Colitis in a patient with familial Mediterranean fever: Is it Crohn's disease or ulcerative colitis?

A 24-year-old woman was referred to our hospital with joint pain, fever, abdominal pain, and diarrhea. A colonoscopy revealed longitudinal ulcers with a cobblestone appearance throughout the entire colon, suggestive of Crohn's disease. However, treatment with 5-aminosalicylic acid, azathioprine, and infliximab failed to achieve clinical remission. A colonoscopy 5 months later revealed a diffusely spreading granular mucosa without visible vasculature, compatible with active ulcerative colitis. Based on these serial changes in colonic lesions, we tested the patient for MEFV gene mutations and found variants E148Q and L110P in exon 2. Administration of colchicine resulted in complete clinical remission. Our experience suggests that drastic changes in the features of colonic inflammation may be a clue to the diagnosis of enterocolitis associated with familial Mediterranean fever.

Implementation of long-read sequencing for routine molecular diagnosis of familial mediterranean fever.

Background: Long-read sequencing technology, widely used in research, is proving useful in clinical diagnosis, especially for infectious diseases. Despite recent advances, it hasn't been routinely applied to constitutional human diseases. Long-read sequencing detects intronic variants and phases variants, crucial for identifying recessive diseases. Methods: We integrated long-read sequencing into the clinical diagnostic workflow for the MEFV gene, responsible for familial Mediterranean fever (FMF), using a Nanopore-based workflow. This involved long-range PCR amplification, native barcoding kit library preparation, GridION sequencing, and in-house bioinformatics. We compared this new workflow against our validated method using 39 patient samples and 3 samples from an external quality assessment scheme to ensure compliance with ISO15189 standards. Results: Our evaluation demonstrated excellent performance, meeting ISO15189 requirements for reproducibility, repeatability, sensitivity, and specificity. Since October 2022, 150 patient samples were successfully analyzed with no failures. Among these samples, we identified 13 heterozygous carriers of likely pathogenic (LP) or pathogenic (P) variants, 1 patient with a homozygous LP/P variant in MEFV, and 4 patients with compound heterozygous variants. Conclusion: This study represents the first integration of long-read sequencing for FMF clinical diagnosis, achieving 100 % sensitivity and specificity. Our findings highlight its potential to identify pathogenic variants without parental segregation analysis, offering faster, cost-effective, and accurate clinical diagnosis. This successful implementation lays the groundwork for future applications in other constitutional human diseases, advancing precision medicine.

Interleukin-21 and Interleukin-23 levels in familial Mediterranean Fever before and after treatment: the role of cytokines in disease pathogenesis.

In a previous study, it has been shown that the population of Th17 lymphocytes was increased in patients with FMF. IL-21 and IL-23 play significant roles in the production and differentiation of Th17 cells. In this study, we aimed to evaluate serum levels of IL-21 and IL-23 in FMF patients both at diagnosis and after treatment, and to compare these levels with those of healthy controls. Twenty-seven newly diagnosed patients with FMF in attack-free periods and twenty-seven healthy volunteers enrolled in the study. The groups were comparable with respect to age and gender. IL-21 and IL-23 levels in serum samples from patients at the time of diagnosis, in remission after treatment, and from the control groups were analysed using the ELISA method. There was no significant difference between the cytokine levels of the patient group at the time of diagnosis and the cytokine levels of the control group (for IL-21, p: 0.28 and for IL-23, p: 0.56). Similarly, there was no significant difference between the patients' cytokine levels at the time of diagnosis and after treatment (for IL-21, p: 0.99 and for IL-23, p: 0.08). Interleukin levels at the time of diagnosis did not differ among patient groups based on the presence of clinical findings or the M694V genotype. Our results suggest that IL-21 and IL-23 do not play a role in the pathogenesis of the disease. However, while interpreting these findings, it should be considered that patients with active episodes were excluded and cytokine levels were not measured in tissue samples.

