Skewed X-chromosome inactivation drives the proportion of DNAAF6-defective airway motile cilia and variable expressivity in primary ciliary dyskinesia.

BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare airway disorder caused by defective motile cilia. Only male patients have been reported with pathogenic mutations in X-linked DNAAF6, which result in the absence of ciliary dynein arms, whereas their heterozygous mothers are supposedly healthy. Our objective was to assess the possible clinical and ciliary consequences of X-chromosome inactivation (XCI) in these mothers. METHODS: XCI patterns of six mothers of male patients with DNAAF6-related PCD were determined by DNA-methylation studies and compared with their clinical phenotype (6/6 mothers), as well as their ciliary phenotype (4/6 mothers), as assessed by immunofluorescence and high-speed videomicroscopy analyses. The mutated X chromosome was tracked to assess the percentage of cells with a normal inactivated DNAAF6 allele. RESULTS: The mothers' phenotypes ranged from absence of symptoms to mild/moderate or severe airway phenotypes, closely reflecting their XCI pattern. Analyses of the symptomatic mothers' airway ciliated cells revealed the coexistence of normal cells and cells with immotile cilia lacking dynein arms, whose ratio closely mirrored their XCI pattern. CONCLUSION: This study highlights the importance of searching for heterozygous pathogenic DNAAF6 mutations in all female relatives of male PCD patients with a DNAAF6 defect, as well as in females consulting for mild chronic respiratory symptoms. Our results also demonstrate that about one-third-ranging from 20% to 50%-normal ciliated airway cells sufficed to avoid severe PCD, a result paving the way for gene therapy.

Pathogenic variants in the NLRP3 LRR domain at position 861 are responsible for a boost-dependent atypical CAPS phenotype.

BACKGROUND: Cryopyrin-associated periodic syndrome (CAPS) is associated with NLRP3 pathogenic variants, mostly located in the NACHT (neuronal apoptosis inhibitor protein, MHC class 2 transcription activator, incompatibility locus protein from Podospora anserina, telomerase-associated protein) domain. Cold-induced urticarial rash is among the main clinical features. However, this study identified a series of 14 patients with pathogenic variants of the Y861 residue (p.Tyr861) of the LRR domain of NLRP3 and minimal prevalence of cold-induced urticarial rash. OBJECTIVES: This study aimed to address a possible genotype/phenotype correlation for patients with CAPS and to investigate at the cellular levels the impact of the Y861C substitution (p.Tyr861Cys) on NLRP3 activation. METHODS: Clinical features of 14 patients with CAPS and heterozygous substitution at position 861 in the LRR domain of NLRP3 were compared to clinical features of 48 patients with CAPS and pathogenic variants outside the LRR domain of NLRP3. IL-1ß secretion by PBMCs and purified monocytes from patients and healthy donors was evaluated following LPS and monosodium urate crystal stimulation. RESULTS: Patients with substitution at position 861 of NLRP3 demonstrated a higher prevalence of sensorineural hearing loss while being less prone to skin urticarial. In contrast to patients with classical CAPS, cells from patients with a pathogenic variant at position 861 required an activation signal to secrete IL-1ß but produced more IL-1ß during the early and late phase of secretion than cells from healthy donors. CONCLUSIONS: Pathogenic variants of Y861 of NLRP3 drive a boost-dependent oversecretion of IL-1ß associated with an atypical CAPS phenotype.

Phenotype and cytokine profile in a TRAPS Syndrome family with TNFRSF1A p.(Thr79Met): Association with sacro-iliitis.

OBJECTIVE: A comparative retrospective and analytic study was performed in 13 members of a family, affected or not by tumor necrosis factor TNF-α receptor-associated periodic syndrome (TRAPS), including one patient with sacro-illitis. METHODS: Clinical features and TNFRSF1A gene analysis were reported for each family member, symptomatic or asymptomatic. Biological features including CRP/SAA, IgD and ex vivo T lymphocytes and myeloid-derived cytokine profile (IL1-ß, IL-1α, IL-1ra, IL-4, IL-10, IL-17, IFN-γ, TNF-α, IL-6) were characterized for all family members. CRP and IgD only were compared with those of 13 axial SA patients with TNF-blockade indication. RESULTS: Symptomatic TRAPS patients presented p.(Thr79Met) variant and generally complained of abdominal pain. They displayed higher SAA/IgD levels and IL-6/IL-1RA/IL-10 production by PBMC compared to asymptomatic family members. IgD serum level was higher in symptomatic members compared to SA patients. The patient with sacro-iliitis displayed the highest cytokine production and IgD serum levels. CONCLUSION: This study describes clinical heterogeneity in a family examined for TRAPS syndrome and reports the first sacro-iliitis in a patient with pathogenic TNFRSF1A variant. Dysregulated PBMC-derived cytokine and Il-10/IgD dysregulation in the patient with sacro-iliitis raises the issue of sacro-iliitis pathophysiology.

