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1.
Artículo en Inglés | MEDLINE | ID: mdl-38617829

RESUMEN

Background: Spinocerebellar ataxia 21 (SCA21) is a rare neurological disorder caused by heterozygous variants in TMEM240. A growing, yet still limited number of reports suggested that hyperkinetic movements should be considered a defining component of the disease. Case Series: We describe two newly identified families harboring the recurrent pathogenic TMEM240 p.Pro170Leu variant. Both index patients and the mother of the first proband developed movement disorders, manifesting as myoclonic dystonia and action-induced dystonia without co-occurring ataxia in one case, and pancerebellar syndrome complicated by action-induced dystonia in the other. We reviewed the literature on TMEM240 variants linked to hyperkinetic disorders, comparing our cases to described phenotypes. Discussion: Adding to prior preliminary observations, our series highlights the relevance of hyperkinetic movements as clinically meaningful features of SCA21. TMEM240 mutation should be included in the differential diagnosis of myoclonic dystonia and ataxia-dystonia syndromes.


Asunto(s)
Distonía , Trastornos Distónicos , Mioclonía , Degeneraciones Espinocerebelosas , Humanos , Distonía/diagnóstico , Distonía/genética , Mioclonía/diagnóstico , Mioclonía/genética , Hipercinesia , Ataxia , Enfermedades Raras , Síndrome , Proteínas de la Membrana
2.
J Neurol ; 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38441608

RESUMEN

BACKGROUND: Heterozygous loss-of-function variants in CHD8 have been associated with a syndromic neurodevelopmental-disease spectrum, collectively referred to as CHD8-related neurodevelopmental disorders. Several different clinical manifestations, affecting neurodevelopmental and systemic domains, have been described, presenting with highly variable expressivity. Some expressions are well established and comprise autism spectrum disorders, psychomotor delay with cognitive impairment, postnatal overgrowth with macrocephaly, structural brain abnormalities, gastrointestinal disturbances, and behavioral and sleep-pattern problems. However, the complete phenotypic spectrum of CHD8-related disorders is still undefined. In 2021, our group described two singular female patients with CHD8-related neurodevelopmental disorder and striking dystonic manifestations, prompting the suggestion that dystonia should be considered a possible component of this condition. CASE SERIES PRESENTATION: We describe three additional unrelated female individuals, each carrying a different CHD8 frameshift variant and whose clinical presentations were primarily characterized by young-onset dystonia. Their dystonic manifestations were remarkably heterogeneous and ranged from focal, exercise-dependent, apparently isolated forms to generalized permanent phenotypes accompanied by spasticity and tremor. Neurocognitive impairment and autistic behaviors, typical of CHD8-related disorders, were virtually absent or at the mild end of the spectrum. CONCLUSIONS: This work validates our previous observation that dystonia is part of the phenotypic spectrum of CHD8-related neurodevelopmental disorders with potential female preponderance, raising new challenges and opportunities in the diagnosis and management of this condition. It also highlights the importance of in-depth neurologic phenotyping of patients carrying variants associated with neurodevelopmental disorders, as the connection between neurodevelopmental and movement disorders is proving closer than previously appreciated.