Pregnancy occurring in AA amyloidosis: a series of 27 patients including 3 new French cases.

BACKGROUND: AA amyloidosis (AAA) is a multisystem disease related to the deposition in tissues of serum amyloid A protein which complicates chronic inflammation. It is a potentially fatal complication.  Renal involvement is the most common manifestation of AAA. Pregnancy in women with chronic kidney disease  is considered to be at risk for specific pregnancy complications and the worsening of their underlying renal dysfunction. Our aim was to report pregnancy in our AAA patients and discuss the outcome through a literature review. METHODS: French cases were identified through the Reference Center for Auto-Inflammatory Diseases and Amyloidosis and a systematic literature review was performed. RESULTS: Three new patients were identified: two with Familial Mediterranean fever (FMF) and one with cryopyrin-associated periodic syndrome; one was under anakinra therapy and one had received a kidney transplantation before her pregnancy. One patient was diagnosed with AAA following the detection of post-partum nephrotic syndrome. Among the 27 patients from literature and our case, FMF was the main cause of AAA (69%). Eight of the patients were diagnosed with AAA during their pregnancy or in immediate post-partum and gestational complications appeared in 23/25 cases, mostly intrauterine growth retardation (n = 10), prematurity (n = 11) and preeclampsia (n = 4). No bleeding complication was reported. CONCLUSION: Pregnancy can occur in patients (eight overall) with AAA and the diagnosis is frequently made during pregnancy. Pregnant women with AAA are at risk for adverse pregnancy-associated outcomes and require special and closer monitoring.

Heterozygous MEFV Mutation Leading to Renal Failure: A Case Study.

Familial Mediterranean fever (FMF) is an autosomal recessive disorder, particularly common in the Mediterranean area. Mutations in the MEVF gene cause it. AA Amyloidosis is the most severe complication of FMF leading to chronic renal failure. We describe a rare pediatric case of a phenotype I familial Mediterranean fever with V726A heterozygous mutation. The diagnosis was made at chronic kidney disease. We discuss through this case the importance of the early diagnosis of FMF heterozygous children which is not usually evident in some phenotypes. It will surely avoid fatal complications, inappropriate therapeutic approaches and higher healthcare costs.

The Potential Role of Cell-Death Mechanisms in the Pathogenesis of Familial Mediterranean Fever Attacks: Granzyme A and Beyond.

BACKGROUND: FMF is the most common autoinflammatory disease. The activation of the pyrin inflammasome is the mainstay of the pathogenesis, which might lead to a specific cell-death mechanism, pyroptosis. Pyroptosis is a programmed inflammatory cell death mediated by gasdermin proteins, featuring cell swelling, membrane rupture, and release of inflammatory contents Aim: In this study we aimed to analyze the cell-death mechanisms in the pathogenesis of FMF attacks. METHODS: Twenty-five FMF patients were included, and PFAPA patients (n = 10) and healthy controls (HC, n = 10) served as controls. We collected plasma samples from FMF and PFAPA patients during the attack and the attack-free period. We measured the soluble plasma levels of sFas, sFasL, granzyme A, granzyme B, perforin, granulysin, IL-2, IL-4, IL-10, IL-6, IL-17A, TNF-α, and IFN-γ by commercial pre-defined cytometric bead array kits. RESULTS: There was no significant difference between groups in terms of sex and age between FMF patients and HCs, but PFAPA patients were younger than other groups due to the nature of the disease. We then analyzed the components of apoptosis and pyroptosis. The levels of sFasL (p = 0.035) and granzyme A (p = 0.038) in FMF patients were significantly increased during the attack period and decreased to levels comparable to HCs during the attack-free period. This increase was not seen in the PFAPA patients, with comparable levels with the HC group both during attack period and attack-free period. During the attack period of FMF patients, granzyme B (p = 0.145) and perforin (p = 0.203) levels were also increased; however, the differences were not statistically significant. The levels of sFasL, granzyme A, granzyme B, and perforin were closely correlated with each other during the attack period of FMF patients. CONCLUSIONS: Our study on death pathways during an FMF attack, suggests an upregulation in both pyroptosis through the granzyme-gasdermin pathway and apoptosis with the increased FasL and perforin levels, which was different from PFAPA patients. These findings might shed light on the reason for the nature of self-limited attacks, but further studies are needed to prove this hypothesis.

