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. 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. • 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. • 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.

Orouk Awaad E ，Khoury L ，van Straalen JW ，Miller-Barmak A ，Gazitt T ，Haddad-Haloun J ，Brik R ，Hamad Saied M ... -  《-》

Familial Mediterranean fever patients homozygous for E148Q variant may have milder disease.

Familial Mediterranean fever (FMF) results from MEFV gene mutations. E148Q is a variant of unknown significance in MEFV. We aimed to define characteristics of FMF patients homozygous for E148Q, check for other MEFV variants in a subgroup, and compare the characteristics with FMF patients carrying other mutations. Thirty FMF patients homozygous for E148Q were reviewed. MEFV variant analysis was performed with strip assay. All MEFV exons were screened by direct DNA sequencing in 14 randomly selected E148Q/E148Q patients. E148Q was also checked in 100 healthy adolescents. We compared the characteristics of FMF patients between three groups: E148Q/E148Q (n = 30), M694V/E148Q (n = 19) and exon 10/exon 10 MEFV mutations (n = 48). Among 30 FMF patients (E148Q/E148Q), the median age at disease onset and diagnosis were 60 (12-168) and 94 (41-196) months, respectively. Fifteen (50%) patients had mild, 14 (46.7%) moderate and one (3.3%) had severe disease. Twenty-two (73.3%) patients had complete, seven (23.3%) had incomplete response to colchicine, while only one was unresponsive. The detected MEFV variants in 14 E148Q/E148Q FMF patients were as follows: R314R (n = 9; 64.3%), E474E (n = 13; 92.9%), Q476Q (n = 13; 92.9%), D510D (n = 13; 92.9%), and P588P (n = 8; 57.1%). The E148Q allele frequency was 6.5% in healthy adolescents. When compared to FMF patients with other MEFV mutations, disease onset was later, disease was less severe and the ratio of patients responding completely to colchicine was higher in E148Q/E148Q patients. Patients homozygous for E148Q and negative for other pathogenic MEFV variants may display FMF phenotype and may experience moderate/severe disease activity, although the disease may be milder when compared to FMF patients with other mutations.

Topaloglu R ，Batu ED ，Yıldız Ç ，Korkmaz E ，Özen S ，Beşbaş N ，Özaltın F ... -  《-》

Clinical features and disease severity of Turkish FMF children carrying E148Q mutation.

Familial Mediterranean fever (FMF) is the most common hereditary monogenic autoinflammatory disease caused by mutations in the MEFV gene. It is controversial whether E148Q alteration is an insignificant variant or a disease-causing mutation. The aim of this study was to evaluate the clinical features and disease severity of FMF patients carrying E148Q mutation. Files of FMF patients were retrospectively evaluated. Patients with at least one E148Q mutation were included to the study. The clinical characteristics and disease severity of the patients who were carrying only E148Q mutation were compared with the patients who were compound heterozygous for E148Q and homozygous for M694V mutation. The study group comprised 33 patients who were homozygous or heterozygous for E148Q; 34 with compound heterozygous E148Q mutations and 86 patients who had homozygous M694V mutation. Patients who had only E148Q mutation were found to have the oldest mean age of disease onset and lowest mean disease severity score. Attack frequency and colchicine doses were lower in patients with only E148Q mutation as compared with the other two groups. The frequency of clinical findings such as fever, abdominal pain, arthralgia, and arthritis among the three groups was similar. Familial Mediterranean fever patients with only E148Q mutation are presenting with late-onset and milder disease course despite having similar clinical findings as compared with patients who had other mutations. Finally, we imply that E148Q is a mutation and colchicine treatment should be given.

Aydın F ，Çakar N ，Özçakar ZB ，Uncu N ，Başaran Ö ，Özdel S ，Çelikel E ，Elhan AH ，Yalçınkaya F ... -  《-》

Clinical and diagnostic value of genetic testing in 216 Israeli children with Familial Mediterranean fever.

Padeh S ，Shinar Y ，Pras E ，Zemer D ，Langevitz P ，Pras M ，Livneh A ... -  《JOURNAL OF RHEUMATOLOGY》

Genotype-phenotype associations in familial Mediterranean fever: a study of 500 Egyptian pediatric patients.

Familial Mediterranean fever (FMF) is the most prevalent monogenic autoinflammatory disease, caused by recessively inherited MEFV gene mutations. The most frequent MEFV mutations differ in penetrance and disease severity. We investigated the genotype-phenotype associations of the three most frequent MEFV gene mutations (M680I, M694V, and V726A) in Egyptian FMF children, regarding clinical features, severity, and colchicine response. We conducted a retrospective analysis of the medical registries of 500 FMF pediatric patients from Metropolitan Cairo between 2010 and 2015. The diagnosis was based on the Tel-Hashomer clinical diagnostic criteria. Clinical data and baseline investigations were collected. Mutation analysis was performed by the amplification-refractory mutation system (ARMS)-PCR method. Males represented 54% and ages ranged from 2 to 18 years. The most frequent symptoms were abdominal pain, fever, and arthralgia. Clinical features mostly associated with M694V mutation either homozygous or heterozygous whether simple, double, or triple. Of the patients, 94.6% completely responded to colchicine. Among patients benefiting from colchicine, 42.5% had M694V/V726A, 21.6% had M694V/V726A/M680I, and 21.1% had M694V genotype. Simple heterozygous M694V or V726A mutations conveyed a moderate phenotype in 57.1% and 50% of cases, respectively. Homozygous M694V mutation showed moderate and severe phenotypes in 21.7% and 65.2% of cases, respectively. Compound M694V/V726A mutation associated with moderate or severe disease in 48.3% and 33.8% of cases, respectively. This study encompasses the largest group of Egyptian pediatric FMF up to date to explore their genotype-phenotype associations. Our results support the notion that the genotype influences the phenotype as regards clinical manifestations, disease severity, and colchicine response. • This study encompasses the largest group of Egyptian pediatric patients affected by FMF up to date to explore their genotype-phenotype associations. • Our results support the notion that the genotype influences the phenotype as regards the clinical manifestations, the disease severity, and the response to colchicine treatment.

Beshlawy AE ，Zekri AER ，Ramadan MS ，Selim YMM ，Abdel-Salam A ，Hegazy MT ，Ragab L ，Gaggiano C ，Cantarini L ，Ragab G ... -  《-》