R92Q Mutation Research Articles

Allele-specific silencing by RNAi of R92Q and R173W mutations in cardiac troponin T.

Autosomal dominant mutations in sarcomere proteins such as the cardiac troponin T (TNNT2) are the main genetic causes of human hypertrophic cardiomyopathy and dilated cardiomyopathy. Allele-specific silencing by RNA interference (ASP-RNAi) holds promise as a therapeutic strategy for downregulating a single mutant allele with minimal suppression of the corresponding wild-type allele. Here, we propose ASP-RNAi as a possible strategy to specifically knockdown mutant alleles coding for R92Q and R173W mutant TNNT2 proteins, identified in hypertrophic and dilated cardiomyopathy, respectively. Different siRNAs were designed and validated by luciferase reporter assay and following analysis in HEK293T cells expressing either the wild-type or mutant TNNT2 alleles. This study is the first exploration of ASP-RNAi on TNNT2-R173W and TNNT2-R92Q mutations in vitro and gives a base for further application of allele silencing as a therapeutic treatment for TNNT2-mutation-associated cardiomyopathies.

Anakinra and canakinumab for patients with R92Q-associated autoinflammatory syndrome: a multicenter observational study from the AIDA Network.

Background:This study aims at describing the therapeutic outcome of patients carrying the R92Q variant in the TNFRSF1A gene treated with anakinra (ANA) or canakinumab (CAN) and identifying any factors predictive of complete response to IL-1 inhibition.Methods:Clinical data of patients treated with ANA or CAN for recurrent inflammatory attacks due to the presence of the R92Q variant were retrospectively collected and analysed.Results:Data about 20 treatment courses with IL-1 inhibitors (16 with ANA and 4 with CAN) from 19 patients were collected. Mean age at disease onset was 20.2 ± 14.8 years. In 5 cases (26%) the R92Q variant was found in a family member affected by recurrent fever. The therapeutic response was complete in 13(68%) and partial in 2 patients (11%); treatment failure was observed in 4 cases (21%). Median AIDAI decreased from 10 (interquartile range [IQR] = 28) to 0 (IQR = 1) at the 12-month follow-up visit (p < 0.001). Mean ESR and median CRP dropped respectively from 40.8 ± 24.8 to 9.1 ± 4.5 mm/h (p < 0.001) and from 3.0 (IQR = 1.9) to 0.3 (IQR = 0.3) mg/dl (p < 0.001) after 12 months of treatment. A steroid-sparing effect was observed from the third month of treatment (p < 0.01). Thirteen patients (65%) were still on treatment at the last follow-up visit (median duration of treatment 17 (IQR = 38) months). The presence of R92Q mutation in a symptomatic relative (p = 0.022), the relapsing remitting disease course (p < 0.001) and the presence of migratory erythematous skin rashes during fever attacks (p = 0.005) were associated with complete efficacy of IL-1 inhibitors.Conclusions:R92Q patients showed a favourable response to ANA and CAN, particularly when the mutation segregated in a family member and when a relapsing-remitting disease course or TNF-α receptor-associated periodic syndrome (TRAPS) typical skin rash were observed. In the subgroup of patients not taking advantage of IL-1 blockage different molecular mechanisms underlying the autoinflammatory picture are likely to exist.

Low-penetrance R92Q (p.Arg121Gln) mutation in the &lt;i&gt;TNFRSF1A&lt;/i&gt; gene: the significance and variants of phenotypes. Successful experience with the interleukin-1 inhibitor canakinumab in a female patient, who is a carrier of R92Q mutation with a severe TRAPS phenotype

The paper is devoted to the assessment of the R92Q (p.Arg121Gln) mutation/polymorphism in the TNFRSF1A gene associated with the monogenic autoinflammatory disease – Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS). It gives data on the frequency of this gene in the general population, which is 1.3% and significantly exceeds the incidence of TRAPS. The authors describe the variants of phenotypes associated with its mutation from asymptomatic carriage to the development of a severe systemic autoinflammatory state with persistent febrile fever and a significant increase in the level of acute-phase inflammatory markers that do not respond to standard antirheumatic therapy. They present a clinical case of the high efficiency of the anti-interleukin 1β monoclonal antibody canakinumab in a female patient with a severe TRAPS phenotype, who had the R92Q mutation and hormonal dependence. Canakinumab therapy led to complete relief from all manifestations of the disease and to discontinuation of glucocorticoids. The authors conclude that the decision to prescribe therapy with biological agents should be made on the basis of the clinical severity of the disease rather than a variant of the mutation that caused it.