AA amyloidosis complicating cryopyrin-associated periodic syndrome: a study of 86 cases including 23 French patients and systematic review.

OBJECTIVE: Cryopyrin-associated periodic syndrome (CAPS) is a rare but treatable inherited autoinflammatory condition including familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and chronic infantile neurologic cutaneous articular syndrome (CINCA). Our objective was to describe the main features of CAPS AA amyloidosis (AA-CAPS) associated and the efficacy of IL-1 inhibitors in this indication. METHODS: Retrospective study in France associated with a systematic literature review. RESULTS: Eighty-six patients were identified: 23 new French cases and 63 from the literature, with a median age at amyloidosis diagnosis of 39 years old. CAPS subtypes were MWS (n = 62), FCAS (n = 9), frontier forms between MWS and FCAS (n = 12) and between CINCA and MWS (n = 3). NLRP3 had been sequenced in 60 patients (70%) and the most frequent mutation was R260W (60%). Three AA-CAPS patients displayed somatic NLRP3 mutations. Death occurred in 35 patients (41%), none of whom having ever received IL-1 inhibitors. Twenty-eight patients (33%) received IL-1 inhibitors, with a >50% decrease in proteinuria in 89% of cases. CONCLUSION: AA amyloidosis can occur in nearly all CAPS subtypes. IL-1 inhibitors are effective, underlining the necessity of an early diagnosis of CAPS in order to start this treatment as soon as possible among AA-CAPS patients.

Mevalonate Kinase-Associated Diseases: Hunting for Phenotype-Genotype Correlation.

Mevalonate kinase-associated diseases (MKAD) are caused by pathogenic mutations in the mevalonate kinase gene (MVK) and encompass several phenotypically different rare and hereditary autoinflammatory conditions. The most serious is a recessive systemic metabolic disease called mevalonic aciduria, and the most recently recognized is disseminated superficial actinic porokeratosis, a dominant disease limited to the skin. To evaluate a possible correlation between genotypes and (1) the different MKAD clinical subtypes or (2) the occurrence of severe manifestations, data were reviewed for all patients with MVK variants described in the literature (N = 346), as well as those referred to our center (N = 51). The genotypes including p.(Val377Ile) (homozygous or compound heterozygous) were more frequent in mild systemic forms but were also sometimes encountered with severe disease. We confirmed that amyloidosis was more prevalent in patients compound heterozygous for p.(Ile268Thr) and p.(Val377Ile) than in others and revealed new associations. Patients homozygous for p.(Leu264Phe), p.(Ala334Thr) or compound heterozygous for p.(His20Pro) and p.(Ala334Thr) had increased risk of severe neurological or ocular symptoms. All patients homozygous for p.(Leu264Phe) had a cataract. The variants associated with porokeratosis were relatively specific and more frequently caused a frameshift than in patients with other clinical forms (26% vs. 6%). We provide practical recommendations focusing on phenotype-genotype correlation in MKAD that could be helpful for prophylactic management.

AA amyloidosis revealing mevalonate kinase deficiency: A report of 20 cases including two new French cases and a comprehensive review of literature.

