Familial Mediterranean Fever Associated withMEFVMutations in a Large Cohort of Cypriot Patients

Pyoderma gangrenosum in a patient with familial Mediterranean fever and chronic inflammatory seronegative arthropathy: a unique triad

Familial Mediterranean fever (FMF) is an autoinflammatory disorder characterised by recurrent fever attacks and serositis. Chronic inflammatory seronegative arthropathy affects the spine and peripheral joints and rarely coexists with FMF. Pyoderma gangrenosum (PG) is a neutrophilic dermatosis that manifests as an ulcerative skin disease that uncommonly occurs in patients with FMF. In this case report, we describe a male patient in his 60s with a history of FMF and chronic inflammatory seronegative arthropathy who developed ulcerative skin lesions consistent with PG. A genetic evaluation revealed a pathogenic variant (V726A) and two variants of uncertain significance (F479L and E167D) mutations in the MEFV gene. We hypothesised that the triad of FMF, chronic inflammatory seronegative arthropathy and PG might be linked to the V726A variant, while the presence of the other two variants may have amplified the clinical presentation. Further studies are warranted to confirm our observation.

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.

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.

MEFV c.2230G>T p.(Ala744Ser) rs61732874 previously misclassified as pathogenic variant due to lack of a population specific database

BACKGROUND

Familial Mediterranean fever is a hereditary inflammatory disorder caused by variants in MEFV. c.2230G>T p.(Ala744Ser) rs61732874 is considered to be an established pathogenic variant in MEFV, but in this study we provide a complete evaluation that suggests this variant is likely benign.

METHODS

Using an in-house exome database from 924 individuals, we extracted all individuals harboring this variant for clinical, laboratory, and familial evaluation.

RESULTS

We identified the variant in 58 individuals from 39 families. The allele frequency of this variant in our database is 4.2%. None of the identified individuals match the diagnosis of Familial Mediterranean Fever. Using the American College of Medical Genetics and Genomics guidelines for variant classification, this variant is classified as likely benign and not pathogenic.

CONCLUSION

Conflicting evidence about variants creates challenges for testing laboratories and impacts patient care. Sharing information drawn mainly from underrepresented populations and clinical phenotyping are important tools for precise curation of genetic variants.

Assessment of Epicardial Adipose Tissue Thickness in Children with Familial Mediterranean Fever

BACKGROUND

Familial Mediterranean fever (FMF) is suggested to be associated with increased risk of atherosclerosis. Epicardial adipose tissue (EAT) thickness is used in prediction of atherosclerotic risk. The aim of our study was to evaluate EAT thickness in FMF patients for early detection of risk of atherosclerosis and to be compared with its level in healthy controls.

METHODS

Thirty 6- to 18-year-old children with FMF and 30 age- and sex-matched children (control group) were included in the study. Disease characteristics, disease severity and Mediterranean fever gene mutations were recorded. EAT thicknesses was measured by echocardiography.

RESULTS

EAT in patients' group was significantly greater than that of controls (5.21 ± 2.3 vs. 2.81 ± 2.96 mm, p = 0.001) and was correlated with cholesterol level and platelets count (p = 0.047 and 0.018, respectively).

CONCLUSION

This study concluded that EAT thickness was statistically increased in FMF patients than controls with a positive correlation with cholesterol level and platelet count. This finding suggests a higher risk for atherosclerosis in these patients. Follow-up study is needed to verify the effect of treatment of FMF on the EAT thickness. Further studies with larger number of patients following-up EAT are needed to verify this finding.

A novel cluster of patients with Familial Mediterranean Fever (FMF) in southern Italy

BACKGROUND

Familial Mediterranean Fever (FMF) is an autosomal recessive autoinflammatory disorder characterised by recurrent attacks of fever and serositis (peritonitis, pleuritic or synovitis) affecting mainly populations of Mediterranean origin.

