Missense mutations in the MEFV gene are associated with fibromyalgia syndrome and correlate with elevated IL-1beta plasma levels

A Comprehensive Review of the Genetic and Epigenetic Contributions to the Development of Fibromyalgia

This narrative review summarizes the current knowledge of the genetic and epigenetic contributions to the development of fibromyalgia (FM). Although there is no single gene that results in the development of FM, this study reveals that certain polymorphisms in genes involved in the catecholaminergic pathway, the serotonergic pathway, pain processing, oxidative stress, and inflammation may influence susceptibility to FM and the severity of its symptoms. Furthermore, epigenetic changes at the DNA level may lead to the development of FM. Likewise, microRNAs may impact the expression of certain proteins that lead to the worsening of FM-associated symptoms.

Clinical and functional impact of central sensitization on patients with familial Mediterranean fever: a cross-sectional study

This study aimed to investigate the frequency of CS and its clinical and functional effects on familial Mediterranean fever (FMF). A hundred FMF patients were included in this study. The presence of CS was investigated by the central sensitization inventory (CSI). In addition to the detailed clinical features of patients and genetic mutations, quality of life, disability, sleep disorders, depression, anxiety, and fibromyalgia frequency were examined to evaluate the negative effects of CS on the individual. Patients were divided into groups according to the presence and severity of CS, and their results were compared. Correlation and multivariate regression analysis were performed to investigate the association of CS  with selected demographic and clinical parameters. The mean CSI was 37.72 (SD: 19.35), and thirty-eight (38%) patients had CS. Sacroiliitis occurred in 11 patients (11%), amyloidosis in 3 (3%), and erysipelas-like erythema in 11 (11%). The most prevalent genetic mutation was M694/any compound heterogeneous (35.7%), followed by M69V homogeneous (30%). Regarding comparing the patients with and without CS, the number of attacks, disease activity, daily colchicine dose, and all investigated comorbidities were significantly higher in the patients with CS (p < 0.05). In regression analysis, gender, colchicine dose and sleep disturbance were detected as related parameters with CS (OR (95% CI): 6.05 (1.39; 26.32), p: 0.017, OR (95% CI): 6.69 (1.65; 27.18), p: 0.008, OR (95% CI): 1.35 (1.35; 1.59), p: 0.001, respectively). Concomitant pain sensitization appears to be related to FMF patients' clinical and functional characteristics. These results suggest taking into consideration CS in the management of FMF patients.

Network analysis in aged C. elegans reveals candidate regulatory genes of ageing

Ageing is a biological process guided by genetic and environmental factors that ultimately lead to adverse outcomes for organismal lifespan and healthspan. Determination of molecular pathways that are affected with age and increase disease susceptibility is crucial. The gene expression profile of the ideal ageing model, namely the nematode Caenorhabditis elegans mapped with the microarray technology initially led to the identification of age-dependent gene expression alterations that characterize the nematode's ageing process. The list of differentially expressed genes was then utilized to construct a network of molecular interactions with their first neighbors/interactors using the interactions listed in the WormBase database. The subsequent network analysis resulted in the unbiased selection of 110 candidate genes, among which well-known ageing regulators appeared. More importantly, our approach revealed candidates that have never been linked to ageing before, thus suggesting promising potential targets/ageing regulators.

Familial Mediterranean fever: What associations to screen for?

Familial Mediterranean fever (FMF) is the most common and best known of hereditary recurrent fever or periodic fever syndromes. It was described in 1945 and genetically characterized in 1992. It is caused by a point mutation in the MEFV gene located on the short arm of chromosome 16. It is particularly frequent among Sephardic Jews, Armenians, Turks and Middle Eastern Arabs, where the prevalence can reach 1/2000 to 1/1000.

Recent publications described its frequent association with other diseases and/or syndromes, particularly those of autoimmune, genetic, and autoinflammatory origin.

The objective of this review is to familiarize healthcare professionals with the main associations to look for in patients followed for FMF. The early detection of these associations makes it possible to improve the management and the prognosis of patients with FMF.

Whole exome sequencing in unclassified autoinflammatory diseases: more monogenic diseases in the pipeline?

Objective

Autoinflammatory diseases (AIDs) are characterized by recurrent sterile systemic inflammation attacks. More than half of the patients remain genetically undiagnosed with next-generation sequencing panels for common AIDs. In this study, we aimed to define phenotype-genotype correlations in a cohort of unclassified AID patients via whole exome sequencing (WES).

