Laurence Cuisset

New Mutations of CIAS1 That Are Responsible for Muckle-Wells Syndrome and Familial Cold Urticaria: A Novel Mutation Underlies Both Syndromes

Mutations of CIAS1 have recently been shown to underlie familial cold urticaria (FCU) and Muckle-Wells syndrome (MWS), in three families and one family, respectively. These rare autosomal dominant diseases are both characterized by recurrent inflammatory crises that start in childhood and that are generally associated with fever, arthralgia, and urticaria. The presence of sensorineural deafness that occurs later in life is characteristic of MWS. Amyloidosis of the amyloidosis-associated type is the main complication of MWS and is sometimes associated with FCU. In FCU, cold exposure is the triggering factor of the inflammatory crisis. We identified CIAS1 mutations, all located in exon 3, in nine unrelated families with MWS and in three unrelated families with FCU, originating from France, England, and Algeria. Five mutations--namely, R260W, D303N, T348M, A439T, and G569R--were novel. The R260W mutation was identified in two families with MWS and in two families with FCU, of different ethnic origins, thereby demonstrating that a single CIAS1 mutation may cause both syndromes. This result indicates that modifier genes are involved in determining either a MWS or a FCU phenotype. The finding of the G569R mutation in an asymptomatic individual further emphasizes the importance of such modifier a gene (or genes) in determining the disease phenotype. Identification of this gene (or these genes) is likely to have significant therapeutic implications for these severe diseases.

The infevers autoinflammatory mutation online registry: update with new genes and functions.

Infevers (Internet Fevers; http://fmf.igh.cnrs.fr/ISSAID/infevers), a website dedicated to mutations responsible for hereditary autoinflammatory diseases, was created in 2002 and has continued to evolve. This new version includes eight genes; six were already present: MEFV, MVK, TNFRSF1A, NLRP3, NOD2, PSTPIP1, and two are new, LPIN2 and NLRP7. Currently, Infevers contains over 540 sequence variants. Several new database functions were recently instituted. The website now accepts confidential data and complex alleles. For each gene, a newly created menu offers: 1) a tabular list of the variants that can be sorted by several parameters; 2) a gene graph providing a schematic representation of the variants along the gene; 3) statistical analysis of the data according to the phenotype, alteration type, and location of the mutation in the gene; 4) the cDNA and gDNA sequences of each gene, showing the nucleotide changes along the sequence, with a color‐based code highlighting the gene domains, the first ATG, and the termination codon; and 5) a “download” menu making all tables and figures available for the users, which, except for the gene graphs, are all automatically generated and updated upon submission of the variants. Finally, the entire database was curated to comply with the HUGO Gene Nomenclature Committee (HGNC) and HGVS nomenclature guidelines, and wherever necessary, an informative note was provided. Infevers has already proven useful for the scientific community with a mean number of visits per month of 200 in 2002 and 800 in 2007, and its new design will lead to a more comprehensive comparative analysis and interpretation of auto‐inflammatory sequence variants. Hum Mutat 29(6), 803–808, 2008. Published 2008, Wiley‐Liss, Inc.

Molecular analysis of MVK mutations and enzymatic activity in hyper-IgD and periodic fever syndrome

Hyperimmunoglobulinaemia D and periodic fever syndrome (HIDS) is an autosomal recessive inflammatory disorder characterised by recurrent episode of fever associated with lymphadenopathy, abdominal distress, joint involvement and skin lesions. We recently demonstrated that mutations in the mevalonate kinase gene (MVK) are associated with HIDS. Direct DNA sequencing was done to screen the entire coding region of MVK in 25 unrelated patients with HIDS. Mutations were detected in the coding region of the gene including 11 missense mutations, one deletion, the absence of expression of one allele, as well as three novel polymorphisms. Seven of these mutations are novel. The large majority of the patients were compound heterozygotes for two mutations. Of these, V377I (G→A) is the most common mutation occurring in 20 unrelated patients and was found to be associated with I268T in six patients. Mutations were associated with a decrease of mevalonate kinase (MK) (ATP:mevalonate 5-phosphotransferase, EC 2.7.I.36) enzymatic activity but not as profound as in mevalonic aciduria, a syndrome also caused by a deficient activity of MK. In HIDS the mutations are located all along the protein which is different from mevalonic aciduria where MK mutations are mainly clustered to a same region of the protein. On the basis of this study, we propose that the diagnostic screen of MVK in HIDS should be first directed on V377I and I268T mutations. Three patients are also described to illustrate the genotypic and phenotypic overlap with mevalonic aciduria.

