POU3F3 variants cause developmental delay, behavioral problems, hypotonia and dysmorphic features. We investigated the phenotypic and genetic landscape, and genotype–phenotype correlations in ...individuals with POU3F3‐related disorders. We recruited unpublished individuals with POU3F3 variants through international collaborations and obtained updated clinical data on previously published individuals. Trio exome sequencing or single exome sequencing followed by segregation analysis were performed in the novel cohort. Functional effects of missense variants were investigated with 3D protein modeling. We included 28 individuals (5 previously published) from 26 families carrying POU3F3 variants; 23 de novo and one inherited from an affected parent. Median age at study inclusion was 7.4 years. All had developmental delay mainly affecting speech, behavioral difficulties, psychiatric comorbidities and dysmorphisms. Additional features included gastrointestinal comorbidities, hearing loss, ophthalmological anomalies, epilepsy, sleep disturbances and joint hypermobility. Autism, hearing and eye comorbidities, dysmorphisms were more common in individuals with truncating variants, whereas epilepsy was only associated with missense variants. In silico structural modeling predicted that all (likely) pathogenic variants destabilize the DNA‐binding region of POU3F3. Our study refined the phenotypic and genetic landscape of POU3F3‐related disorders, it reports the functional properties of the identified pathogenic variants, and delineates some genotype–phenotype correlations.
Clinicians should suspect POU3F3‐related disorder when a patient presents with developmental delay mainly affecting speech, psychiatric comorbidities and facial dysmorphisms. Additional features include gastrointestinal comorbidities, hearing loss, epilepsy, hypotonia, sleep disturbances, skeletal malformations and joint hypermobility.
Abstract
Background
Monogenic autoinflammatory diseases are caused by pathogenic variants in genes that regulate innate immune responses, and are characterized by sterile systemic inflammatory ...episodes. Since symptoms can overlap within this rapidly expanding disease category, accurate genetic diagnosis is of the utmost importance to initiate early inflammation-targeted treatment and prevent clinically significant or life-threatening complications. Initial recommendations for the genetic diagnosis of autoinflammatory diseases were limited to a gene-by-gene diagnosis strategy based on the Sanger method, and restricted to the 4 prototypic recurrent fevers (MEFV, MVK, TNFRSF1A, and NLRP3 genes). The development of best practices guidelines integrating critical recent discoveries has become essential.
Methods
The preparatory steps included 2 online surveys and pathogenicity annotation of newly recommended genes. The current guidelines were drafted by European Molecular Genetics Quality Network members, then discussed by a panel of experts of the International Society for Systemic Autoinflammatory Diseases during a consensus meeting.
Results
In these guidelines, we combine the diagnostic strength of next-generation sequencing and recommendations to 4 more recently identified genes (ADA2, NOD2, PSTPIP1, and TNFAIP3), nonclassical pathogenic genetic alterations, and atypical phenotypes. We present a referral-based decision tree for test scope and method (Sanger versus next-generation sequencing) and recommend on complementary explorations for mosaicism, copy-number variants, and gene dose. A genotype table based on the 5-category variant pathogenicity classification provides the clinical significance of prototypic genotypes per gene and disease.
Conclusions
These guidelines will orient and assist geneticists and health practitioners in providing up-to-date and appropriate diagnosis to their patients.
Individuals harboring pathogenic variants in
ARHGEF9
, encoding an essential submembrane protein for gamma-aminobutyric acid (GABA)–ergic synapses named collybistin, show intellectual disability ...(ID), facial dysmorphism, behavioral disorders, and epilepsy. Only few affected females carrying large chromosomal rearrangements involving
ARHGEF9
have been reported so far. Through next-generation sequencing (NGS)–based panels, we identified two single nucleotide variants (SNVs) in
ARHGEF9
in two females with neurodevelopmental features. Sanger sequencing revealed that these variants were de novo. The X-inactivation pattern in peripheral blood cells was random. We report the first affected females harboring de novo SNVs in
ARHGEF9
, expanding the genotypic and phenotypic spectrum of
ARHGEF9
-related neurodevelopmental disorder in females.
To describe the epilepsy phenotype in a large international cohort of patients with KBG syndrome and to study a possible genotype-phenotype correlation.
We collected data of patients with ANKRD11 ...variants by contacting University Medical Centers in the Netherlands, an international network of collaborating clinicians, and study groups who previously published about KBG syndrome. All patients with a likely pathogenic or pathogenic ANKRD11 variant were included in our patient cohort and categorized into an 'epilepsy group' or 'non-epilepsy group'. Additionally, we included previously reported patients with (likely) pathogenic ANKRD11 variants and epilepsy from the literature.