Diagnostic delays in familial Mediterranean fever: a Juvenile Inflammatory Rheumatism (JIR) cohort study.

Several studies reported that Familial Mediterranean Fever (FMF) diagnosis may be missed or delayed even in countries with a high FMF prevalence. Our aim was to study on a large cohort of European FMF patients the frequency and associated factors of diagnosis delay. Clinical data were extracted from the Juvenile Inflammatory Rheumatism (JIR)-cohort. All FMF patients fulfilled Livneh Criteria and had been sequenced for MEFV exon 10. FMF-diagnostic delay (d-FMF) was defined as the duration between the onset of the symptoms and the diagnosis of more than 10 years. 960 FMF patients were enrolled: delayed diagnosis (d-FMF) was noted in 200 patients (20%). d-FMF patients were significantly older compared to non d-FMF with a median age of 46.4 years old vs. 15.5 (p < 0.0001). Women displayed more d-FMF compared to men (56 vs. 47%, p = 0.03). Clinical presentation during attacks was not statistically significant except for erysipelas-like erythema, which was higher among d-FMF patients (33 vs. 22%, p = 0.0003). The presence of one or two pathogenic MEFV mutation was not different between patients. Compared to other FMF, d-FMF patients displayed significantly more AA amyloidosis (10 vs. 2.6%, p < 0.0001) and received more biotherapy (18 vs. 3.8%, p < 0.0001). Twenty percent of FMF patients had a diagnostic delay >10 years, including more women. The differential diagnosis of abdominal attacks with menstrual pain may be an explanation, and erysipelas-like erythema may not be recognized as FMF by all practitioners.

Successful Management of Pyoderma Gangrenosum in a Patient With Concurrent Behçet's Disease and Familial Mediterranean Fever: A Case Report.

Pyoderma gangrenosum (PG) is a rare ulcerative skin condition. Familial Mediterranean fever (FMF) and Behçet's disease (BD) are autoinflammatory disorders common in Mediterranean populations. The coexistence of FMF and BD is unusual, and the presence of PG alongside both is even rarer. We present a case of a 51-year-old male diagnosed with both BD and FMF who developed PG during treatment. His PG lesion was managed with a tailored regimen that included topical hydrocortisone acetate with fusidic acid, colchicine, topical tacrolimus, oral prednisone, and intravenous infliximab, which led to the successful healing of the PG lesion. This case underscores the need for specialized approaches to manage overlapping autoinflammatory conditions.

The Role of Tenascin-C in the Physiopathology of Familial Mediterranean Fever.

OBJECTIVE: Familial Mediterranean fever (FMF) is an autoinflammatory disease common in the Mediterranean basin. It has been determined that tenascin-C level is increased in rheumatic inflammatory diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus, and systemic sclerosis. However, the role of tenascin-C has not been investigated in FMF. This study aimed to investigate serum tenascin-C levels in FMF patients and to investigate possible relationships between them. MATERIALS AND METHODS: About 38 patients diagnosed with FMF and 40 healthy controls were included in the study. The patient's sex, age, clinical symptoms, physical examination, and laboratory results were recorded. Serum tenascin-C levels were determined by the enzyme-linked immunosorbent assay (ELISA) method. RESULTS: The serum tenascin-C levels were significantly lower in the FMF patients (10297 ± 8107 pg/ml) compared to the healthy control group (29461 ± 13252 pg/ml) (p < 0.001). In receiver operating characteristic (ROC) analysis, when the cut-off point was chosen as 11076 pg/ml, sensitivity was 77.1% and specificity was 91.9%. When the cut-off point was chosen as 19974 pg/ml, sensitivity was 91.4% and specificity was 75.7%. It was determined that the serum tenascin-C levels did not correlate with age, gender, and laboratory parameters in the healthy control group and FMF patients (p > 0.05). CONCLUSION: This is the first study investigating tenascin-C levels in FMF. Tenascin-C levels in FMF patients were lower than in healthy controls. Low tenascin-C levels in FMF, which are high in other chronic rheumatic diseases, may be a valuable indicator. Therefore, serum tenascin-C level seems to be a useful marker in distinguishing FMF patients from healthy individuals.