Clinical dose effect and functional consequences of R92Q in two families presenting with a TRAPS/PFAPA-like phenotype.

BackgroundTNF receptor‐associated syndrome (TRAPS) is a dominantly inherited autoinflammatory condition caused by mutations in the TNFRSF1A gene. The mechanism underlying the variable expressivity of the common variant R92Q (rs4149584; c.362G>A; p.Arg121Gln) is unclear and is of critical importance for patient care and genetic counseling. This study evaluated the impact of the number of R92Q mutations in two unique unrelated families.MethodsTwo patients with undefined but clear autoinflammatory symptoms were referred for genetic diagnosis. Blood samples were collected from the available family members to screen autoinflammatory genes and assess key steps of the TNFR1‐mediated signaling pathway using flow cytometry and ex vivo culture.ResultsR92Q homozygosity was demonstrated for the two probands. In family 1, the segregation analysis revealed TRAPS‐like symptoms in all carriers, with a more severe presentation in the proband, whereas in family 2, the heterozygous parents were totally asymptomatic, suggesting recessive transmission. Functional studies revealed a nonclassical pathogenesis of TRAPS in the two probands and suggested a compensatory mechanism without clear dose effect.ConclusionWe observed for the first time a possible clinical dose effect of R92Q. This work highlights the importance of familial studies to reconcile the contradictory reports published on the pathogenicity of this variant.

The significance and occurrence of TNF receptor polymorphisms in the Saudi population.

Background and objective: On the basis that the inflammatory effects of TNF (tumour necrosis factor) are predominantly mediated through interaction with the TNF receptor-1 (TNFRSF1A), the current study was designed to establish the prevalence of the mutations, R92Q and P46L TNFRSF1A polymorphisms both in the general healthy Saudi population, and in Saudi patients carrying inflammatory diseases such as atherosclerosis or rheumatoid arthritis. We felt it important to report the frequency of the mutations, R92Q and P46L TNFRSF1A polymorphisms in healthy Saudi individuals, and those with inflammatory conditions, as well as to describe the pattern of immunological factors in individuals expressing R92Q or P46L TNFRSF1A. Patients and methods: We collected in PAX gene blood RNA tubes (for RT-PCR and sequencing) 500 blood samples from normal healthy individuals from the West and Center of Saudi Arabia, as well as 100 from patients with atherosclerosis, and 100 patients diagnosed with rheumatoid arthritis. All were screened for the levels of soluble TNF, C-reactive protein (CRP), interleukin6 (IL-6) and sTNFR1. In addition, they were screened for R92Q and P46L TNFRSF1A by RT-PCR. Moreover, phenotype and expression of peripheral blood mononuclear cells (PBMCs) was performed by flow cytometry (FACS). Results: Across 500 normal individuals, 8 (1.6%) expressed both R92Q and P46L mutations. By contrast, of the 100 patients in our study with atherosclerosis, 34% expressed both the R92Q and P46L mutations, whilst 42% of patients with rheumatoid arthritis expressed both mutations R92Q and P46L. No significant differences were observed between cell markers of normal individuals (CD3, 4, 8, 16, 56, 19, 25, ICAM-1, VLA-4 & l-selectin) and patients with atherosclerosis. There were significantly high values of cell markers in patients with rheumatoid arthritis compared with normal individuals both in terms of percentage and absolute counts (p < 0.05). Soluble IL-6 and sTNFR1 showed significant decreases in atherosclerosis and rheumatoid arthritis when compared with controls (p < 0.05). In addition, CRP and sTNF showed significant increases in the atherosclerosis and rheumatoid arthritis groups when compared to controls (p < 0.05). Conclusion: Our findings reasonably anticipate the presence of TRAPS disease (low penetrance mutations) amongst the Saudi population although further studies are needed to confirm these results.