We included 75 patients with KBG syndrome of whom 26 had epilepsy. Those with epilepsy more often had moderate to severe intellectual disability (42.3% vs 9.1% , RR 4.6 (95% CI 1.7-13.1)). Seizure onset in patients with KBG syndrome occurred at a median age of four years (range 12 months - 20 years) and the majority had generalized onset seizures (57.7%)with tonic-clonic seizures being most common (23.1%). The epilepsy type was mostly classified as generalized (42.9%) or combined generalized and focal (42.9%), not fulfilling criteria of an electroclinical syndrome diagnosis. Half of the epilepsy patients (50.0%) were seizure free on anti-seizure medication (ASM) for at least one year at the time of last assessment, but 26.9% of patients had drug-resistant epilepsy (failure of ≥ 2 ASM). No genotype-phenotype correlation could be identified for the presence of epilepsy or epilepsy characteristics.
Epilepsy in KBG syndrome most often presents as a generalized or combined focal and generalized type. No distinctive epilepsy syndrome could be identified. Patients with KBG syndrome and epilepsy had a significant poorer neurodevelopmental outcome compared to those without epilepsy. Clinicians should consider KBG syndrome as a causal etiology of epilepsy and be aware of the poorer neurodevelopmental outcome in individuals with epilepsy.
Dutch genome diagnostic centers (GDC) use next-generation sequencing (NGS)-based diagnostic applications for the diagnosis of primary immunodeficiencies (PIDs). The interpretation of genetic variants ...in many PIDs is complicated because of the phenotypic and genetic heterogeneity. To analyze uniformity of variant filtering, interpretation, and reporting in NGS-based diagnostics for PID, an external quality assessment was performed. Four main Dutch GDCs participated in the quality assessment. Unannotated variant call format (VCF) files of two PID patient analyses per laboratory were distributed among the four GDCs, analyzed, and interpreted (eight analyses in total). Variants that would be reported to the clinician and/or advised for further investigation were compared between the centers. A survey measuring the experiences of clinical laboratory geneticists was part of the study. Analysis of samples with confirmed diagnoses showed that all centers reported at least the variants classified as likely pathogenic (LP) or pathogenic (P) variants in all samples, except for variants in two genes (PSTPIP1 and BTK). The absence of clinical information complicated correct classification of variants. In this external quality assessment, the final interpretation and conclusions of the genetic analyses were uniform among the four participating genetic centers. Clinical and immunological data provided by a medical specialist are required to be able to draw proper conclusions from genetic data.
Objective:To assess the effect of measles, mumps and rubella (MMR) vaccination on disease activity in children with juvenile idiopathic arthritis (JIA).Methods:A retrospective observational ...multicentre cohort study was performed in 314 patients with JIA, born between 1989 and 1996. Disease activity and medication use were compared during the period of 6 months before vaccination versus 6 months after vaccination. Disease activity was measured by joint counts, the Physician’s global assessment scale and erythrocyte sedimentation rate. Next, we compared disease activity in patients vaccinated between 8 and 9 years of age with the activity in patients who had not been vaccinated at this time (who received MMR between the ages of 9 and 10 years).Results:No increase in disease activity or medication use was seen in the 6 months after MMR vaccination (n = 207), including in patients using methotrexate (n = 49). No overt measles infections were noted. When disease activity in vaccinated patients (n = 108) was compared with activity in those not yet vaccinated (n = 86), there were no significant differences.Conclusions:The MMR booster vaccination does not seem to aggravate disease activity in JIA. This indicates that the most patients with JIA can be vaccinated safely with the MMR vaccine. A prospective study is recommended.
Objective
Autologous stem cell transplantation (ASCT) induces long‐term drug‐free disease remission in patients with juvenile idiopathic arthritis. This study was undertaken to further unravel the ...immunologic mechanisms underlying ASCT by using a mouse model of proteoglycan‐induced arthritis (PGIA).
Methods
For initiation of PGIA, BALB/c mice received 2 intraperitoneal injections of human PG in a synthetic adjuvant on days 0 and 21. Five weeks after the first immunization, the mice were exposed to total body irradiation (7.5 Gy) and received (un)manipulated bone marrow (BM) grafts from mice with PGIA. Clinical scores, T cell reconstitution, (antigen‐specific) T cell cytokine production, and intracellular cytokine expression were determined following autologous BM transplantation (ABMT).