INTRODUCTION: Mevalonate kinase deficiency (MKD) is a rare autosomal recessive autoinflammatory disease that can lead to an inflammatory A amyloidosis (AA). METHODS: To study the occurrence of AA in MKD patients we performed a systemic review of the literature and described two novel patients. RESULTS: Amyloidosis occurred in 20 MKD patients, renal impairment being always the revealing symptom of AA. Although an accurate prevalence estimation is not possible since exact MKD prevalence is unknown, AA seems rare in MKD (about 6% if we estimate MKD prevalence at 300 patients worldwide). MVK gene study, available in 18 out of the 20 patients, confirmed two pathogenic mutations in all tested individuals. The most frequent genotype was V377I/I268T (n = 9/18). Retrospective search of clinical signs of MKD established, in all patients carrying MVK pathogenic mutations, a disease onset within the first four years of life. Nephrotic syndrome (n = 15), end-stage renal failure (n = 5) or both (n = 8) pointed out kidney amyloidosis. The youngest patient with renal amyloidosis was a European four-year-old girl previously misdiagnosed with PFAPA syndrome. Five patients died of AA amyloidosis despite the use of a biotherapy for two of them; kidney transplant was performed in nine individuals. Colchicine was not effective in any patient. Anti-interleukin-1 anakinra (n = 8), anti TNF etanercept (n = 7) and anti-interleukin 6 tocilizumab (n = 5) treatments were partially effective. CONCLUSION: Inflammatory A amyloidosis, a rare complication of MKD, can cause death or necessitate kidney transplantation. Early diagnosis and cytokine blocking biotherapy using anti-IL1, anti-TNF or anti-IL6 agents are required to prevent terminal renal failure.

Observational Study of a French and Belgian Multicenter Cohort of 23 Patients Diagnosed in Adulthood With Mevalonate Kinase Deficiency.

The aim of this study was to describe the clinical and biological features of Mevalonate kinase deficiency (MKD) in patients diagnosed in adulthood. This is a French and Belgian observational retrospective study from 2000 to 2014. To constitute the cohort, we cross-check the genetic and biochemical databases. The clinical, enzymatic, and genetic data were gathered from medical records. Twenty-three patients were analyzed. The mean age at diagnosis was 40 years, with a mean age at onset of symptoms of 3 years. All symptomatic patients had fever. Febrile attacks were mostly associated with arthralgia (90.9%); lymphadenopathy, abdominal pain, and skin lesions (86.4%); pharyngitis (63.6%); cough (59.1%); diarrhea, and hepatosplenomegaly (50.0%). Seven patients had psychiatric symptoms (31.8%). One patient developed recurrent seizures. Three patients experienced renal involvement (13.6%). Two patients had angiomyolipoma (9.1%). All but one tested patients had elevated serum immunoglobulin (Ig) D level. Twenty-one patients had genetic diagnosis; most of them were compound heterozygote (76.2%). p.Val377Ile was the most prevalent mutation. Structural articular damages and systemic AA amyloidosis were the 2 most serious complications. More than 65% of patients displayed decrease in severity and frequency of attacks with increasing age, but only 35% achieved remission. MKD diagnosed in adulthood shared clinical and genetic features with classical pediatric disease. An elevated IgD concentration is a good marker for MKD in adults. Despite a decrease of severity and frequency of attacks with age, only one-third of patients achieved spontaneous remission.

Musculoskeletal symptoms in patients with cryopyrin-associated periodic syndromes: a large database study.

OBJECTIVE: To determine the type and frequency of musculoskeletal symptoms at onset and during followup of cryopyrin-associated periodic syndromes (CAPS). METHODS: We retrospectively recorded the articular and muscular symptoms of patients with CAPS followed up in French hospitals. Data were presented as frequencies or the median (range), and patient groups were compared using chi-square test, Fisher's exact test, and Mann-Whitney test. RESULTS: The study included 133 patients (33 children), 20 with familial cold autoinflammatory syndrome, 88 with Muckle-Wells syndrome, 22 with chronic infantile neurologic, cutaneous, articular syndrome, and 3 with unclassified CAPS. The median age was 35 years (range 0-78 years) at the time of the study, 1 year (range 0-41 years) at symptom onset, and 23 years (range 0-58 years) at diagnosis. The disease was sporadic in 17% of the patients. Cutaneous symptoms predominated at onset (77%), followed by articular symptoms (30%). The p.Thr348Met and p.Arg260Trp NLRP3 mutations were significantly associated with the presence and absence of articular symptoms at onset, respectively. During followup, 86% of the patients had musculoskeletal symptoms, 88% had arthralgia, and 58% had arthritis, but only 9% had joint destruction. Tendinopathies occurred in 21.5% of the patients, tender points in 16.5%, and myalgia in 33%. Only 3 patients had typical knee deformities. Radiographs were rarely obtained. Except for bone deformities, osteoarticular symptoms occurred at similar frequencies in the different CAPS phenotypes. CONCLUSION: Joint manifestations were frequent in all CAPS phenotypes. Bone deformities were rare. Musculoskeletal manifestations varied within given families but tended to worsen over time.