Molecular dynamics and intracellular signaling of the TNF-R1 with the R92Q mutation

The tumor necrosis factor receptor superfamily, member 1A (TNFRSF1A) gene encodes the TNF-R1, one of the main TNF receptors that mediates its inflammatory actions. In a recent study, serum levels of the soluble TNF-R1 and mRNA levels of the full-length receptor were found to be significantly increased in multiple sclerosis (MS) patients carrying the R92Q mutation. Interestingly, R92Q-mutated patients were younger at disease onset and progressed slower as compared to non-carriers. Building on these previous findings, here we aimed to investigate by means of both in silico and in vitro approaches the mechanisms relating the R92Q substitution with functional changes of the receptor and their potential effects modulating MS disease course. Models of the extracellular domains of the human TNF-R1 and human TNF-R1 carrying the R92Q mutation, alone or bound to TNF, were constructed and submitted to molecular dynamics. TRAF2 and CASP3 mRNA expression levels were determined by real-time PCR in peripheral blood mononuclear cells (PBMC) from 61 MS patients, 9 R92Q carriers and 52 non-carriers (CT and CC genotypes for SNP rs4149584, respectively). Molecular dynamic studies revealed that the R92Q mutation increased the contact area between receptor and TNF (1070 and 1388Å2 for native and mutated receptor) and decreased the distance between them (28.7 to 27.9Å), while Van der Waals and electrostatic interaction energies were increased. In PBMC from MS patients carrying the R92Q mutation, CASP3 mRNA expression levels were significantly increased compared to non-carriers, whereas a trend was observed for TRAF2. These data suggest that the R92Q mutation gives rise to a stronger interaction between the receptor and its ligand, which results in the potentiation of TNF-mediated pathways. Although further studies are needed, these functional changes may be related with the modulation in disease course reported in MS patients carrying the R92Q mutation.

NLRP3 Q703K and TNFRSF1A R92Q mutations in a patient with auto inflammatory disease

Results At the age of 2 the patient was hospitalized for recurrent fever (39 41°C) during several months. Recurrent infections were suspected, although presence of bacteria or virus could not be confirmed. Clinical examination revealed multiple lymph nodes and enlarged tonsils. At the age of 4, the boy was hospitalized because of chronic abdominal pain. At the age of 5, neurological development became abnormal and psychomotor development deficiency was diagnosed. By the age of 8 symptoms included ataxia, abdominal pain, headache, fatigue, arthralgia and myalgia. Neurological symptoms were rapidly progressive. Within few months the patient was unable to walk. In addition, pyoderma grangrenosum-like skin lesions appeared. After several months, slow improvement was noticed. He was 15 years old when he presented with an episode of periorbital edema and fever. At the age of 18 recurrent fever, headache and abdominal pain persisted. The laboratory tests showed elevated CRP and IgD, but no signs of infection. Periodic fever syndrome was suspected and genetic analysis confirmed the presence of a Q703K and R92Q Mutation.

The novel S59P mutation in the TNFRSF1A gene identified in an adult onset TNF receptor associated periodic syndrome (TRAPS) constitutively activates NF-κB pathway

IntroductionMutations in the TNFRSF1A gene, encoding tumor necrosis factor receptor 1 (TNF-R1), are associated with the autosomal dominant autoinflammatory disorder, called TNF receptor associated periodic syndrome (TRAPS). TRAPS is clinically characterized by recurrent episodes of long-lasting fever and systemic inflammation. A novel mutation (c.262 T > C; S59P) in the TNFRSF1A gene at residue 88 of the mature protein was recently identified in our laboratory in an adult TRAPS patient. The aim of this study was to functionally characterize this novel TNFRSF1A mutation evaluating its effects on the TNF-R1-associated signaling pathways, firstly NF-κB, under particular conditions and comparing the results with suitable control mutations.MethodsHEK-293 cell line was transfected with pCMV6-AC construct expressing wild-type (WT) or c.262 T > C (S59P), c.362G > A (R92Q), c.236C > T (T50M) TNFRSF1A mutants. Peripheral blood mononuclear cells (PBMCs) were instead isolated from two TRAPS patients carrying S59P and R92Q mutations and from five healthy subjects. Both transfected HEK-293 and PBMCs were stimulated with tumor necrosis factor (TNF) or interleukin 1β (IL-1β) to evaluate the expression of TNF-R1, the activation of TNF-R1-associated downstream pathways and the pro-inflammatory cytokines by means of immunofluorescent assay, array-based technique, immunoblotting and immunometric assay, respectively.ResultsTNF induced cytoplasmic accumulation of TNF-R1 in all mutant cells. Furthermore, all mutants presented a particular set of active TNF-R1 downstream pathways. S59P constitutively activated IL-1β, MAPK and SRC/JAK/STAT3 pathways and inhibited apoptosis. Also, NF-κB pathway involvement was demonstrated in vitro by the enhancement of p-IκB-α and p65 nuclear subunit of NF-κB expression in all mutants in the presence of TNF or IL-1β stimulation. These in vitro results correlated with patients’ data from PBMCs. Concerning the pro-inflammatory cytokines secretion, mainly IL-1β induced a significant and persistent enhancement of IL-6 and IL-8 in PBMCs carrying the S59P mutation.ConclusionsThe novel S59P mutation leads to defective cellular trafficking and to constitutive activation of TNF-R1. This mutation also determines constitutive activation of the IL-1R pathway, inhibition of apoptosis and enhanced and persistent NF-κB activation and cytokine secretion in response to IL-1β stimulation.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-015-0604-7) contains supplementary material, which is available to authorized users.