Results
ABMT resulted in amelioration and stabilization of arthritis scores. BM grafts containing T cells and T cell–depleted grafts provided the same clinical benefit, with similar reductions in PG‐induced T cell proliferation and the number of PG‐specific autoantibodies. In vivo reexposure to PG did not exacerbate disease. Following ABMT, basal levels of disease‐associated proinflammatory cytokines (interferon‐γ IFNγ, interleukin‐17 IL‐17, and tumor necrosis factor α TNFα) were reduced. In addition, restimulation of T cells with PG induced a strong reduction in disease‐associated proinflammatory cytokine production. Finally, although the remaining host T cells displayed a proinflammatory phenotype following ABMT, IFNγ, IL‐17, and TNFα production by the newly reconstituted donor‐derived T cells was significantly lower.
Conclusion
Taken together, our data suggest that ABMT restores immune tolerance by renewal and modulation of the Teff cell compartment, leading to a strong reduction in proinflammatory (self antigen–specific) T cell cytokine production.
Marked by incomplete division of the embryonic forebrain, holoprosencephaly is one of the most common human developmental disorders. Despite decades of phenotype-driven research, 80-90% of ...aneuploidy-negative holoprosencephaly individuals with a probable genetic aetiology do not have a genetic diagnosis. Here we report holoprosencephaly associated with variants in the two X-linked cohesin complex genes, STAG2 and SMC1A, with loss-of-function variants in 10 individuals and a missense variant in one. Additionally, we report four individuals with variants in the cohesin complex genes that are not X-linked, SMC3 and RAD21. Using whole mount in situ hybridization, we show that STAG2 and SMC1A are expressed in the prosencephalic neural folds during primary neurulation in the mouse, consistent with forebrain morphogenesis and holoprosencephaly pathogenesis. Finally, we found that shRNA knockdown of STAG2 and SMC1A causes aberrant expression of HPE-associated genes ZIC2, GLI2, SMAD3 and FGFR1 in human neural stem cells. These findings show the cohesin complex as an important regulator of median forebrain development and X-linked inheritance patterns in holoprosencephaly.
Innate and adaptive immunity contribute to the pathogenesis of autoimmune arthritis by generating and maintaining inflammation, which leads to tissue damage. Current biological therapies target ...innate immunity, eminently by interfering with single pro-inflammatory cytokine pathways. This approach has shown excellent efficacy in a good proportion of patients with Rheumatoid Arthritis (RA), but is limited by cost and side effects. Adaptive immunity, particularly T cells with a regulatory function, plays a fundamental role in controlling inflammation in physiologic conditions. A growing body of evidence suggests that modulation of T cell function is impaired in autoimmunity. Restoration of such function could be of significant therapeutic value. We have recently demonstrated that epitope-specific therapy can restore modulation of T cell function in RA patients. Here, we tested the hypothesis that a combination of anti-cytokine and epitope-specific immunotherapy may facilitate the control of autoimmune inflammation by generating active T cell regulation. This novel combination of mucosal tolerization to a pathogenic T cell epitope and single low dose anti-TNFalpha was as therapeutically effective as full dose anti-TNFalpha treatment. Analysis of the underlying immunological mechanisms showed induction of T cell immune deviation.
Here we report inherited dysregulation of protein phosphatase activity as a cause of intellectual disability (ID). De novo missense mutations in 2 subunits of serine/threonine (Ser/Thr) protein ...phosphatase 2A (PP2A) were identified in 16 individuals with mild to severe ID, long-lasting hypotonia, epileptic susceptibility, frontal bossing, mild hypertelorism, and downslanting palpebral fissures. PP2A comprises catalytic (C), scaffolding (A), and regulatory (B) subunits that determine subcellular anchoring, substrate specificity, and physiological function. Ten patients had mutations within a highly conserved acidic loop of the PPP2R5D-encoded B56δ regulatory subunit, with the same E198K mutation present in 6 individuals. Five patients had mutations in the PPP2R1A-encoded scaffolding Aα subunit, with the same R182W mutation in 3 individuals. Some Aα cases presented with large ventricles, causing macrocephaly and hydrocephalus suspicion, and all cases exhibited partial or complete corpus callosum agenesis. Functional evaluation revealed that mutant A and B subunits were stable and uncoupled from phosphatase activity. Mutant B56δ was A and C binding-deficient, while mutant Aα subunits bound B56δ well but were unable to bind C or bound a catalytically impaired C, suggesting a dominant-negative effect where mutant subunits hinder dephosphorylation of B56δ-anchored substrates. Moreover, mutant subunit overexpression resulted in hyperphosphorylation of GSK3β, a B56δ-regulated substrate. This effect was in line with clinical observations, supporting a correlation between the ID degree and biochemical disturbance.
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