.

Results

The most frequent mutation in Japanese patients was E148Q (40.2%), followed by M694I (21.0%), L110P (18.8%), P369S (5.4%), and R408Q (5.4%). In contrast, common mutations seen in Mediterranean patients, such as M694V, V726A, and M680I, were not detected in this population. The clinical features with M694I were associated with more severe clinical course compared to those seen with E148Q. P369S/R408Q showed variable phenotypes with regard to both clinical manifestations and severity. Patients with M694I showed a very favorable response to colchicine therapy, while those with P369S and R408Q did not.

Conclusions

Clinical features and efficacy of treatment in Japanese FMF patients vary widely according to the specific MEFV gene mutation, and therefore genetic analysis should be performed for diagnosis in cases of Japanese FMF.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-014-0439-7) contains supplementary material, which is available to authorized users.     

Serum amyloid A and P protein genes in familial Mediterranean fever

Two recent studies have suggested the involvement of serum amyloid A (SAA) and P (APCS) genes in familial Mediterranean fever (MEF). To test the role of SAA and APCS in MEF and MEF-amyloidosis, we studied 17 informative families (15 Armenians, 2 non-Ashkenazi Jews) and 8 MEF patients with amyloidosis using a candidate gene approach. No evidence for any MEF-associated polymorphism was found in any of the 41 Armenian and Jewish MEF patients tested. Our family studies allowed us to rule out tight linkage between SAA and MEF (lod score = -2.16, theta less than or equal to 0.06). For APCS we found that the allele frequency in the MEF-amyloidosis patients was similar to that in 18 unrelated MEF patients without amyloidosis and their 33 healthy parents. Finally, we excluded close genetic linkage between APCS and MEF at 8.5 cM or less (lod score = -2.2).     

Heightened endotoxin susceptibility of monocytes and neutrophils during familial Mediterranean fever

Familial Mediterranean fever (FMF) is a relapsing autoinflammatory disorder, caused by various mutations in the MEFV gene, which encodes a protein called pyrin, expressed in neutrophils and activated monocytes. Induction of monocyte endotoxin tolerance is observed in FMF patients during attack, whereas monocytes from patients in the attack-free period failed to induce lipopolysaccharide tolerance and exhibited heightened sensitivity to bacterial endotoxin. In this study, we demonstrated that impaired lipopolysaccharide tolerance induction in attack-free FMF patients correlates with both increased lipopolysaccharide-induced proinflammatory cytokine synthesis polarization and a different time-course pattern of lipopolysaccharide-induced changes on monocytic surface expression of CD14 and CD11b coreceptors. We found that this pattern is characterized either by delayed turnover of CD14 or increased surface retention of CD11b receptors on monocytes during stimulation with lipopolysaccharide. In addition, enhancement of lipopolysaccharide-induced apoptosis of neutrophils was observed in FMF patients, and was confirmed based on the fact that neutrophils from FMF patients previously unexposed to Salmonella enteritidis exhibited heightened susceptibility to the lipopolysaccharide of this pathogen similar to that of patients infected with this species.     

Exclusion of linkage between familial Mediterranean fever and the human serum amyloid A (SAA) gene cluster

Summary We studied the relationship between the autosomal recessive trait familial Mediterranean fever (FMF) and the serum amyloid A (SAA) genes by comparing alleles of a highly polymorphic dinucleotide repeat and a conventional restriction fragment length polymorphism (RFLP) in the SAA gene cluster in Israeli FMF kindreds. By haplotype analysis, our data indicate a minimum crossover frequency of 22% between the SAA gene marker and FMF. By conventional linkage analysis this eliminates a minimum of 10.4cM including and surrounding the SAA gene cluster as the site of the FMF mutation although SAA proteins are prominent physiologic markers of the acute attacks.     

Study of the mutation M694V of familial Mediterranean fever in Jews

Familial Mediterranean fever (FMF) is a recessively inherited disorder characterized by episodes of fever with abdominal pain, pleurisy, or arthritis. The familial Mediterranean fever gene, designated MEFV, was recently cloned, and the missense mutation M694V accounting for most of the patients with this disease was identified. The objective of the present study was to establish frequencies of the M694V mutation in three groups of Jews. The subjects studied were 381 Sephardi, 256 Ashkenazi, and 65 Oriental Jews, all male subjects, previously collected for an anthropological study, independent of their FMF status. The M694V mutation in the 702 samples was assessed by amplifying genomic DNA with the use of primers that selectively amplify the normal or altered DNA sequence of the M694V mutation, by the amplification refractory mutation system (ARMS). In our sample of Sephardi Jews, the frequency of the M694V mutation is elevated (10.9%), and this is also the case for Oriental Jews (9.2%). In our sample of Ashkenazis, the M694V allele frequency is very low (0.8%).     

Ethnobotanical aspects of some taxa in east Anatolia, Turkey

This paper presents a list of some medicinal plants distributed in the East Anatolia region. The list was prepared during an ethnobotanical survey of the region from 1995 to 2002. East Anatolia has a rich flora due to its variable climate and its many ecological zones. This diversity in flora provides a rich source of medicinal plants that has been long utilized by Anatolian cultures; and hence, accounts for the remarkable accumulation of medicinal folk knowledge for the region. This paper provides information about 71 useful plants grown in the region, 20 of which are reported for the first time. In addition to the scientific names, vernacular names and medicinal uses are given for each plant.     

Oxidative DNA damage in polymorphonuclear leukocytes of patients with familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessively inherited disorder characterized by recurrent, inflammatory self-limited episodes of fever and other symptoms. This disease is caused by more than 25 mutations in the gene MEFV. During fever attacks, there is a substantial influx of polymorphonuclear leukocytes into the affected tissues. Attack-free periods are accompanied by the up-regulation of neutrophil and monocyte phagocytic activity and oxidative burst. These facts led us to hypothesize that oxidative damage by free radicals to DNA may accumulate in FMF patients. To test this hypothesis, we investigated oxidative DNA damage in polymorphonuclear leukocytes of FMF patients during the attack-free period in comparison with FMF-free control individuals. DNA was isolated from polymorphonuclear leukocytes of 17 FMF patients and 10 control individuals. DNA samples were analyzed by liquid chromatography/mass spectrometry and gas chromatography/mass spectrometry to measure the levels of various typical oxidatively induced products of DNA. We show, for the first time, that FMF patients accumulate statistically significant levels of these lesions in their DNA when compared to FMF-free control individuals. This work suggests that the persistent oxidative stress with excess production of free radicals in FMF patients may lead to accumulation of oxidative DNA damage. Defective DNA repair may also contribute to this phenomenon, perhaps due to mutations in the MEFV gene. The accumulation of mutagenic and cytotoxic DNA lesions may contribute to increased mutations and apoptosis in FMF patients, thus to worsening of the disease and well-being of the patients. Future research should deal with prevention of oxidative DNA damage and apoptosis in FMF patients, and also the elucidation of a possible role of DNA repair in this disease.