Life-Long Treatment with Late Sodium Current Blocker Reduces Myocardial Dysfunction and Remodeling in a Mouse Model of Hypertrophic Cardiomyopathy

No drugs are capable to prevent phenotype development and adverse cardiac remodeling in hypertrophic cardiomyopathy (HCM). Ranolazine, a late Na+ current blocker, reduced arrhythmogenicity and improved relaxation in cardiomyocytes and trabeculae from HCM patients (Coppini et al., Circulation 2013). Employing a transgenic mouse model carrying the HCM-associated R92Q mutation in the TNNT2 gene, we previously showed that acute in vitro treatment with ranolazine is capable to reverse some electromechanical alterations, including the prolonged kinetics of Ca2+ transients, the higher diastolic [Ca2+] and the increased frequency of arrhythmogenic spontaneous activity (Pioner et al., Biophys J 2014, 106, 644a). Here we employed the same mouse model to assess whether long-term oral treatment with ranolazine since birth is capable to prevent the HCM phenotype and the associated myocardial remodeling. We compared the behavior of WT, R92Q-untreated and R92Q-treated 1 year old mice. Echocardiographic measurements showed that the R92Q-treated in vivo hearts lacked the left ventricular hypertrophy, hypercontractility and diastolic dysfunction found in the R92Q-untreated mice. Gadolinium-contrast magnetic resonance showed that the intramyocardial fibrosis of the R92Q-untreated hearts was largely reduced in the treated mice.Both amelioration of cardiomyocyte function and reduction of extracellular fibrosis may contribute to the positive effect of the long-term treatment with ranolazine that could represent a candidate for preventive treatment of phenotype-negative mutation carriers. Mechanical experiments in intact left and right ventricular trabeculae confirmed the alterations we had previously reported in R92Q-untreated mice compared to WT and showed that those alterations were mostly reversed in the R92Q-treated mice. In the R92Q-treated preparations the inotropic response to isoproterenol was preserved and the occurrence of spontaneous activity was markedly reduced compared to the untreated trabeculae and was comparable to that of WT trabeculae.

TNFRSF1A gen and R92Q and P46L variants. Association with other inflammatory diseases

Tumour Necrosis Factor (TNF) Receptor-Associated Periodic Syndrome (TRAPS) is an autoinflammatory disease with an autosomal dominant inheritance pattern. Structural mutations in the TNFRSF1A gen tend to have a penetrance higher than 90%, except for p.P46L and p.R92Q variants. The intensity of clinical manifestations in patients with these variants has been shown to decrease or even to disappear in the long term follow-up. It has been found a high prevalence of the R92Q mutation in patients with inflammatory diseases known to have a relevant TNF-alfa involvement.