AIM

To describe a relatively new cluster of FMF subjects from Apulia and Basilicata regions (southern Italy).

PATIENTS AND METHODS

Subjects were screened for FMF using the Tel-Hashomer criteria and genetic analysis. Demographic data were taken from patients' files and direct interviews. Patients were investigated about attack duration, intensity and site, body temperature, skin manifestations and overall quality of life before and after treatment with colchicine. Inflammatory parameters were also measured between these periods.

RESULTS

Forty-nine subjects had FMF (M : F = 26 : 23, age 38 years ± 2 SE) and followed-up up to 8 years. The age at disease onset was 22·1 years ± 1·2SE and the diagnostic delay was 15·5 years ± 1·9SE. The majority of patients (82%) suffered from abdominal pain, and 35% had undergone prior abdominal surgery or laparotomy. Severity score (ISSF) was mild in 43% of patients and intermediate in 57% of patients. Serum amyloid A (SAA) was increased in 20% of patients (16·9 ± 3·7, normal range < 6·4 mg/dL). In over 95% of patients, inflammation markers, duration and intensity of febrile painful attacks, quality of life and ISSF score improved dramatically following colchicine treatment.

CONCLUSION

The Apulia region represents a new endemic area for FMF. Clinical presentation of FMF can be misleading and requires a complete and early workup to recognise the disease and avoid unjustified surgery. Colchicine remains the gold standard therapy to prevent FMF attacks and fatal long-term complications.

Evidence of digenic inheritance in autoinflammation-associated genes

Familial Mediterranean fever (FMF) has traditionally been considered as a monogenic autosomal recessive disorder caused by mutations in the MEFV gene with highest incidence among Mediterranean populations. In a considerable number of patients with typical FMF, only one MEFV mutation was identified and the possibility that more than one autoinflammatory gene may be responsible for their disease was investigated. In the present study, an extensive search for possible mutations in three hereditary recurrent fever (HRF) genes was performed in 128 MEFV heterozygous Greek-Cypriots clinically diagnosed based on their phenotype with FMF-like disease from a previous study. Sequence analysis was performed for MVK, TNFRSF1A and NLRP3 genes which is also known to cause HRFs. In total, three patients were identified with heterozygous mutations and a second mutation in an autoinflammatory gene. Two patients carried a MEFV mutation and a NLRP3 mutation, and an additional third carried a MEFV mutation and a TNFRSF1A mutation. Patient 1 carried MEFV p.[Val726Ala] (NM_000243.2:c.2177T>C) and NLRP3 p.[Val198Met] (NM_001243133.1:c.592G>A) variants and patient 2 carried MEFV p.[Glu148Gln] (NM_000243.2:c.442G>C) variant which is of uncertain significance and NLRP3 p.[Arg176Trp] (NM_001243133.1:c.526C>T). Lastly, patient 3 was identified to carry MEFV p.[Met694Val] (NM_000243.2:c.2080A>G) and TNFRSF1A p.[Arg121Gln] (NM_001065.3:c.362G>A) variants. The results from this study indicate that screening of genes known to cause HRFs in patients already identified with a single MEFV mutation, can reveal quite rare but potentially causative mutational combinations at different loci. Such interaction provide further evidence for possible locus-locus interactions and phenotypes resulting from digenic inheritance.

Prevalence of Mediterranean FeVer Gene Mutations in Turkish Cypriot Population

Objectives

This study aims to determine the carrier frequency and the most common mutations of the Mediterranean FeVer (MEFV) gene in healthy Cypriot population of Turkish origin.

Patients and methods

A total of 296 healthy participants (102 males, 194 females; median age 30 years; range 1 to 81 years) were evaluated. The exon 2, 3, 5 and 10 of MEFV genes were amplified by polymerase chain reaction.

Results

The participants demonstrated an extremely high carrier rate (12.5%). Most commonly detected mutations were E148Q and A74S, with rates of 7.3% and 2.8%, respectively.