Neonatal Silver-Russell syndrome with maternal uniparental heterodisomy, trisomy 7 mosaicism, and dysplasia of the cerebellum.

OBJECTIVES: We report here the unusual association of Silver-Russell syndrome (SRS) and cerebellar dysplasia with trisomy 7 mosaicism and maternal uniparental disomy of chromosome 7 [UPD(7)m]. METHODS: Low-level trisomy 7 mosaicism was diagnosed prenatally on amniocytes, and UPD(7)m was confirmed after birth. RESULTS: Medical examination at birth showed dysmorphic facial features of SRS. Cytogenetic analysis on several tissues and cells confirmed mosaic trisomy 7. Unusual severe psychomotor retardation, hypotonia, and choreoathetoid movement were noted at 6 months. Brain magnetic resonance imaging showed both cerebellar hypoplasia and dysplasia. CONCLUSIONS: This unusual association of SRS and dysplasia of the cerebellum might be related to the presence of the trisomy 7 mosaicism on the cerebellum. Our observation strengthens the hypothesis that the phenotype observed in patients with SRS with UPD(7)m might also result from an undetected low level of trisomy 7 mosaicism that could best be revealed by performing cytogenetic investigations.

Severe early-onset colitis revealing mevalonate kinase deficiency.

Hyperimmunoglobulinemia D is the less severe form of mevalonate kinase deficiency (MKD) caused by recessive inherited mutation in the mevalonate kinase gene. Hyperimmunoglobulinemia D is characterized by febrile attacks, often associated with transient digestive manifestations, such as abdominal pain, diarrhea, and vomiting. Here we report for the first time 2 patients with MKD revealed by severe neonatal colitis. Both patients had chronic bloody diarrhea and failure to thrive; 1 patient since the age of 1 month and the other since the age of 12 days. Total parenteral nutrition was required. A marked elevation of acute phase reactants was present, and no evidence of infection was found. In patient 1, ileocolonoscopy revealed ulcerative colitis at the age of 5 months. Patient 2 suffered from enterocolitis and shock, associated with multiple bowel adhesions at age 5 weeks; the rectosigmoidoscopy showed aphtoid lesions of the sigmoid colon. Pathologic findings of colonic biopsies revealed a dense polymorph inflammatory infiltrate associated with deep ulcerations. Febrile attacks occurred 2 months after the onset of digestive symptoms in patient 1, and at onset of disease in patient 2. Genomic sequencing of the mevalonate kinase gene revealed compound heterozygous mutations in both patients. Anti-interleukin-1 agent produced long-term remission of all digestive features and laboratory parameters. This report emphasizes that MKD may be the cause of severe early-onset inflammatory colitis, and must be considered by physicians, even in the absence of fever, after ruling out infections. Anti-interleukin-1 therapy may result in a dramatic improvement of MKD-related inflammatory bowel disease.

Muckle-Wells syndrome and male hypofertility: a case series.

OBJECTIVES: Muckle-Wells syndrome (MWS) is a rare autoinflammatory disorder associated with NLRP3 gene mutations, which cause excessive caspase-1 activation and processing of interleukin (IL)-1ß and IL-18. Here we investigated whether MWS disease may be associated with impaired fertility in male patients. METHODS: Medical records of all male MWS patients with NLRP3 mutations followed in our tertiary center for inherited autoinflammatory diseases were reviewed retrospectively for data indicating fertility problems. RESULTS: Six of 9 patients were unable to have children despite regular sexual activity during at least 2 years; 3 succeeded in having children through in vitro fertilization. Infertility was the main reason for divorce in 1 patient. Spermiogram analyses were available in 8 of the 9 patients. Oligozoospermia was observed in 5 patients and azoospermia in 3 patients. In 2 patients, treatment with IL-1-targeting drugs for 6 and 12 months, respectively, had a moderate or no effect on spermatozoa counts. In 2 patients testosterone levels were low and testosterone treatment significantly increased spermatozoa counts in 1 of them. CONCLUSIONS: MWS may be associated with subfertility and infertility in male patients. Consequently, sexual health and fertility should be assessed systematically in adolescent and adult male patients. Additional studies are required to establish the frequency of subfertility in male MWS patients, to understand when subfertility occurs in the disease natural history, and, finally, to investigate whether early management with IL-1-targeting drugs, or testosterone treatment or early sperm cryo-conservation may help to allow procreation.