Methods

Patients with features of AIDs were included in this study followed in the Department of Pediatric Rheumatology at Hacettepe University. They were first screened for MEFV with Sanger sequencing and then WES performed for the patients with clinically insignificant results. Pre-analysis of WES data was done by considering the 13 most common AID-related genes. Further bioinformatic analysis was performed if the patient remained genetically undiagnosed.

Results

The median age at disease onset was 1.2 years (range 0.2–16) and at the time of study recruitment was 14 years (range 3.5–17). In our cohort, WES provided a definite or probable disease-causing variant in 4 of 11 patients (36%). Heterozygous mutations for two of these genes were previously associated with neurological defects (ADAM17, TBK1), also homozygous ADAM17 mutations were observed in one family with neonatal inflammatory skin and bowel disease. Besides, two genes (LIG4, RAG1) were associated with immunodeficiency although the patients had presented with inflammatory features. Finally, for one patient, we associated a strong candidate gene (NLRC3) with autoinflammatory features.

Conclusion

WES strategy is cost-effective and provides substantial results for a selected group of undefined AID patients. Our results will contribute to the spectrum of unclassified AIDs.

Amand RP, Neuhausen SL, Shively JE. SNPs in inflammatory genes CCL11, CCL4 and MEFV in a fibromyalgia family study

BACKGROUND

Fibromyalgia (FM) is a chronic pain syndrome with a high incidence in females that may involve activation of the immune system. We performed exome sequencing on chemokine genes in a region of chromosome 17 identified in a genome-wide family association study.

METHODS AND FINDINGS

Exome sequence analysis of 100 FM probands was performed at 17p13.3-q25 followed by functional analysis of SNPs found in the chemokine gene locus. Missense SNPs (413) in 17p13.3-q25 were observed in at least 10 probands. SNPs rs1129844 in CCL11 and rs1719152 in CCL4 were associated with elevated plasma chemokine levels in FM. In a transmission disequilibrium test (TDT), rs1129844 was unequally transmitted from parents to their affected children (p< 0.0074), while the CCL4 SNP was not. The amino acid change (Ala23Thr), resulting from rs1129844 in CCL11, predicted to alter processing of the signal peptide, led to reduced expression of CCL11. The variant protein from CCL4 rs1719152 exhibited protein aggregation and a potent down-regulation of its cognate receptor CCR5, a receptor associated with hypotensive effects. Treatment of skeletal muscle cells with CCL11 produced high levels of CCL4 suggesting CCL11 regulates CCL4 in muscle. The immune association of FM with SNPs in MEFV, a chromosome 16 gene associated with recurrent fevers, had a p< 0.008 TDT for a combined 220 trios.

CONCLUSIONS

SNPs with significant TDTs were found in 36% of the cohort for CCL11 and 12% for MEFV, along with a protein variant in CCL4 (41%) that affects CCR5 down-regulation, supporting an immune involvement for FM.

[Familial Mediterranean fever]

Familial Mediterranean Fever (FMF) is the most frequent monogenic auto-inflammatory disease. FMF is an autosomal recessive disease, which affects populations from Mediterranean origin and is associated with MEFV gene mutations encoding for the protein pyrin. Pyrin activation enhances the secretion of interleukin 1 by myelo-monocytic cells. Main features of the disease are acute attacks of serositis mainly located on the abdomen, less frequently on chest and joints, accompanied by fever and biological inflammatory markers elevation. Usually attacks last 1 to 3 days and spontaneously stop. A daily oral colchicine intake of 1 to 2mg/day is able to prevent attack's occurrence, frequency, intensity and duration among most patients. Colchicine is also able to prevent the development of inflammatory amyloidosis, the most severe complication of FMF. This state of the art article will focus on the diagnosis of FMF, the treatment and an update on the pathophysiology including the recent described dominant form of MEFV-associated new auto-inflammatory diseases.

Gene Expression Factor Analysis to Differentiate Pathways Linked to Fibromyalgia, Chronic Fatigue Syndrome, and Depression in a Diverse Patient Sample

OBJECTIVE

To determine if independent candidate genes can be grouped into meaningful biologic factors, and whether these factors are associated with the diagnosis of chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FMS), while controlling for comorbid depression, sex, and age.