3.
Neuropediatrics ; 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38547905

RESUMEN

In patients with neurodevelopmental disorders (NDDs), exome sequencing (ES), the diagnostic gold standard, reveals an underlying monogenic condition in only approximately 40% of cases. We report the case of a female patient with profound NDD who died 30 years ago at the age of 3 years and for whom genome sequencing (GS) now identified a single-exon deletion in TBCK previously missed by ExomeDepth, the copy number variation (CNV) detection algorithm in ES.Deoxyribonucleic acid (DNA) was extracted from frozen muscle tissue of the index patient and the parents' blood. Genome data were analyzed for structural variants and single nucleotide variants (SUVs)/indels as part of the Bavarian Genomes consortium project.Biallelic variants in TBCK, which are linked to the autosomal recessive disorder TBCK syndrome, were detected in the affected individual: a novel frameshift variant and a deletion of exon 23, previously established as common but underrecognized pathogenic variant in individuals with TBCK syndrome. While in the foregoing ES analysis, calling algorithms for (SNVs)/indels were able to identify the frameshift variant, ExomeDepth failed to call the intragenic deletion.Our case illustrates the added value of GS for the detection of single-exon deletions for which calling from ES data remains challenging and confirms that the deletion of exon 23 in TBCK may be underdiagnosed in patients with NDDs. Furthermore, it shows the importance of "molecular or genetic autopsy" allowing genetic risk counseling for family members as well as the end of a diagnostic odyssey of 30 years.

5.
Nat Neurosci ; 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38528203

RESUMEN

The mammalian telencephalon contains distinct GABAergic projection neuron and interneuron types, originating in the germinal zone of the embryonic basal ganglia. How genetic information in the germinal zone determines cell types is unclear. Here we use a combination of in vivo CRISPR perturbation, lineage tracing and ChIP-sequencing analyses and show that the transcription factor MEIS2 favors the development of projection neurons by binding enhancer regions in projection-neuron-specific genes during mouse embryonic development. MEIS2 requires the presence of the homeodomain transcription factor DLX5 to direct its functional activity toward the appropriate binding sites. In interneuron precursors, the transcription factor LHX6 represses the MEIS2-DLX5-dependent activation of projection-neuron-specific enhancers. Mutations of Meis2 result in decreased activation of regulatory enhancers, affecting GABAergic differentiation. We propose a differential binding model where the binding of transcription factors at cis-regulatory elements determines differential gene expression programs regulating cell fate specification in the mouse ganglionic eminence.

6.
Am J Hum Genet ; 111(3): 594-613, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38423010

RESUMEN

The endosomal sorting complex required for transport (ESCRT) machinery is essential for membrane remodeling and autophagy and it comprises three multi-subunit complexes (ESCRT I-III). We report nine individuals from six families presenting with a spectrum of neurodevelopmental/neurodegenerative features caused by bi-allelic variants in SNF8 (GenBank: NM_007241.4), encoding the ESCRT-II subunit SNF8. The phenotypic spectrum included four individuals with severe developmental and epileptic encephalopathy, massive reduction of white matter, hypo-/aplasia of the corpus callosum, neurodevelopmental arrest, and early death. A second cohort shows a milder phenotype with intellectual disability, childhood-onset optic atrophy, or ataxia. All mildly affected individuals shared the same hypomorphic variant, c.304G>A (p.Val102Ile). In patient-derived fibroblasts, bi-allelic SNF8 variants cause loss of ESCRT-II subunits. Snf8 loss of function in zebrafish results in global developmental delay and altered embryo morphology, impaired optic nerve development, and reduced forebrain size. In vivo experiments corroborated the pathogenicity of the tested SNF8 variants and their variable impact on embryo development, validating the observed clinical heterogeneity. Taken together, we conclude that loss of ESCRT-II due to bi-allelic SNF8 variants is associated with a spectrum of neurodevelopmental/neurodegenerative phenotypes mediated likely via impairment of the autophagic flux.


Asunto(s)
Epilepsia Generalizada , Atrofia Óptica , Animales , Humanos , Niño , Pez Cebra/genética , Atrofia Óptica/genética , Fenotipo , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética
7.
EBioMedicine ; 101: 105007, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38354534