PReS-FINAL-2235: Overlap of homozygous TNFRSF1A R92Q mutation with MEVF E148Q mutation versus homozygous TNFRSF1A R92Q mutation: difference in clinical profile in two sisters from Oman

Tumor necrosis factor receptor associated periodic syndrome (TRAPS) is a multifaceted auto inflammatory syndrome which was initially described in persons of Irish-Scottish ancestry and in ethnic groups of northern European descent. To date, more than 70 mutations have been described. Since then, it has been described in other ethnicities. There have been few reports of from Asia, 11 cases have been described from Japan, and only one case of TRAPS has been described in an Arab child from Israel (1-8).There are no cases of TRAPS that have been described from Gulf Arab states.

P02-014 - Consequences of Arginine 92 mutations in TNFR1

TNFRSF1A is involved in a Mendelian autosomal dominant autoinflammatory disorder called TNFR-associated periodic syndrome (TRAPS). Most TNFRSF1A mutations are missense changes and, apart from those affecting conserved cysteines, their deleterious effect remains often questionable. This is especially true for the frequent R92Q mutation, which might not be responsible for TRAPS per se but represents a susceptibility factor to multifactorial inflammatory disorders.

Involvement of the Same TNFR1 Residue in Mendelian and Multifactorial Inflammatory Disorders

Objectives TNFRSF1A is involved in an autosomal dominant autoinflammatory disorder called TNFR-associated periodic syndrome (TRAPS). Most TNFRSF1A mutations are missense changes and, apart from those affecting conserved cysteines, their deleterious effect remains often questionable. This is especially true for the frequent R92Q mutation, which might not be responsible for TRAPS per se but represents a susceptibility factor to multifactorial inflammatory disorders. This study investigates TRAPS pathophysiology in a family exceptional by its size (13 members) and compares the consequences of several mutations affecting arginine 92.Methods TNFRSF1A screening was performed by PCR-sequencing. Comparison of the 3-dimensional structure and electrostatic properties of wild-type and mutated TNFR1 proteins was performed by in silico homology modeling. TNFR1 expression was assessed by FACS analysis, western blotting and ELISA in lysates and supernatants of HEK293T cells transiently expressing wild-type and mutated TNFR1.ResultsA TNFRSF1A heterozygous missense mutation, R92W (c.361C>T), was shown to perfectly segregate with typical TRAPS manifestations within the family investigated (p<5.10−4). It was associated with very high disease penetrance (0.9). Prediction of its impact on the protein structure revealed local conformational changes and alterations of the receptor electrostatic properties. R92W also impairs the TNFR1 expression at the cell surface and the levels of soluble receptor. Similar results were obtained with R92P, another mutation previously identified in a very small familial form with incomplete penetrance and variable expressivity. In contrast, TNFR1-R92Q behaves like the wild-type receptor.ConclusionsThese data demonstrate the pathogenicity of a mutation affecting arginine 92, a residue whose involvement in inflammatory disorders is deeply debated. Combined with previous reports on arginine 92 mutations, this study discloses an unusual situation in which different amino acid substitutions at the same position in the protein are associated with a clinical spectrum bridging Mendelian to multifactorial conditions.

TNFRSF1A polymorphisms rs1800693 and rs4149584 in patients with multiple sclerosis

To investigate the roles of 2 polymorphisms of the tumor necrosis factor (TNF) receptor superfamily member 1A (TNFRSF1A) gene, rs1800693 (a common variant) and rs4149584 (a coding polymorphism that results in an amino acid substitution-R92Q), as genetic modifiers of multiple sclerosis (MS), and to evaluate their potential functional implications in the disease. The effects of rs1800693 and rs4149584 on 2 measures of disease severity, age at disease onset and Multiple Sclerosis Severity Score, were analyzed in 2,032 patients with MS. In a subgroup of patients, serum levels of the soluble form of TNF-R1 (sTNF-R1) were measured by ELISA; mRNA expression levels of the full-length TNF-R1 and Δ6-TNF-R1 isoform were investigated in peripheral blood mononuclear cells (PBMC) by real-time PCR; cell surface expression of the TNF-R1 was determined in T cells by flow cytometry. For rs4149584, R92Q carriers were younger at disease onset and progressed slower compared to noncarriers. However, no association with disease severity was observed for rs1800693. Serum levels of sTNF-R1 and mRNA expression levels of the full-length receptor were significantly increased in patients with MS carrying the R92Q mutation (p = 0.003 and p = 0.011, respectively), but similarly distributed among rs1800693 genotypes; cell surface TNF-R1 expression in T cells did not differ between rs4149584 and rs1800693 genotypes. The truncated soluble Δ6-TNF-R1 isoform was identified in PBMC from patients carrying the risk allele for rs1800693. These findings suggest that both rs1800693 and rs4149584 TNFRSF1A polymorphisms have functional consequences in the TNF-R1.