METHODS

We included leukocyte messenger RNA gene expression from a total of 261 individuals, including healthy controls (n = 61), patients with FMS only (n = 15), with CFS only (n = 33), with comorbid CFS and FMS (n = 79), and with medication-resistant (n = 42) or medication-responsive (n = 31) depression. We used exploratory factor analysis (EFA) on 34 candidate genes to determine factor scores and regression analysis to examine whether these factors were associated with specific diagnoses.

RESULTS

EFA resulted in 4 independent factors with minimal overlap of genes between factors, explaining 51% of the variance. We labeled these factors by function as 1) purinergic and cellular modulators, 2) neuronal growth and immune function, 3) nociception and stress mediators, and 4) energy and mitochondrial function. Regression analysis predicting these biologic factors using FMS, CFS, depression severity, age, and sex revealed that greater expression in factors 1 and 3 was positively associated with CFS and negatively associated with depression severity (Quick Inventory for Depression Symptomatology score), but not associated with FMS.

CONCLUSION

Expression of candidate genes can be grouped into meaningful clusters, and CFS and depression are associated with the same 2 clusters, but in opposite directions, when controlling for comorbid FMS. Given high comorbid disease and interrelationships between biomarkers, EFA may help determine patient subgroups in this population based on gene expression.

Update on Pyrin Functions and Mechanisms of Familial Mediterranean Fever

Mutations in the MEFV gene, which encodes the protein named pyrin (also called marenostrin or TRIM20), are associated with the autoinflammatory disease familial Mediterranean fever (FMF). Recent genetic and immunologic studies uncovered novel functions of pyrin and raised several new questions in relation to FMF pathogenesis. The disease is clinically heterogeneous reflecting the complexity and multiplicity of pyrin functions. The main functions uncovered so far include its involvement in innate immune response such as the inflammasome assemblage and, as a part of the inflammasome, sensing intracellular danger signals, activation of mediators of inflammation, and resolution of inflammation by the autophagy of regulators of innate immunity. Based on these functions, the FMF-associated versions of pyrin confer a heightened sensitivity to a variety of intracellular danger signals and postpone the resolution of innate immune responses. It remains to be demonstrated, however, what kind of selective advantage the heterozygous carriage conferred in the past to be positively selected and maintained in populations from the Mediterranean basin.

Update on the genetics of the fibromyalgia syndrome

Fibromyalgia syndrome (FMS), a condition characterized by chronic widespread pain and tenderness, is a complex condition considered to represent a paradigm of centralized pain. FMS has demonstrated a clear familial aggregation, and hence it is considered to have a genetic background. Multiple candidate-gene studies have been conducted in this field, focusing on target genes that play a role in the transmission and processing of pain. While many of these have focused in the past on markers related to neurotransmitter systems such as catecholamines (catechol-O-methyltransferase (COMT)) and serotonin, novel target genes have recently emerged. In addition, genome-wide sequencing scanning (genome-wide association study (GWAS)) is increasingly being harnessed for the study of chronic pain, including FMS. Micro RNAs are another novel field of research related to posttranscriptional inhibition of gene expression, which are currently regarding the pathogenesis of FMS.

Clinical evaluation of R202Q alteration of MEFV genes in Turkish children

To date, over 200 alterations have been reported in Mediterranean fever (MEFV) genes, but it is not clear whether all these alterations are disease-causing mutations. This study aims to evaluate the clinical features of the children with R202Q alteration. The medical records of children with R202Q alteration were reviewed retrospectively. A total of 225 children, with 113 males, were included. Fifty-five patients were heterozygous, 30 patients were homozygous for R202Q, and 140 patients were compound heterozygous. Classical familial Mediterranean fever (FMF) phenotype was present in 113 patients: 2 heterozygous and 7 homozygous R202Q, 46 double homozygous R202Q and M694V, and 58 compound heterozygous. The main clinical characteristics of the patients were abdominal pain in 71.5 %, fever in 37.7 %, arthralgia/myalgia in 30.2 %, arthritis in 10.2 %, chest pain in 14.6 % and erysipelas-like erythema in 13.3 %. The frequency of abdominal pain was significantly lower in patients with homozygous R202Q alteration (p = 0.021), whereas patients with heterozygous R202Q mutations, though not statistically significant, had a higher frequency of arthralgia/myalgia (40.0 %, p = 0.05). R202Q alteration of the MEFV gene leads to symptoms consistent with FMF in some cases. This alteration may be associated with a mild phenotype and shows phenotypic differences other than the common MEFV mutations.