Severity scores, damage indices and the concept of the colchicine-resistant patient in familial Mediterranean fever.

Familial Mediterranean fever (FMF) is a common autoinflammatory disease. The primary treatment is colchicine; however, 5-10% of patients do not respond to colchicine and are considered colchicine resistant. Colchicine resistance and disease severity are highly associated, with each used to assess and define the other. In our review, we examined the most commonly used severity scores, damage indices, and definitions of colchicine resistance, revealing both shortcomings and advantages for each. We emphasize the necessity for a new severity score that integrates the definition of colchicine resistance.

The increased chromosomal DNA damage in patients with Familial Mediterranean Fever.

Familial Mediterranean Fever (FMF) is an inherited autoinflammatory disease. In this study, we aimed to assess chromosomal DNA damage and cell proliferation by using cytokinesis-block micronucleus cytome (CBMN-cyt) assay in the peripheral blood lymphocytes of untreated FMF patients carrying M694V and R202Q mutations, which are the most common MEFV gene mutations in Turkish society. The study included 20 untreated FMF patients with M694V and R202Q mutations and 20 healthy individuals of similar age and sex as the control group. Micronucleus (MN), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs) were scored in the obtained bi-nucleated (BN) cells. Additionally, the nuclear division index (NDI) was calculated using the scores of mononuclear, binuclear, and multinuclear cells. We found that MN and NPBs frequencies in FMF patients were significantly higher than in controls, and number of metaphases was significantly lower (respectively, p < 0.05, p < 0.01, and p < 0.01). However, there was no significant difference in NBUDs frequencies and NDI values between FMF patients and controls (p > 0.05). Our study is the first to evaluate FMF patients' lymphocytes using the CBMN-cyt assay, as no previous research has been found in this respect. Increased MN and NPB frequencies may be useful as biomarkers for chromosomal DNA damage, and may indicate a potential for elevated cancer risk in untreated FMF patients.

Solving a diagnostic dilemma in a patient with periodic fever-When the pieces of the puzzle finally fit.

The lack of pediatric subspecialists locally prior to 5 years ago, meant that some of our patients with rare, relapsing conditions were left behind. Familial Mediterranean fever can be diagnosed clinically and supported via genetic panel studies. Although neurological symptoms can be non-specific, this system symptomatology may lead patients and carers to seek medical attention. When neurological symptoms progress, seemingly refractory to first-line treatment, or suggestive of colchicine resistance, CNS demyelination should be considered by the neurologist. Abstract: Familial Mediterranean fever (FMF) is an inherited disorder with episodic fevers accompanied by pain in the abdomen, joints, or chest. It is a clinical entity that can be confirmed with a specific genetic mutation. Neurological symptoms have not been a focal point in clinical case descriptions. We aim to present the long road to diagnosing our patient, where the diagnostic clues centered around her neurological symptoms.

Potential association between M694V homozygous mutation in familial Mediterranean fever and eosinophilic intestinal inflammation: a pediatric case series.