Effects of R92 mutations in mouse cardiac troponin T are influenced by changes in myosin heavy chain isoform

One limitation in understanding how different familial hypertrophic cardiomyopathy (FHC)-related mutations lead to divergent cardiac phenotypes is that such mutations are often studied in transgenic (TG) mouse hearts which contain a fast cycling myosin heavy chain isoform (α-MHC). However, the human heart contains a slow cycling MHC isoform (β-MHC). Given the physiological significance of MHC-troponin interplay effects on cardiac contractile function, we hypothesized that cardiac troponin T (cTnT) mutation-mediated effects on contractile function depend on the type of MHC isoform present in the sarcomere. We tested our hypothesis using two variants of cTnT containing mutations at FHC hotspot R92 (R92L or R92Q), expressed against either an α-MHC or β-MHC background in TG mouse hearts. One finding from our study was that R92L attenuated the length-dependent increase in tension and abolished the length-dependent increase in myofilament Ca2+ sensitivity only when β-MHC was present. In addition, α- and β-MHC isoforms differentially affected how R92 mutations altered crossbridge (XB) recruitment dynamics. For example, the rate of XB recruitment was faster in R92L or R92Q fibers when β-MHC was present, but was unaffected when α-MHC was present. The R92Q mutation sped XB detachment in the presence of β-MHC, but not in the presence of α-MHC. R92Q affected the XB strain-dependent influence on XB recruitment dynamics, an effect not observed for R92L. Our findings have major implications for understanding not only the divergent effects of R92 mutations on cardiac phenotype, but also the distinct effects of MHC isoforms in determining the outcome of mutations in cTnT.

Role of tumour necrosis factor (TNF)-α and TNFRSF1A R92Q mutation in the pathogenesis of TNF receptor-associated periodic syndrome and multiple sclerosis.

It has long been known that tumour necrosis factor (TNF)/TNFRSF1A signalling is involved in the pathophysiology of multiple sclerosis (MS). Different genetic and clinical findings over the last few years have generated renewed interest in this relationship. This paper provides an update on these recent findings. Genome-wide association studies have identified the R92Q mutation in the TNFRSF1A gene as a genetic risk factor for MS (odds ratio 1·6). This allele, which is also common in the general population and in other inflammatory conditions, therefore only implies a modest risk for MS and provides yet another piece of the puzzle that defines the multiple genetic risk factors for this disease. TNFRSF1A mutations have been associated with an autoinflammatory disease known as TNF receptor-associated periodic syndrome (TRAPS). Clinical observations have identified a group of MS patients carrying the R92Q mutation who have additional TRAPS symptoms. Hypothetically, the co-existence of MS and TRAPS or a co-morbidity relationship between the two could be mediated by this mutation. The TNFRSF1A R92Q mutation behaves as a genetic risk factor for MS and other inflammatory diseases, including TRAPS. Nevertheless, this mutation does not appear to be a severity marker of the disease, neither modifying the clinical progression of MS nor its therapeutic response. An alteration in TNF/TNFRS1A signalling may increase proinflammatory signals; the final clinical phenotype may possibly be determined by other genetic or environmental modifying factors that have not yet been identified.

Tumor Necrosis Factor Receptor-Associated Periodic Fever Syndrome in a 58-Year-Old Man

Tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS) is a rare systemic autoinflammatory disorder characterized by recurrent episodes of fever and localized inflammation of different organs. The disease is dominantly inherited, with an onset usually in early childhood. We describe a case of a 58-year-old patient with TRAPS caused by the low-penetrance R92Q mutation in TNFRSF1A gene. The patient responded well to anti-tumor necrosis factor α therapy. Although periodic fever syndromes, including TRAPS, mainly begin in early childhood, it is important to consider periodic fever syndrome also in patient presenting at an age older than the average reported case for TRAPS.