Mevalonate Kinase Deficiency: A Survey of 50 Patients

OBJECTIVE: The goal of this study was to describe the spectrum of clinical signs of mevalonate kinase deficiency (MKD). METHODS: This was a retrospective French and Belgian study of patients identified on the basis of MKD gene mutations. RESULTS: Fifty patients from 38 different families were identified, including 1 asymptomatic patient. Symptoms began during the first 6 months of life in 30 patients (60%) and before the age of 5 years in 46 patients (92%). Symptoms consisted of febrile diarrhea and/or rash in 23 of 35 patients (66%). Febrile attacks were mostly associated with lymphadenopathy (71%), diarrhea (69%), joint pain (67%), skin lesions (67%), abdominal pain (63%), and splenomegaly (63%). In addition to febrile attacks, 27 patients presented with inflammatory bowel disease, erosive polyarthritis, Sjögren syndrome, and other chronic neurologic, renal, pulmonary, endocrine, cutaneous, hematologic, or ocular symptoms. Recurrent and/or severe infections were observed in 13 patients, hypogammaglobulinemia in 3 patients, and renal angiomyolipoma in 3 patients. Twenty-nine genomic mutations were identified; the p.Val377Ile mutation was the most frequently found (29 of 38 families). Three patients died of causes related to MKD. The disease remained highly active in 17 of the 31 surviving symptomatic patients followed up for >5 years, whereas disease activity decreased over time in the other 14 patients. Interleukin 1 antagonists were the most effective biological agents tested, leading to complete or partial remission in 9 of 11 patients. CONCLUSION: MKD is not only an autoinflammatory syndrome but also a multisystemic inflammatory disorder, a possible immunodeficiency disorder, and a condition that predisposes patients to the development of renal angiomyolipoma.

Genetic Linkage of the Muckle-Wells Syndrome to Chromosome 1q44

The Muckle-Wells syndrome (MWS) is a hereditary inflammatory disorder characterized by acute febrile inflammatory episodes comprising abdominal pain, arthritis, and urticaria. Progressive nerve deafness develops subsequently, and, after several years, the disease is complicated by multiorgan AA-type amyloidosis (i.e., amyloidosis derived from the inflammatory serum amyloid-associated protein) (MIM 191900) with renal involvement and end-stage renal failure. The mode of inheritance is autosomal dominant, but some sporadic cases have also been described. No specific laboratory findings have been reported. The genetic basis of MWS is unknown. Using a genomewide search strategy in three families, we identified the locus responsible for MWS, at chromosome 1q44. Our results indicate that the gene is located within a 13.9-cM region between markers D1S2811 and D1S2882, with a maximum two-point LOD score of 4. 66 (recombination fraction.00) at D1S2836 when full penetrance is assumed. Further identification of the specific gene that is responsible for MWS will therefore provide the first biological element for characterizing MWS, other than doing so on the basis of its variable clinical expression.

Molecular analysis of the mevalonate kinase gene in a cohort of patients with the hyper-igd and periodic fever syndrome: its application as a diagnostic tool.