RESUMEN

BACKGROUND: The dicarbonyl compounds methylglyoxal (MG), glyoxal (GO) and 3-deoxyglucosone (3-DG) have been linked to various diseases. However, disease-independent phenotypic and genotypic association studies with phenome-wide and genome-wide reach, respectively, have not been provided. METHODS: MG, GO and 3-DG were measured by LC-MS in 1304 serum samples of two populations (KORA, n = 482; BiDirect, n = 822) and assessed for associations with genome-wide SNPs (GWAS) and with phenome-wide traits. Redundancy analysis (RDA) was used to identify major independent trait associations. FINDINGS: Mutual correlations of dicarbonyls were highly significant, being stronger between MG and GO (ρ = 0.6) than between 3-DG and MG or GO (ρ = 0.4). Significant phenotypic results included associations of all dicarbonyls with sex, waist-to-hip ratio, glomerular filtration rate (GFR), gamma-glutamyltransferase (GGT), and hypertension, of MG and GO with age and C-reactive protein, of GO and 3-DG with glucose and antidiabetics, of MG with contraceptives, of GO with ferritin, and of 3-DG with smoking. RDA revealed GFR, GGT and, in case of 3-DG, glucose as major contributors to dicarbonyl variance. GWAS did not identify genome-wide significant loci. SNPs previously associated with glyoxalase activity did not reach nominal significance. When multiple testing was restricted to the lead SNPs of GWASs on the traits selected by RDA, 3-DG was found to be associated (p = 2.3 × 10-5) with rs1741177, an eQTL of NF-κB inhibitor NFKBIA. INTERPRETATION: This large-scale, population-based study has identified numerous associations, with GFR and GGT being of pivotal importance, providing unbiased perspectives on dicarbonyls beyond the current state. FUNDING: Deutsche Forschungsgemeinschaft, Helmholtz Munich, German Centre for Cardiovascular Research (DZHK), German Federal Ministry of Research and Education (BMBF).


Asunto(s)
Estudio de Asociación del Genoma Completo , gamma-Glutamiltransferasa , Humanos , Tasa de Filtración Glomerular , Piruvaldehído/metabolismo , Glioxal/metabolismo , Glucosa , Polimorfismo de Nucleótido Simple
8.
Health Policy ; 142: 104992, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38368661

RESUMEN

BACKGROUND: Social prescribing connects patients with community resources to improve their health and well-being. It is gaining momentum globally due to its potential for addressing non-medical causes of illness while building on existing resources and enhancing overall health at a relatively low cost. The COVID-19 pandemic further underscored the need for policy interventions to address health-related social issues such as loneliness and isolation. AIM: This paper presents evidence of the conceptualisation and implementation of social prescribing schemes in twelve countries: Australia, Austria, Canada, England, Finland, Germany, Portugal, the Slovak Republic, Slovenia, the Netherlands, the United States and Wales. METHODS: Twelve countries were identified through the Health Systems and Policy Monitor (HSPM) network and the EuroHealthNet Partnership. Information was collected through a twelve open-ended question survey based on a conceptual model inspired by the WHO's Health System Framework. RESULTS: We found that social prescribing can take different forms, and the scale of implementation also varies significantly. Robust evidence on impact is scarce and highly context-specific, with some indications of cost-effectiveness and positive impact on well-being. CONCLUSIONS: This paper provides insights into social prescribing in various contexts and may guide countries interested in holistically tackling health-related social factors and strengthening community-based care. Policies can support a more seamless integration of social prescribing into existing care, improve collaboration among sectors and training programs for health and social care professionals.


Asunto(s)
COVID-19 , Pandemias , Humanos , Estados Unidos , Países Desarrollados , Apoyo Social , Inglaterra
9.
Sleep ; 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38314840