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.

Combined mutation and rearrangement screening by quantitative PCR high-resolution melting: is it relevant for hereditary recurrent Fever genes?

The recent identification of genes implicated in hereditary recurrent fevers has allowed their specific diagnosis. So far however, only punctual mutations have been identified and a significant number of patients remain with no genetic confirmation of their disease after routine molecular approaches such as sequencing. The possible involvement of sequence rearrangements in these patients has only been examined in familial Mediterranean fever and was found to be unlikely. To assess the existence of larger genetic alterations in 3 other concerned genes, MVK (Mevalonate kinase), NLRP3 (Nod like receptor family, pyrin domain containing 3) and TNFRSF1A (TNF receptor superfamily 1A), we adapted the qPCR-HRM method to study possible intragenic deletions and duplications. This single-tube approach, combining both qualitative (mutations) and quantitative (rearrangement) screening, has proven effective in Lynch syndrome diagnosis. Using this approach, we studied 113 unselected (prospective group) and 88 selected (retrospective group) patients and identified no intragenic rearrangements in the 3 genes. Only qualitative alterations were found with a sensitivity similar to that obtained using classical molecular techniques for screening punctual mutations. Our results support that deleterious copy number alterations in MVK, NLRP3 and TNFRSF1A are rare or absent from the mutational spectrum of hereditary recurrent fevers, and demonstrate that a routine combined method such as qPCR-HRM provides no further help in genetic diagnosis. However, quantitative approaches such as qPCR or SQF-PCR did prove to be quick and effective and could still be useful after non contributory punctual mutation screening in the presence of clinically evocative signs.

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.

Allogeneic bone marrow transplantation in mevalonic aciduria.

Mevalonic aciduria is a rare, inborn error of isoprene biosynthesis characterized by severe, periodic attacks of fever and inflammation, developmental delay, ataxia, and dysmorphic features. This autosomal recessive disease is caused by a mutation in the mevalonate kinase gene that severely reduces mevalonate kinase activity. A 3-year-old boy with mevalonic aciduria whose condition had failed to improve with antiinflammatory treatment underwent allogeneic bone marrow transplantation from an HLA-identical sister who was a heterozygous carrier of the mutant gene. We observed sustained remission of febrile attacks and inflammation during a 15-month follow-up period.

A variant Muckle-Wells syndrome with a novel mutation in CIAS1 gene responding to anakinra.

Muckle-Wells syndrome (MWS) is a subset of autoinflammatory diseases. It is characterized by recurrent inflammatory crises associated with fever, abdominal pain, persistent urticaria, arthralgia, sensorineural deafness, and possible development of multiorgan amyloid A protein (AA)-type amyloidosis. Mutations in the CIAS1 gene have been reported in MWS. Interleukin 1B (IL-1B) probably plays a major role in the pathophysiology of the disease, and IL-1B blockade may be therapeutic for this syndrome. We report here a Turkish child with MWS treated with anakinra. A novel mutation (I480F) was identified in exon 3 of the CIAS1 gene in this patient. The resolution of inflammatory symptoms, normalization of serological values, and improvement in hearing was noted with anakinra treatment.

Recovery from deafness in a patient with Muckle-Wells syndrome treated with anakinra.

Muckle-Wells syndrome (MWS) is a dominantly inherited autoinflammatory disease characterized by rashes, fever, arthralgia, sensorineural deafness, and the possible development of systemic AA amyloidosis. We used anakinra to treat a 22-year-old patient with MWS who had deafness and a high serum level of C-reactive protein (CRP). Following treatment with anakinra, the patient's CRP level normalized, and she recovered from deafness. The fact that this occurrence has never been previously reported strengthens the role of anakinra in MWS but also raises new questions about the physiopathology of such deafness.