Periodic fever encompasses a group of disorders characterized by limited periods of fever that recur for years in otherwise healthy persons. These fevers are highly discouraging and frustrating for physicians and patients alike because elaborate clinical investigations frequently fail to substantiate the diagnosis (1, 2). Over the past few years, several distinct subtypes of periodic fever have emerged (3-7), one of which is the hyper-IgD and periodic fever syndrome (HIDS) (8). Patients with HIDS experience recurrent episodes of high fever accompanied by lymphadenopathy, abdominal distress, and arthralgia (9, 10); the episodes last several days and recur every few weeks. Most patients are from western Europe, but patients have also been identified in the United States (11). In patients with HIDS, levels of serum IgD are constantly elevated. The diagnosis is based on clinical grounds and elevated serum IgD levels but requires a high index of suspicion. Two studies that used different genetic methods established that mutations in mevalonate kinase cause HIDS (12, 13). Early in the process of cholesterol synthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase catalyzes the production of mevalonic acid, which is then phosphorylated by the enzyme mevalonate kinase. One study searched the genome by using blood samples from members of affected HIDS families and established linkage with the locus for mevalonate kinase (12). Another study detected minor elevated urinary excretions of mevalonic acid and an impaired mevalonate kinase activity in a patient with HIDS (13). Each study independently discovered disease-associated mutations in the mevalonate kinase gene in affected patients. To ascertain the role of mevalonate kinase in HIDS, we searched for mutations in the gene and examined the enzyme activity of mevalonate kinase in 54 patients with the typical clinical and laboratory features of HIDS. Methods Patients Patients were selected on the basis of previous inclusion in the Nijmegen HIDS registry, an international database that includes data on 176 patients (9), and availability of DNA and lymphoblast cell lines. All patients met the following criteria: repeated episodes of fever (body temperature > 38.5 C) with biochemical evidence of an acute-phase response, including elevated erythrocyte sedimentation rate and leukocytosis; a constantly elevated serum IgD level (>100 kIU/mL), as measured on two occasions; and one or more of the following symptoms during attacksMlymphadenopathy, abdominal distress (vomiting, diarrhea, pain), skin lesions (erythematous macules and papules), arthralgia, or splenomegaly. We enrolled 54 patients from 41 families and 12 unaffected parents of patients. Our sample included patients of Dutch (n = 42), French (n = 4), British (n = 2), Czech (n = 2), Spanish (n = 2), Belgian (n = 1), and Turkish (n =1) nationality. Patients and family members underwent a thorough clinical examination during and between attacks. Blood samples were collected during and between fever episodes; laboratory results are from samples taken during remissions unless otherwise indicated. The medical ethical committee of the University Medical Center St. Radboud, Nijmegen, the Netherlands, formally approved this study. All patients gave informed consent for participation in the study. Screening of Mutations in the Mevalonate Kinase Gene Immortalized lymphoblast cell lines were generated by in vitro infection of lymphocytes by EpsteinBarr virus. These cell lines were used to extract ribonucleic acid, and complementary DNA was produced by using standard techniques. The complete coding region of the mevalonate kinase gene was amplified by performing polymerase chain reactions, and mutations were detected by using fluorescent sequencing, as described elsewhere (12, 14). Mevalonate Kinase Enzyme Analysis Mevalonate kinase enzyme activity was determined in 36 of the 54 patients with HIDS and 12 parents of patients with classic HIDS who are (obligate) heterozygous for the mevalonate kinase mutation. We employed a radiometric assay by using extracts of cultured lymphocytes from EpsteinBarr immortalized cell lines, as described elsewhere (15, 16). Statistical Analysis We performed statistical analyses by using the chi-square test, the unpaired nonparametric MannWhitney U test, and nonparametric Spearman correlation coefficients. Analyses were performed by using GraphPad Prism software, version 3.02 for Windows (GraphPad Software, Inc., San Diego, California). The significance level, the probability of a type I error, was set at 0.05. Results Mutation Analysis Mutation analysis revealed mutations in the gene for mevalonate kinase in 41 of the 54 tested patients, as described elsewhere (12, 14). We detected a missense mutationa 1base pair exchange in the gene resulting in an amino acid change in the proteinin 64 of 82 examined alleles. A deletion of a small number of base pairs was detected in 5 alleles, and RNA was absent from 7 alleles. The pertinent mutation could not be determined in 6 alleles. Thirty-seven of the 41 patients with gene mutations were compound heterozygotes, which means they possess a different mutation on each allele of the gene. Despite exhibiting the clinical phenotype of HIDS and completely fulfilling the clinical criteria, 13 of the 54 patients had no detectable mutation of the mevalonate kinase gene. To detect whether mutations in the mevalonate kinase gene result in a different clinical picture, we separated our cohort into two groups: We designated patients with HIDS who met the clinical criteria for HIDS and carried mutations in the mevalonate kinase gene as having classic-type HIDS and designated the mutation-negative patients who met the clinical criteria for HIDS as having variant-type HIDS. Mevalonate Kinase Enzyme Activity The top part of the Figure shows the mevalonate kinase enzyme activity in individual patients with HIDS. The mean enzyme activity (SD) in patients with classic-type HIDS (0.42 0.25 nmol/min per mg of protein) was greatly depressed compared with that of patients who had variant-type HIDS (2.8 1.3 nmol/min per mg of protein) (P<0.001). In both groups, no significant correlations were found between enzyme activity and clinical disease severity, as measured in number of febrile days per year (r = 0.06 [P>0.2] for classic-type HIDS; r = 0.15 [P>0.2] for variant-type HIDS), or between enzyme activity and IgD levels (r = 0.02 for classic-type vs. r = 0.11 for variant-type [P>0.2 for both comparisons]). Participants who had children with classic-type HIDS and who were heterozygous for the mevalonate kinase mutation had a mean enzyme activity (1.7 0.77 nmol/min per mg of protein) that was lower than that of patients who had variant-type HIDS (P=0.008) but was significantly higher than that of their affected offspring (P<0.001). Figure. Mevalonate kinase enzyme activity and IgD levels in patients with classic-type or variant-type hyper-IgD and periodic fever syndrome (HIDS). Top. squares circles Bottom. Clinical Phenotype and Laboratory Values The Table depicts the pertinent clinical variables in the classic-type and variant-type HIDS groups. Age at onset of febrile attacks was greater in patients with variant-type HIDS. Compared with patients who had classic-type HIDS, patients with variant-type HIDS tended to have longer attacks (mean duration, 6.9 5.7 days for variant-type vs. 4.7 1.7 days for classic-type) and longer attack-free intervals (mean duration, 9.3 9.2 weeks for variant-type vs. 5.6 3.8 weeks for classic-type), although these differences were not statistically significant (P>0.2 for both comparisons). Of the 13 patients with variant-type HIDS, 1 patient had a brother and mother with similar symptoms, and 1 patient had an affected brother and daughter. As shown in the Table, patients with classic-type HIDS were more likely to have several types of accompanying symptoms. Table. Characteristics of Patient with Classic-Type or Variant-Type Hyper-IgD and Periodic Fever Syndrome The intensity of the acute-phase response during attacks was greater in patients with classic-type HIDS, as evidenced by a significantly higher erythrocyte sedimentation rate (Table). Laboratory Values Levels of IgA and IgG3were higher and IgG4 values were lower in patients with classic-type HIDS than in patients with variant-type HIDS. Although both groups of patients had high serum levels of IgD, the levels in patients with classic-type HIDS greatly exceeded those in patients with variant-type HIDS (Figure, bottom). However, in two affected siblings of separate patients with classic-type HIDS, we detected low values of IgD, although both patients carried the same mutations, had typical HIDS attacks, and had depressed activity of the mevalonate kinase enzyme similar to that seen in their affected sibling. Furthermore, no significant correlation was found between level of IgD and mevalonate kinase enzyme activity or between IgD levels and the number of febrile days per year (r = 0.05 [P>0.2] in classic-type; r = 0.46 [P=0.11] in variant-type). Discussion Recent efforts in localization and positional cloning identified mevalonate kinase as the causative gene in HIDS (12, 13). This enabled us to develop and evaluate a molecular genetic test of the mevalonate kinase gene as a diagnostic tool for HIDS. We detected disease-associated mutations in 76% of patients in a cohort of 54 patients. Most patients were compound heterozygotes, which means that they carried a different mutation on each allele of the mevalonate kinase gene. The mutations had clear physiologic consequences, such as considerably decreased activity of the enzyme mevalonate kinase in cultured lymphoblasts. We could delineate a substantial subgroup (24%) of our patient sample who had the typical clinical presentation of HIDS but lacked mutations in the mevalonate kinase gene. This suggests that there is genetic heterogeneity among