Conclusion

Mediterranean FeVer gene mutation types and carrier rates in Turkish Cypriot population are different than other Mediterranean populations in the region. MEFV mutation carriage is frequent in North Cyprus and familial Mediterranean fever might be one of the causes for end stage renal disease in Turkish Cypriots.

A Rare Coincidence of Sitosterolemia and Familial Mediterranean Fever Identified by Whole Exome Sequencing

Whole exome sequencing (WES) technologies have accelerated genetic studies of Mendelian disorders, yielding approximately 30% diagnostic success. We encountered a 13-year-old Japanese female initially diagnosed with familial hypercholesterolemia on the basis of clinical manifestations of severe hypercholesterolemia (initial LDL cholesterol=609 mg/dl at the age of one) and systemic intertriginous xanthomas with histories of recurrent self-limiting episodes of fever and arthritis. Both her phenotypes seemed to co-segregate in a recessive manner. We performed WES on this patient, who was considered a proband. Among 206,430 variants found in this individual, we found 18,220 nonsense, missense, or splice site variants, of which 3,087 were rare (minor allele frequency ≤ 0.01 or not reported) in 1000 Genome (Asian population). Filtering by assuming a recessive pattern of inheritance with the use of an in silico annotation prediction tool, we successfully narrowed down the candidates to the compound heterozygous mutations in the ABCG5 gene (c.1256G＞A or p.Arg419His/c.1763-1G＞A [splice acceptor site]) and to the double-compound heterozygous mutations in the MEFV gene (c.329T＞C/C or p.Leu110Pro/c.442G＞C/C or p.Glu148Val). The patient was genetically diagnosed with sitosterolemia and familial Mediterranean fever using WES for the first time. Such a comprehensive approach is useful for identifying causative mutations for multiple unrelated inheritable diseases.

Near East University Genetic Mutation Database (NEU-GD): The first mutation database of Northern Cyprus

The health care system is negatively affected by the genetic disorders that lead to an increasing rate of morbidity and neonatal deaths and affect adults as well. These create a substantial government's psychosocial and economic burden on clinicians, patients and their families with the advancement in the field of genetics. There has been a tremendous increase in the rate in which diseases associated with variant DNA sequences are being sought and identified. The goal behind the creation of Near East University Genetic Mutation Database (NEU-GD) is to map and apprehend the patterns of common genetic diversity in the human genetic makeup in order to accelerate the search for the genetic causes of human disease. NEU-GD will allow scientists to generate extraordinarily useful information such as allelic variations among population, and description of the genetic blueprint of mutations occurring in human beings. In this communication we report the construction of the first genetic mutation database for the people belonging to different ethnic groups living in North Cyprus (http://genetics-db.neu.edu.tr/). Therefore NEU-GD can serve as an important tool available online for molecular genetic testing of inherited disorder and persuade for further investigation of novel genetic disorders in North Cyprus population.

Global epidemiology of Familial Mediterranean fever mutations using population exome sequences

Familial Mediterranean fever (FMF) is an inherited disorder characterized by recurrent episodes of fever accompanied by sterile peritonitis, arthritis, and pleuritis. Many mutations in the MEFV gene have been identified as causing FMF. However, accompanying epidemiological information remains quite scarce except in some Mediterranean countries, and the degree of penetrance has been a subject of controversy. Here, I established a genetic epidemiology of full FMF mutations using two population exome studies. Of 57 mutations associated with FMF, 22 were detected in a total of 9007 individuals from two exome sequences. Exome-based epidemiology revealed the carrier rates of FMF in 28 populations in 19 countries by individual mutation and showed strong population specificity for the MEFV mutations. Unexpectedly high carrier rates suggested that some mutations are benign variants with no pathological significance and highlighted the need for caution in analyzing MEFV mutations. Similar approach could be used to uncover the incomplete or no penetrance of mutations in most inherited disorders.