Familial Mediterranean fever (FMF) is the most common hereditary systemic auto-inflammatory disease. Digestive complaint is a common feature during FMF attacks. Nevertheless, digestive complaint in attack-free period has scarcely been studied. This retrospective monocentric study aimed to describe the clinical, histological, and genetic features of pediatric patients with FMF who underwent endo-colonoscopy in this setting. Out of 115 patients with a diagnosis of FMF, 10 (8, 7%) underwent endoscopy or colonoscopy. All displayed homozygote MEFV M694V mutation and presented chronic abdominal pain, iron deficiency, and/or growth retardation. On the histological level, all patients displayed low-grade mucosal inflammation, characterized by a moderate eosinophilic infiltrate in the lamina propria sometimes associated with increased crypt apoptosis. The proportion of patients explored with endoscopy or colonoscopy was 0.4 patients per year in our center, compared with 5.7 patients per year nationwide. This study identified a specific intestinal phenotype that does not respond to the criteria of classical inflammatory bowel disease: pediatric FMF pediatric patients with homozygous MEFV M694V, abdominal pain, iron deficiency, and growth retardation should benefit from specialized gastroenterological advice.

How do gene mutation diversity and disease severity scoring affect physical capacity and quality of life in children/adolescents with Familial Mediterranean Fever?

OBJECTIVES: The aim of this study is to examine how gene mutation diversity and disease severity affect physical capacity and quality of life in children/adolescents with Familial Mediterranean Fever (FMF). METHODS: Eighty children/adolescents (42 female, 38 male) diagnosed with FMF according to Tell-Hashomer diagnostic criteria were included in this study. Disease severity score (PRAS), running speed and agility and strength subtests of Bruininks-Oseretsky Test of Motor Proficiency Second Edition Short Form (BOT-2 SF), Physical Activity Questionnaire, Pediatric Quality of Life Inventory 3.0 Arthritis Module (PedsQL) was used for evaluation. Participants were divided into 2 groups as M694V and other mutations according to MEFV gene mutation and were divided into 3 groups as mild, moderate and severe according to PRAS. RESULTS: When the data were compared between groups; in terms of gene mutation, a significant difference was observed in treatment subtest of PedsQL-parent form in favor of the M694V gene mutation group (p<0.05). In terms of PRAS, significant difference was seen in the pain, treatment subtests and total score of the PedsQL-child form, and in the pain, treatment, worry subtests and total score of the PedsQL-parent form in favor of the mild group (p<0.05). CONCLUSIONS: MEFV gene mutations in children and adolescents with FMF did not differ on physical capacity and quality of life. PRAS was not effective on physical parameters, but quality of life decreased as the severity score increased. Encouraging children/adolescents with FMF to participate in physical activity and to support them psychosocially can be important to improve their quality of life.

Characteristics of arthritis in patients with familial Mediterranean fever.

BACKGROUND: Many of the familial Mediterranean fever (FMF) patients present with arthritis during attacks, which may vary in its characteristics. AIMS: In this study, we aimed to describe and characterise arthritis in FMF patients. METHODS: We used our hospital's record system to retrospectively identify FMF patients with arthritis who presented to our clinic between 2005 and 2020. The prevalence, laboratory results of attack, remission periods, genetic mutations, demographic data, characteristics of attacks, characteristics of arthritis, comorbidities, treatments and treatment responses were recorded. RESULTS: Nine hundred fifty-four patients from a cohort of 2350 FMF patients had arthritis (40%). The male/female ratio was 0.49 in patients with arthritis. The frequency of at least one exon 10 mutation was high. The age of onset of symptoms was earlier for patients with arthritis. Monoarticular pattern was more frequent compared to oligo- and polyarticular patterns. Colchicine resistance was higher; the required colchicine dose for disease control and the frequency of use of biological agents were higher compared to general FMF population. CONCLUSION: Since M694V mutation is common and the colchicine dose required for disease control is high, we can conclude that the disease activity is high in FMF patients with arthritis. The frequency of sacroiliitis and spondyloarthropathy is significantly increased, especially in individuals with M694V mutation, suggesting that there may be a common pathway in their pathogenesis. FMF should be included in the differential diagnosis in patients presenting with arthritis in FMF endemic regions.