RESUMEN

Restless legs syndrome (RLS) is a neurological disorder characterized by uncomfortable or unpleasant sensations in the legs during rest periods. To relieve these sensations, patients move their legs, causing sleep disruption. While the pathogenesis of RLS has yet to be resolved, there is a strong genetic association to the MEIS1 gene. A missense variant in MEIS1 is enriched 7-fold in RLS patients compared to non-affected individuals. We generated a mouse line carrying this mutation (p.Arg272His/c.815G>A), referred to herein as Meis1R272H/R272H (Meis1 point mutation), to determine whether it would phenotypically resemble RLS. As women are more prone to RLS, driven partly by an increased risk of developing RLS during pregnancy, we focussed on female homozygous mice. We evaluated RLS-related outcomes, particularly sensorimotor behavior and sleep, in young and aged mice. Compared to non-carrier littermates, homozygous mice displayed very few differences. Significant hyperactivity occurred before the lights-on (rest) period in aged female mice, reflecting the age-dependent incidence of RLS. Sensory experiments involving tactile feedback (rotorod, wheel running, and hotplate) were only marginally different. Overall, RLS-like phenomena were not recapitulated except for the increased wake activity prior to rest. This is likely due to the focus on young mice. Nevertheless, the Meis1R272H mouse line is a potentially useful RLS model, carrying a clinically relevant variant and showing an age-dependent phenotype.

10.
Clin Epigenetics ; 16(1): 29, 2024 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-38365790

RESUMEN

BACKGROUND: Dietary intake of n-3 polyunsaturated fatty acids (PUFA) may have a protective effect on the development of cardiovascular diseases, diabetes, depression and cancer, while a high intake of n-6 PUFA was often reported to be associated with inflammation-related traits. The effect of PUFAs on health outcomes might be mediated by DNA methylation (DNAm). The aim of our study is to identify the impact of PUFA intake on DNAm in the Cooperative Health Research in the Region of Augsburg (KORA) FF4 cohort and the Leiden Longevity Study (LLS). RESULTS: DNA methylation levels were measured in whole blood from the population-based KORA FF4 study (N = 1354) and LLS (N = 448), using the Illumina MethylationEPIC BeadChip and Illumina HumanMethylation450 array, respectively. We assessed associations between DNAm and intake of eight and four PUFAs in KORA and LLS, respectively. Where possible, results were meta-analyzed. Below the Bonferroni correction threshold (p < 7.17 × 10-8), we identified two differentially methylated positions (DMPs) associated with PUFA intake in the KORA study. The DMP cg19937480, annotated to gene PRDX1, was positively associated with docosahexaenoic acid (DHA) in model 1 (beta: 2.00 × 10-5, 95%CI: 1.28 × 10-5-2.73 × 10-5, P value: 6.98 × 10-8), while cg05041783, annotated to gene MARK2, was positively associated with docosapentaenoic acid (DPA) in our fully adjusted model (beta: 9.80 × 10-5, 95%CI: 6.25 × 10-5-1.33 × 10-4, P value: 6.75 × 10-8). In the meta-analysis, we identified the CpG site (cg15951061), annotated to gene CDCA7L below Bonferroni correction (1.23 × 10-7) associated with eicosapentaenoic acid (EPA) intake in model 1 (beta: 2.00 × 10-5, 95% CI: 1.27 × 10-5-2.73 × 10-5, P value = 5.99 × 10-8) and we confirmed the association of cg19937480 with DHA in both models 1 and 2 (beta: 2.07 × 10-5, 95% CI: 1.31 × 10-5-2.83 × 10-5, P value = 1.00 × 10-7 and beta: 2.19 × 10-5, 95% CI: 1.41 × 10-5-2.97 × 10-5, P value = 5.91 × 10-8 respectively). CONCLUSIONS: Our study identified three CpG sites associated with PUFA intake. The mechanisms of these sites remain largely unexplored, highlighting the novelty of our findings. Further research is essential to understand the links between CpG site methylation and PUFA outcomes.