NLRP3 inflammasome is activated in fibromyalgia: the effect of coenzyme Q10

AIMS

Fibromyalgia (FM) is a prevalent chronic pain syndrome characterized by generalized hyperalgesia associated with a wide spectrum of symptoms such as fatigue and joint stiffness. Diagnosis of FM is difficult due to the lack of reliable diagnostic biomarkers, while treatment is largely inadequate. We have investigated the role of coenzyme Q10 (CoQ10) deficiency and mitochondrial dysfunction in inflammasome activation in blood cells from FM patients, and in vitro and in vivo CoQ10 deficiency models.

RESULTS

Mitochondrial dysfunction was accompanied by increased protein expression of interleukin (IL)-1β, NLRP3 (NOD-like receptor family, pyrin domain containing 3) and caspase-1 activation, and an increase of serum levels of proinflammatory cytokines (IL-1β and IL-18). CoQ10 deficiency induced by p-aminobenzoate treatment in blood mononuclear cells and mice showed NLRP3 inflammasome activation with marked algesia. A placebo-controlled trial of CoQ10 in FM patients has shown a reduced NLRP3 inflammasome activation and IL-1β and IL-18 serum levels.

INNOVATION

These results show an important role for the NLRP3 inflammasome in the pathogenesis of FM, and the capacity of CoQ10 in the control of inflammasome.

CONCLUSION

These findings provide new insights into the pathogenesis of FM and suggest that NLRP3 inflammasome inhibition represents a new therapeutic intervention for the disease.

Discovery of potential new gene variants and inflammatory cytokine associations with fibromyalgia syndrome by whole exome sequencing

Fibromyalgia syndrome (FMS) is a chronic musculoskeletal pain disorder affecting 2% to 5% of the general population. Both genetic and environmental factors may be involved. To ascertain in an unbiased manner which genes play a role in the disorder, we performed complete exome sequencing on a subset of FMS patients. Out of 150 nuclear families (trios) DNA from 19 probands was subjected to complete exome sequencing. Since >80,000 SNPs were found per proband, the data were further filtered, including analysis of those with stop codons, a rare frequency (<2.5%) in the 1000 Genomes database, and presence in at least 2/19 probands sequenced. Two nonsense mutations, W32X in C11orf40 and Q100X in ZNF77 among 150 FMS trios had a significantly elevated frequency of transmission to affected probands (p = 0.026 and p = 0.032, respectively) and were present in a subset of 13% and 11% of FMS patients, respectively. Among 9 patients bearing more than one of the variants we have described, 4 had onset of symptoms between the ages of 10 and 18. The subset with the C11orf40 mutation had elevated plasma levels of the inflammatory cytokines, MCP-1 and IP-10, compared with unaffected controls or FMS patients with the wild-type allele. Similarly, patients with the ZNF77 mutation have elevated levels of the inflammatory cytokine, IL-12, compared with controls or patients with the wild type allele. Our results strongly implicate an inflammatory basis for FMS, as well as specific cytokine dysregulation, in at least 35% of our FMS cohort.

The phenotypic and genetic signatures of common musculoskeletal pain conditions

Musculoskeletal pain conditions, such as fibromyalgia and low back pain, tend to coexist in affected individuals and are characterized by a report of pain greater than expected based on the results of a standard physical evaluation. The pathophysiology of these conditions is largely unknown, we lack biological markers for accurate diagnosis, and conventional therapeutics have limited effectiveness. Growing evidence suggests that chronic pain conditions are associated with both physical and psychological triggers, which initiate pain amplification and psychological distress; thus, susceptibility is dictated by complex interactions between genetic and environmental factors. Herein, we review phenotypic and genetic markers of common musculoskeletal pain conditions, selected based on their association with musculoskeletal pain in previous research. The phenotypic markers of greatest interest include measures of pain amplification and 'psychological' measures (such as emotional distress, somatic awareness, psychosocial stress and catastrophizing). Genetic polymorphisms reproducibly linked with musculoskeletal pain are found in genes contributing to serotonergic and adrenergic pathways. Elucidation of the biological mechanisms by which these markers contribute to the perception of pain in these patients will enable the development of novel effective drugs and methodologies that permit better diagnoses and approaches to personalized medicine.