Reliability of a generative artificial intelligence tool for pediatric familial Mediterranean fever: insights from a multicentre expert survey.

BACKGROUND: Artificial intelligence (AI) has become a popular tool for clinical and research use in the medical field. The aim of this study was to evaluate the accuracy and reliability of a generative AI tool on pediatric familial Mediterranean fever (FMF). METHODS: Fifteen questions repeated thrice on pediatric FMF were prompted to the popular generative AI tool Microsoft Copilot with Chat-GPT 4.0. Nine pediatric rheumatology experts rated response accuracy with a blinded mechanism using a Likert-like scale with values from 1 to 5. RESULTS: Median values for overall responses at the initial assessment ranged from 2.00 to 5.00. During the second assessment, median values spanned from 2.00 to 4.00, while for the third assessment, they ranged from 3.00 to 4.00. Intra-rater variability showed poor to moderate agreement (intraclass correlation coefficient range: -0.151 to 0.534). A diminishing level of agreement among experts over time was documented, as highlighted by Krippendorff's alpha coefficient values, ranging from 0.136 (at the first response) to 0.132 (at the second response) to 0.089 (at the third response). Lastly, experts displayed varying levels of trust in AI pre- and post-survey. CONCLUSIONS: AI has promising implications in pediatric rheumatology, including early diagnosis and management optimization, but challenges persist due to uncertain information reliability and the lack of expert validation. Our survey revealed considerable inaccuracies and incompleteness in AI-generated responses regarding FMF, with poor intra- and extra-rater reliability. Human validation remains crucial in managing AI-generated medical information.

The Impact of Different MEFV Genotypes on Clinical Phenotype of Patients with Familial Mediterranean Fever: Special Emphasis on Joint Involvement.

Familial Mediterranean Fever (FMF) is the most common monogenic autoinflammatory disease worldwide. In this retrospective cohort study, we aimed to assess the effects of various MEFV genotypes on the clinical characteristics of the patients, with a special focus on the joint involvement. In total, 782 patients with FMF were categorized into 3 groups according to the MEFV mutation; Group 1: Patients homozygous for M694V; Group 2: Patients carrying other pathogenic MEFV variants in exon 10 in homozygous or compound heterozygous states; and Group 3: FMF patients with other variants or without mutations. Clinical and demographic findings were compared between groups. Among the 782 FMF patients, total frequency of arthritis was 237 (30.3%): 207 (26.4%) were acute monoarthritis and 67 (8.5%) were chronic arthritis. Both the frequency of arthritis (acute and/or chronic) (40.4% vs. 24.8% vs. 26.7%; p:0.001) and acute monoarthritis (35.4% vs. 20% vs. 23.7%; p:0.001) were significantly higher in Group 1 than in the other groups. FMF patients with chronic arthritis showed a distinct juvenile idiopathic arthritis (JIA) distribution pattern with a more frequent enthesitis-related arthritis (ERA) subtype (43.2%). HLA-B27 was positive in 24% of the ERA patients.Conclusion: Homozygous M694V mutation is associated with a more frequent and longer acute monoarthritis comparing to other MEFV genotypes. In addition, the risk of chronic arthritis seems not related to the MEFV mutations. However, FMF patients with chronic arthritis show a distinct ILAR JIA distribution pattern with a more frequent ERA and undifferentiated arthritis subtype. What is known: • Homozygous M694V mutation is associated with a more frequent and longer acute monoarthritis What is new: • FMF patients with chronic arthritis show a distinct ILAR JIA distribution pattern with a more frequent ERA subtype • ERA patients with negative HLA-B27 antigen should also be assessed for polyserositis episodes of FMF, especially in countries with high FMF carrier frequency.

E148Q variant: a familial Mediterranean fever-causing mutation or a sequence variant?

Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disease, linked to mutations in the MEFV gene. The p.E148Q variant, found on exon 2, has an uncertain role in FMF, with debates on whether it is a benign polymorphism or a pathogenic mutation. This study aimed to assess the clinical characteristics and severity of FMF in patients homozygous for the p.E148Q variant and to evaluate the impact of the p.V726A variant in these patients. This retrospective cohort study analyzed data from electronic medical records at Carmel Medical Center, Israel. Patients who underwent genetic testing for FMF from November 2004 to December 2019 and had p.E148Q/p.E148Q or p.E148Q/p.E148Q + p.V726A variants were included. Disease severity was assessed using the Tel Hashomer Key to Severity Score. Statistical analyses compared clinical characteristics and severity between genotype groups. The study included 61 FMF patients, with 24 (39%) having p.E148Q/p.E148Q and 37 (61%) having p.E148Q/p.E148Q + p.V726A variants. The majority (72%) were Druze. Most patients (65.5%) exhibited mild disease, while 31.1% had moderate disease, with no cases of severe disease. Colchicine treatment significantly reduced CRP levels in all patients. CONCLUSION: These findings suggest that the p.E148Q variant, whether alone or with p.V726A, generally results in mild to moderate FMF severity, supporting its pathogenic role in particular ethnicity. These results contribute to understanding the clinical significance of the p.E148Q variant and considering the patient's need for Colchicine treatment. WHAT IS KNOWN: • The role of the p.E148Q variant in FMF is debated, with questions about whether it is a benign polymorphism or a pathogenic mutation. • The prevalence of MEFV variants can vary significantly among different ethnic groups. WHAT IS NEW: • The p.E148Q variant has clinical significance in particular ethnicities, as supported by a significant reduction in CRP levels following colchicine treatment. • The p.E148Q variant, whether alone or with p.V726A, generally results in mild to moderate FMF severity.

[Challenges in diagnosing familial Mediterranean fever: exploring atypical clinical features. Clinical case].

This clinical case series presents descriptions of 3 patients with familial Mediterranean fever (FMF) who have atypical manifestations and abnormal inheritance mechanisms in terms of Gregor Mendel's laws. Although molecular genetic testing can help with disease diagnosis, it is not always conclusive. The primary need for genetic testing in atypical cases is to explain the mechanism of inflammation and to select the optimal therapy. These clinical observations demonstrate the changes in the spectrum of phenotypic manifestations of FMF in the context of the widespread introduction of molecular genetic methods.

Molecular analyses of MEFV gene mutation variants in Turkish population.

BACKGROUND: Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disease primarily affecting individuals of Turkish, Armenian, Arab, and non-Ashkenazi Jewish descent, caused by mutations in the MEFV gene. The aim of this study was to review the common genotype distributions of MEFV variants and mutations in the Turkish population and evaluate rare mutations. METHODS AND RESULTS: The study included 2984 patients who applied to Ankara University Ibni Sina Hospital Immunology Laboratory with clinical suspicion of FMF between 2004 and 2014. The data of patients from different regions of the country who were followed up in the immunology-rheumatology clinic with clinical suspicion and presumptive diagnosis of FMF were evaluated retrospectively. Patients were tested for all mutations in Exon 2 and Exon 10, including M694V, M680I, M694I, V726A, E148Q and R202Q. There were 2504 patients with FMF variant. According to genotyping, R202Q (n = 1567, 39.2%) was the most common mutation. The most common co-variant was the R202Q/M694V genotype (n = 507, 16.98%). Allele frequencies for MEFV mutations were as follows: R202Q (n = 1567, 39.2%), M694V (n = 1004, 25.1%), E148Q (n = 463, 11.5%), M680I (n = 354, 8.8%), V726A (n = 319, 7.9%), A744S (n = 51, 1.2%), R761H (N = 41, 1.0%), P706P (N = 25, 0.6%), E167D (N = 23, 0.5%), M694I (N = 23, 0.5%), and K695R (N = 20, 0.5%). CONCLUSION: This research revealed the prevalence of both common and rare MEFV gene mutations in Turkish FMF patients in various age groups. R202Q was the most prevalent mutation.