Mutations in the autoinflammatory cryopyrin-associated periodic syndrome gene: epidemiological study and lessons from eight years of genetic analysis in France

Background Cryopyrin-associated periodic syndromes (CAPS) consist of a continuum of autoinflammatory diseases caused by a defect in interleukin 1β regulation. Although symptoms may vary widely, the discovery, in 2001, of the gene involved (NLRP3) has dramatically helped diagnosis. Objectives To define the spectrum and prevalence of NLRP3 mutations in France and to delineate initial criteria before molecular analysis. Methods Retrospective review (2001–9) of genetic analysis data and request forms of patients living in France with an NLRP3 mutation since the set up of CAPS molecular diagnosis by the three French laboratories providing this test (GenMAI network). Results Over 800 analyses of this gene have been conducted, identifying 135 cases with an NLRP3 mutation (55 probands; 33 multiplex families); the estimated prevalence in France was equal to 1/360 000. A total of 21 different sequence variants were detected, among which four are common and nine are new mutations. Conclusions Although the number of NLRP3 test requests has doubled over the past 5 years, genetic screening has not contributed to enhanced detection of new index cases each year. There are two possible reasons for this: (i) no clinical prerequisite for genetic diagnosis and (ii) few new large families are now identified (unlike the initial study based on a selection by linkage). A set of initial clinical criteria have been drawn up which it is recommended should be fulfilled before a patient is tested: at least three recurrent bouts, age at disease onset < 20 years and elevated levels of C-reactive protein, especially in individuals with urticaria and moderate fever.