Interaction of IL-1β and P2X(3) receptor in pathologic masseter muscle pain

The exact mechanism underlying chronic masseter muscle pain, a conspicuous symptom in temporomandibular disorder, remains unclear. We investigated whether expression of P2X3 receptor (P2X3R) is involved in mechanical hyperalgesia after contraction of masseter muscle (CMM). As compared with sham rats, the head-withdrawal threshold (HWT) to mechanical pressure stimulation of masseter muscle (MM) (but not after similar stimulation of facial skin) was significantly lower, and IL-1β level was significantly higher, in CMM rats on day 7 after CMM. The mean percentage of FG-labeled P2X3R-positive neurons was significantly increased in TG following successive IL-1β injections into the MM for 7 days. Successive administration of an IL-1β receptor-antagonist into the MM attenuated the increase of P2X3-IR cells in the TG. ATP release from MM after 300-g pressure stimulation of MM was also significantly enhanced after CMM. Administration into MM of the selective P2X3,2/3 receptor antagonist A-317491 attenuated the decrement of HWT in CMM rats. A significant increase in HWT was also observed at 30 min after A-317491 (60 µg) injection in IL-1β-injected rats. These findings suggest that P2X3R expression associated with enhanced IL-1β expression and ATP release in MM has a possible important role in MM mechanical hyperalgesia after excessive muscular contraction.

Significance of MEFV gene R202Q polymorphism in Turkish familial Mediterranean fever patients

OBJECTIVE

Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent attacks of fever and inflammation in the peritoneum, synovium, or pleura, accompanied by pain. The disease is associated with mutations in the Mediterranean fever (MEFV) gene, which encodes for the pyrin protein. The aim of this study was to explore the frequency and clinical significance of the R202Q (c.605G>A) polymorphism in exon 2 of the MEFV gene in a cohort of Turkish patients with FMF.

METHODS

The study included 191 patients with FMF and 150 healthy controls. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay for the MEFV gene R202Q polymorphism.

RESULTS

The genotype and allele frequencies of R202Q polymorphism showed a statistically significant difference between FMF patients and controls (p<0.0001 and p=0.0004, respectively) and especially the homozygous AA genotype was significantly higher in FMF patients than healthy controls (p=0.0002; odds ratio=6.27; 95% CI=2.1-18.3). However no significant association was observed between clinical and demographic features of FMF patients and R202Qpolymorphism.

CONCLUSION

The results of this study showed that there was a high association between MEFV gene R202Q polymorphism and FMF. R202Q polymorphism should be included in routine molecular diagnosis of FMF patients.

Psychoneuroimmunological relationships in women with fibromyalgia

INTRODUCTION

The purpose of this pilot study was to characterize the relationships among perceived stress, pain, fatigue, depression, anxiety, biomarkers, and functional status in women with fibromyalgia syndrome (FMS) using a psychoneuroimmunological (PNI) framework.

MATERIALS AND METHOD

Using a cross-sectional, correlational design, the authors asked 50 women diagnosed with FMS to complete the Perceived Stress Scale (PSS), Brief Pain Inventory (BPI), Brief Fatigue Inventory (BFI), Center for Epidemiological Studies-Depression scale, State-Trait Anxiety Inventory (STAI), and Functional Impact Questionnaire. The authors analyzed plasma levels of 17 cytokines using a BioPlex® assay and levels of C-reactive protein (CRP) using a high-sensitivity enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared to published guidelines (>3 mg/L reflects high inflammation), CRP levels were elevated in participating women. Perceived stress demonstrated positive correlations with pain, fatigue, depression, anxiety, and functional status and negative correlations with monocyte chemotactic protein (MCP)-1(r = -.30) and interleukin-1 beta (IL-1β; r = -.29). Pain severity correlated with macrophage inflammatory protein (MIP)-1β (r = .29), and pain interference negatively correlated with IL-1β (r = -.30). Fatigue negatively correlated with IL-1β (r = -.32), interleukin-10 (IL-10; r = -.31), and granulocyte colony-stimulating factor (G-CSF; r = -.31). Depressive symptoms correlated with CRP (r = .31).

DISCUSSION

Relationships among perceived stress and symptoms supported the PNI framework. Study findings are similar to previous studies showing that cytokines in persons with FMS do not show a consistent pattern. The elevated CRP levels suggest higher levels of generalized inflammation in the sample and provide evidence for continued development of biobehavioral interventions to address both symptoms and their biological markers over time.