TNFSFR1A R92Q mutation, autoinflammatory symptoms and multiple sclerosis in a cohort from Argentina

Systemic autoinflammatory diseases are genetic disorders characterized by seemingly unprovoked inflammation, without major involvement of the adaptive immune system. Among them it is recognized the TNF receptor associated periodic syndrome (TRAPS) caused by mutations in the TNFRSF1A gene and characterized by symptoms such as recurrent high fevers, rash, abdominal pain, arthralgia and myalgia. Recent studies have recognized the potential role of TNFRSF1A mutations in Multiple Sclerosis (MS). Our aim was to investigate the role of TNFRSF1A R92Q gene mutation in a cohort of 90 Argentinean MS patients, where we determined the frequency of the TNFRSF1A R92Q mutation. We also compared autoinflammatory symptoms, MS clinical characteristics and treatment response and tolerability in R92Q carriers and non-carriers. Also, we used a case-control study design to obtain the genotypes of 78 healthy controls and assess the role of this mutation as a risk factor for MS. We found that five patients (5.5%) carried the R92Q mutation, four reported autoinflammatory symptoms previous to MS onset. We found no differences in MS clinical features, treatment response and tolerability between carriers and non-carriers. R92Q mutation was more frequent in MS patients as compared to controls. This increases the risk to develop MS in about 4.5 times. The TNFRSF1A R92Q mutation is a common finding in Argentinean MS patients. This genetic variant might be a risk factor for MS.

Long‐term clinical profile of children with the low‐penetrance R92Q mutation of the TNFRSF1A gene

ObjectiveTo analyze the long-term impact of the R92Q mutation of TNFRSF1A in children with periodic fever, in comparison with children with tumor necrosis factor receptor–associated periodic syndrome (TRAPS) with TNFRSF1A structural mutations and children with periodic fever of unknown origin fulfilling the criteria for periodic fever, aphthosis, pharyngitis, and adenitis syndrome (PFAPA).MethodsThe extracellular region of TNFRSF1A was analyzed in 720 consecutive children with periodic fever, using denaturing high-performance liquid chromatography and DNA sequencing. Followup data on 11 pediatric patients with TNFRSF1A structural mutations (cysteine or T50M), 23 pediatric patients with an R92Q substitution, and 64 pediatric patients with PFAPA were collected during routine clinic visits. The 50-item Child Health Questionnaire was used to assess health-related quality of life (HRQOL).ResultsThe frequency of typical TRAPS-related clinical manifestations was significantly lower and the impact of the disease on HRQOL was significantly reduced in patients with the R92Q mutation compared with TRAPS patients carrying structural mutations of TNFRSF1A. Followup data on 11 TRAPS patients with TNFRSF1A structural mutations (mean followup 7.9 years), 16 patients with theR92Q substitution (mean followup 7.3 years), and 64 patients with PFAPA (mean followup 5.2 years) were available. Patients with R92Q mutations and patients with PFAPA displayed a higher rate of self-resolution or amelioration of the fever episodes than did TRAPS patients with structural mutations.ConclusionAlthough some cases may progress to a more chronic disease course, the majority of children with an R92Q mutation of the TNFRSFA1 gene show a milder disease course than that in children with TNFRSFA1 structural mutations and have a high rate of spontaneous resolution and amelioration of the recurrent fever episodes.

Role of the R92Q TNFRSF1A mutation in patients with familial Mediterranean Fever

To define the frequency of the R92Q tumor necrosis factor receptor-associated periodic syndrome (TRAPS) mutation in patients with familial Mediterranean fever (FMF) and to study the role of this mutation in FMF. Ninety-two FMF patients and 250 controls were genotyped for the R92Q mutation. The frequency of R92Q was assessed among 5 groups of FMF patients. R92Q was found in 6% of the controls, with an especially high carrier rate among Moroccan Jews (8%). R92Q was found in 3 (3.2%) of the 92 FMF patients, 1 homozygous for the MEFV M694V mutation and 2 heterozygous for M694V. All 3 patients showed partial response to colchicine. R92Q was not found in patients unresponsive to colchicine, nor was it found in patients with amyloidosis or in patients with FMF-like disease without MEFV mutations. The frequency of the R92Q mutation in FMF patients is comparable with that of controls. Despite the fact that TRAPS and FMF share common biochemical pathways, we found no evidence for an interaction between these two genes.