Asunto(s)
Epigenoma , Ácidos Grasos Omega-3 , Humanos , Metilación de ADN , Ácidos Grasos , Ácidos Docosahexaenoicos , Proteínas Represoras
11.
Nat Rev Neurol ; 20(2): 114-126, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38172289

RESUMEN

The ability to sequence entire exomes and genomes has revolutionized molecular testing in rare movement disorders, and genomic sequencing is becoming an integral part of routine diagnostic workflows for these heterogeneous conditions. However, interpretation of the extensive genomic variant information that is being generated presents substantial challenges. In this Perspective, we outline multidimensional strategies for genetic diagnosis in patients with rare movement disorders. We examine bioinformatics tools and computational metrics that have been developed to facilitate accurate prioritization of disease-causing variants. Additionally, we highlight community-driven data-sharing and case-matchmaking platforms, which are designed to foster the discovery of new genotype-phenotype relationships. Finally, we consider how multiomic data integration might optimize diagnostic success by combining genomic, epigenetic, transcriptomic and/or proteomic profiling to enable a more holistic evaluation of variant effects. Together, the approaches that we discuss offer pathways to the improved understanding of the genetic basis of rare movement disorders.


Asunto(s)
Trastornos del Movimiento , Proteómica , Humanos , Biología Computacional/métodos , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Enfermedades Raras , Trastornos del Movimiento/diagnóstico , Trastornos del Movimiento/genética
13.
J Neurol ; 271(4): 1937-1946, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38127101

RESUMEN

BACKGROUND: Neuromuscular disorders (NMDs) are heterogeneous conditions with a considerable fraction attributed to monogenic defects. Despite the advancements in genomic medicine, many patients remain without a diagnosis. Here, we investigate whether a comprehensive reassessment strategy improves the diagnostic outcomes. METHODS: We analyzed 263 patients with NMD phenotypes that underwent diagnostic exome or genome sequencing at our tertiary referral center between 2015 and 2023. We applied a comprehensive reassessment encompassing variant reclassification, re-phenotyping and NGS data reanalysis. Multivariable logistic regression was performed to identify predictive factors associated with a molecular diagnosis. RESULTS: Initially, a molecular diagnosis was identified in 53 cases (20%), while an additional 23 (9%) had findings of uncertain significance. Following comprehensive reassessment, the diagnostic yield increased to 23%, revealing 44 distinct monogenic etiologies. Reasons for newly obtained molecular diagnoses were variant reclassifications in 7 and NGS data reanalysis in 3 cases including one recently described disease-gene association (DNAJB4). Male sex reduced the odds of receiving a molecular diagnosis (OR 0.42; 95%CI 0.21-0.82), while a positive family history (OR 5.46; 95%CI 2.60-11.76) and a myopathy phenotype (OR 2.72; 95%CI 1.11-7.14) increased the likelihood. 7% were resolved through targeted genetic testing or classified as acquired etiologies. CONCLUSION: Our findings reinforce the use of NGS in NMDs of suspected monogenic origin. We show that a comprehensive reassessment enhances diagnostic accuracy. However, one needs to be aware that genetic diagnoses are often made with uncertainty and can even be downgraded based on new evidence.


Asunto(s)
Enfermedades Musculares , Enfermedades Neuromusculares , Adulto , Humanos , Masculino , Enfermedades Neuromusculares/diagnóstico , Enfermedades Musculares/genética , Pruebas Genéticas , Secuenciación de Nucleótidos de Alto Rendimiento , Fenotipo
15.
Genet Med ; 25(12): 100971, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37675773

RESUMEN

PURPOSE: ATP2B2 encodes the variant-constrained plasma-membrane calcium-transporting ATPase-2, expressed in sensory ear cells and specialized neurons. ATP2B2/Atp2b2 variants were previously linked to isolated hearing loss in patients and neurodevelopmental deficits with ataxia in mice. We aimed to establish the association between ATP2B2 and human neurological disorders. METHODS: Multinational case recruitment, scrutiny of trio-based genomics data, in silico analyses, and functional variant characterization were performed. RESULTS: We assembled 7 individuals harboring rare, predicted deleterious heterozygous ATP2B2 variants. The alleles comprised 5 missense substitutions that affected evolutionarily conserved sites and 2 frameshift variants in the penultimate exon. For 6 variants, a de novo status was confirmed. Unlike described patients with hearing loss, the individuals displayed a spectrum of neurological abnormalities, ranging from ataxia with dystonic features to complex neurodevelopmental manifestations with intellectual disability, autism, and seizures. Two cases with recurrent amino-acid variation showed distinctive overlap with cerebellar atrophy-associated ataxia and epilepsy. In cell-based studies, all variants caused significant alterations in cytosolic calcium handling with both loss- and gain-of-function effects. CONCLUSION: Presentations in our series recapitulate key phenotypic aspects of Atp2b2-mouse models and underline the importance of precise calcium regulation for neurodevelopment and cerebellar function. Our study documents a role for ATP2B2 variants in causing heterogeneous neurodevelopmental and movement-disorder syndromes.