Systematic review with meta-analysis: cytokines in fibromyalgia syndrome

BACKGROUND

To perform a systematic review and meta-analysis on cytokine levels in patients with fibromyalgia syndrome (FMS).

METHODS

Through December 2010 we systematically reviewed the databases PubMed, MEDLINE, and PsycINFO and screened the reference lists of 22 review articles for suitable original articles. Original articles investigating cytokines in patients with FMS were included. Data were extracted by two independent authors. Differences of the cytokine levels of FMS patients and controls were summarized by standardized mean differences (SMD) using a random effects model. Study quality was assessed applying methodological scores: modified Center of Evidence Based Medicine, Newcastle-Ottawa-Scale, and Würzburg Methodological Quality Score.

RESULTS

Twenty-five articles were included investigating 1255 FMS patients and 800 healthy controls. Data of 13/25 studies entered meta-analysis. The overall methodological quality of studies was low. The results of the majority of studies were not comparable because methods, investigated material, and investigated target cytokines differed. Systematic review of the selected 25 articles revealed that FMS patients had higher serum levels of interleukin (IL)-1 receptor antagonist, IL-6, and IL-8, and higher plasma levels of IL-8. Meta-analysis of eligible studies showed that FMS patients had higher plasma IL-6 levels compared to controls (SMD = -0.34 [-0.64, -0.03] 95% CI; p = 0.03). The majority of investigated cytokines were not different between patients and controls.

CONCLUSIONS

The pathophysiological role of cytokines in FMS is still unclear. Studies of higher quality and with higher numbers of subjects are needed.

Beyond the serotonin hypothesis: mitochondria, inflammation and neurodegeneration in major depression and affective spectrum disorders

For many years, a deficiency of monoamines including serotonin has been the prevailing hypothesis on depression, yet research has failed to confirm consistent relations between brain serotonin and depression. High degrees of overlapping comorbidities and common drug efficacies suggest that depression is one of a family of related conditions sometimes referred to as the "affective spectrum disorders", and variably including migraine, irritable bowel syndrome, chronic fatigue syndrome, fibromyalgia and generalized anxiety disorder, among many others. Herein, we present data from many different experimental modalities that strongly suggest components of mitochondrial dysfunction and inflammation in the pathogenesis of depression and other affective spectrum disorders. The three concepts of monoamines, energy metabolism and inflammatory pathways are inter-related in many complex manners. For example, the major categories of drugs used to treat depression have been demonstrated to exert effects on mitochondria and inflammation, as well as on monoamines. Furthermore, commonly-used mitochondrial-targeted treatments exert effects on mitochondria and inflammation, and are increasingly being shown to demonstrate efficacy in the affective spectrum disorders. We propose that interactions among monoamines, mitochondrial dysfunction and inflammation can inspire explanatory, rather than mere descriptive, models of these disorders.

Monogenic autoinflammatory diseases: new insights into clinical aspects and pathogenesis

PURPOSE OF REVIEW

The genetic and clinical characterizations of monogenic autoinflammatory syndromes have led to ground breaking insights into the regulation of inflammatory responses to endogenous and exogenous inducers or triggers of inflammation and continue to uncover key inflammatory pathways of the innate immune system. This article summarizes recent progress in the clinical aspects and understanding of the pathogenesis of this growing spectrum of diseases.

RECENT FINDINGS

The understanding of the spectrum of organ manifestations in autoinflammation was expanded by the discovery of two novel monogenic diseases both caused by the absence of an anti-inflammatory signal and added evidence that increased IL-1 signaling can cause aseptic osteolytic bone lesions and that the absence of IL-10 signaling causes inflammatory enterocolitis in neonates. New knock in animal models for TNF-receptor-associated periodic syndrome, and familial Mediterranean fever and cryopyrin-associated periodic syndromes allow insights into the complexity of the dysregulated immune pathways. Exploring 'triggers' of the NLRP3 inflammasome spurred studies of tissue inflammation in diseases including gout and those that previously have not been considered inflammatory in nature such as diabetes, fibrosing lung disease and possibly coronary artery disease.

SUMMARY

The genetic characterization of a growing number of monogenic autoinflammatory diseases has provided important insights into the phenotypic expression of single gene disorders and the complexity of the dysregulated inflammatory pathways leading to clinical disease. Knowledge obtained from these disorders is pertinent to a number of common disorders and provides new targets for drug development.