The Effects of Sodium Butyrate on Transcription Are Mediated through Activation of a Protein Phosphatase

In this study we have investigated the molecular mechanism by which sodium butyrate modulates gene expression when added to cultured cells. As a model system we used hepatoma tissue culture cells in which sodium butyrate treatment increases histone H1° mRNA level and decreases c-myc mRNA level. Because we observed that stimulation of histone H1° gene expression could take place in the absence of protein neosynthesis, we hypothesized that sodium butyrate induced a post-translational modification of a factor involved in the transcription process. Using different types of well known kinase and phosphatase inhibitors, we studied the implication of kinase or phosphatase activity in this pathway. Interestingly, cell treatment with potent serine-threonine-phosphatase inhibitors, calyculin A or okadaic acid, prevented the regulation of both histone H1° and c-myc gene expressions by sodium butyrate. On the other hand, the tyrosine phosphatase inhibitor, vanadate, or the protein kinase C inhibitor, staurosporine, did not significantly modify sodium butyrate effects. Using protein phosphatase 1 and 2A forin vitro assays, we found a 45% increase of phosphatase activity after cell treatment by sodium butyrate, possibly due to a protein phosphatase 1-type protein phosphatase. These data strongly suggest that signaling pathway(s) triggered by sodium butyrate to modulate gene expression involve(s) a serine-threonine-phosphatase activity.

A Clinical Criterion to Exclude the Hyperimmunoglobulin D Syndrome (Mild Mevalonate Kinase Deficiency) in Patients with Recurrent Fever

Objective. The hyperimmunoglobulin D syndrome (HIDS) is an autosomal recessive autoinflammatory disease caused by mutations in the mevalonate kinase gene. Our objective was to define a clinical criterion able to exclude HIDS without the need of genetic testing. Methods. A recursive partitioning algorithm was applied to derive the clinical criterion in 149 patients with genetic testing in a French laboratory, among whom 35 had HIDS. The criterion was validated in 93 patients with genetic testing in a Dutch laboratory, among whom 28 had HIDS. Results. The most discriminatory composite clinical criterion satisfied by all patients with HIDS in the derivation group was [onset age < 5 years old OR (joint pain during attacks AND length of attacks < 14 days)]. It had a sensitivity of 100% (95% confidence interval 88% to 100%) and a specificity of 28% (95% CI 17% to 40%) in the validation group. If genetic testing had been limited to patients fulfilling this criterion, 18 tests (19%) would have been avoided in this highly selected validation sample, without missing a single patient with HIDS. Conclusion. Even among patients already selected by expert physicians, this criterion could help prevent unnecessary genetic testing, which is resource- and time-consuming.

Specific increase in caspase-1 activity and secretion of IL-1 family cytokines: a putative link between mevalonate kinase deficiency and inflammation

The mevalonate kinase deficiency (MKD), including hyperimmunoglobulinemia D periodic fever syndrome (HIDS) and the more severe mevalonic aciduria are rare, autosomal recessive, autoinflammatory diseases belonging to the hereditary periodic fever (HPF) family. Other members include: familial mediterranean fever (FMF), the cryopyrin-associated periodic syndromes (CAPS) and TNFR-associated periodic syndromes (TRAPS). MKD is caused by mutations in the gene encoding mevalonate kinase (MK), an enzyme of the cholesterol pathway, leading to its inactivation. The molecular mechanisms linking MKD and abnormalities of isoprenoid biosynthesis to cytokine production and inflammation have yet to be fully elucidated. Statins, which are extensively prescribed for lowering cholesterol, are potent inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase, the enzyme directly upstream of MK. In this review, we discuss recent reports demonstrating that in vitro inhibition of the mevalonate pathway by statins specifically increases the production, by activated monocytes, of cytokines of the IL-1 family, by enhancing caspase-1 activity, the enzyme responsible for IL-1beta and IL-18 maturation. The molecular mechanisms involve geranylgeranylation and the enhancement of the activity of G proteins such as Rac-1. Interestingly, activated fibroblasts from MKD patients secrete more IL-1beta than fibroblasts from healthy donors. Taken together, these data highlight the specific enhancement of the IL-1 family of cytokines, the maturation of which is caspase-1-dependent in MKD. Finally, the spectacular decrease in febrile attacks in patients with severe HIDS under IL-1 receptor antagonist (anakinra) treatment, reinforces this hypothesis. Deregulated caspase-1 activation could be responsible for the inflammatory component of MKD, thereby mechanistically linking MKD to FMF and CAPS through cytokines of the IL-1 family.