MEFV heterogeneity in Turkish Familial Mediterranean Fever patients

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

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

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.

Is Turkish MEFV Mutations Spectrum Different Among Regions?

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The role of IL-4 gene 70 bp VNTR and ACE gene I/D variants in Familial Mediterranean fever

Familial Mediterranean fever (FMF) is characterized by recurrent attacks of fever and inflammation in the peritoneum, synovium, or pleura, accompanied by pain. It is an autosomal recessive disease caused by mutations in the MEFV (MEditerranean FeVer) gene. Patients with similar genotypes exhibit phenotypic diversity. As a result, the variations in different genes could be responsible for the clinical findings of this disease. In previous studies genes encoding Angiotensin-Converting Enzyme (ACE) and IL-4 (Interleukin-4) were found to be associated with rheumatologic and autoimmune diseases. In the present study we hypothesized whether ACE I/D or IL-4 70 bp variable tandem repeats (VNTR) genes are associated with FMF and its clinical findings in Turkish patients. Genomic DNA obtained from 670 persons (339 patients with FMF and 331 healthy controls) was used in the study. Genotypes for an ACE gene I/D polymorphism and IL-4 gene 70 bp VNTR were determined by polymerase chain reaction with specific primers. To our knowledge, this is the first study examining ACE gene I/D polymorphism and IL-4 gene 70 bp VNTR polymorphism in FMF patients. As a result, there was a statistically significant difference between the groups with respect to genotype distribution (p<0.001). According to our results, ACE gene DD genotype was associated with an increased risk in FMF [p<0.001; OR (95%): 7.715 (4.503-13.22)]. When we examined ACE genotype frequencies according to the clinical characteristics, we found a statistically significant association between DD+ID genotype and fever (p=0.04). In addition IL-4 gene P1P1 genotype was associated with FMF (p<0.001). We propose that D allele or DD genotype of ACE gene and P1 allele or P1P1 genotype of IL-4 gene may be important molecular markers for susceptibility of FMF.

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

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

Prevalence of known mutations and a novel missense mutation (M694K) in the MEFV gene in a population from the Eastern Anatolia Region of Turkey

Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent attacks of fever and serositis. Mutations in the Mediterranean fever gene (MEFV) localized on the short arm of chromosome 16 cause FMF. Over 90 MEFV missense/nonsense mutations have been identified so far in FMF patients, mostly in the 10th exon of the gene. In this study, the molecular test results of 891 patients identified as having FMF clinical symptoms referred to Molecular Genetics Laboratory of the Department of Medical Biology and Genetics, Faculty of Medicine, Inonu University, Malatya/Turkey were retrospectively evaluated. Patients were referred by their physicians for MEFV mutation detection. The DNA fragments including hot spots within the coding sequences of the MEFV gene were amplified by PCR using genomic DNA and analyzed by pyrosequencing technique. Of the 891 patients investigated, 420 (47.13%) had at least one mutation. The most frequent mutation was E148Q, followed by M694V, M680I (G/C), P369S, V726A, R761H, A744S, M694I, K695R and F479L mutations. In addition, a novel missense mutation (M694K) was reported in seven members of a family in the course of mutation screening of patients.

Familial Mediteranean fever with protein-losing enteropathy due to constrictive pericarditis

BACKGROUND

Constrictive pericarditis (CP) represents a rare cause of protein-losing enteropathy (PLE) resulting from intestinal lymphangiectasia (IL). In this report, we describe an 8-year-old Turkish boy with IL and PLE secondary to CP.

METHODS

The boy was introduced to our clinic due to bilateral pretibial edema and swelling of the eyelids caused by hypoproteinemia. Physical examination revealed a distended right jugular vein. Laboratory investigation revealed PLE with fecal concentration of alpha-1 antitripsin of 4.87 mg/g. Histopathologic examination of random biopsies obtained from the duodenum revealed markedly dilated lymphatics compatible with IL. Constrictive pericarditis was diagnosed by tagged cine cardiac magnetic resonance imaging.

RESULTS

Pericardiectomy was performed for the patient. Genetic analysis was done and heterozygous mutation E148Q was detected as a disease-causing Mediterranean fever (MEFV) mutation. Colchicine was started after the operation. Six months after the initiation of regular colchicine therapy, echocardiography revealed disappearance of CP.

CONCLUSION

This is the first reported case of PLE with a distended right jugular vein due to CP secondary to familial Mediterranean fever associated with E148Q heterozygosity in the MEFV gene.

Familial mediterranean Fever: a retrospective clinical and molecular study in the East of anatolia region of Turkey

Familial Mediterranean Fever (FMF) is an autoinflammatory periodic disorder. We aim to identify the distribution and the frequency of the Mediterranean Fever (MEFV) gene mutations in the east of Anatolia in Turkey and perform a genotype/phenotype correlation in the patients’ cohort. The study was carried out on 415 clinically diagnosed Turkish FMF patients and 103 healthy controls. The tested individuals were screened for the most common twelve MEFV mutations. The most important features were the predominance of the M694V and E148Q mutations in patient group and the earlier of onset of the disease in M694V mutation carriers compared with the carriers of other mutations (P=0.00). We discuss the high frequency of E148Q mutations in patient group compared with controls, genetic counseling in intermarriage families and the variations in mutation frequency according to regions of Turkey.