Asunto(s)
Ataxia Cerebelosa , Distonía , Pérdida Auditiva , Discapacidad Intelectual , Trastornos del Neurodesarrollo , Animales , Humanos , Ratones , Síntomas Conductuales , Calcio , Ataxia Cerebelosa/genética , Distonía/genética , Discapacidad Intelectual/genética , Trastornos del Neurodesarrollo/genética , Fenotipo , ATPasas Transportadoras de Calcio de la Membrana Plasmática , Convulsiones/genética
16.
Stem Cell Res ; 72: 103197, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37689041

RESUMEN

Mitochondrial membrane Protein-Associated Neurodegeneration (MPAN) is a lethal neurodegenerative disorder caused by mutations in the human gene C19orf12. The molecular mechanisms underlying the disorder are still unclear, and no established therapy is available. Here, we describe the generation and characterization of two human induced pluripotent stem cell (iPSC) lines derived from skin fibroblasts of two MPAN patients carrying homozygous recessive mutations in C19orf12. These iPSC lines represent a useful resource for future investigations on the pathology of MPAN, as well as for the development of successful treatments.


Asunto(s)
Células Madre Pluripotentes Inducidas , Humanos , Proteínas Mitocondriales/genética , Mutación/genética , Proteínas de la Membrana/genética , Fibroblastos
17.
Health Policy ; 137: 104913, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37757534

RESUMEN

Oral health has received increased attention in health services research and policy. This study aims to assess oral health outcomes and public coverage of oral health services in Belgium, Denmark, Germany, the Netherlands, and Spain. Various indicators were used to compare oral health outcomes concerning the most common disorders by age group. Coverage of oral health services was analyzed according to the dimensions of the WHO Universal Coverage Cube. The results showed major differences in the coverage of services for the adult population: coverage was most comprehensive in Germany, followed by Belgium and Denmark. In Spain and the Netherlands, public coverage was limited. Except in Spain, coverage of oral health services for children was high, although with some differences between countries. Regarding oral health outcomes measured by the T-Health index, no country showed outstanding results across all age groups. While Denmark, the Netherlands, and Spain performed above average among 5- to 7-year-olds, Denmark and Germany performed above average among 12- to 14-year-olds, the Netherlands, Spain, and Belgium among 35- to 44-year-olds, and Belgium and the Netherlands among 65- to 74-year-olds. The selection of countries of this study was limited due to the availability and quality of oral health data demonstrating the urgent need for the European member states to establish corresponding databases.


Asunto(s)
Atención a la Salud , Salud Bucal , Niño , Adulto , Humanos , Bélgica , Países Bajos , Alemania
18.
Health Policy ; 136: 104878, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37611521

RESUMEN

We assessed challenges that the COVID-19 pandemic presented for mental health systems and the responses to these challenges in 14 countries in Europe and North America. Experts from each country filled out a structured questionnaire with closed- and open-ended questions between January and June 2021. We conducted thematic analysis to investigate the qualitative responses to open-ended questions, and we summarized the responses to closed-ended survey items on changes in telemental health policies and regulations. Findings revealed that many countries grappled with the rising demand for mental health services against a backdrop of mental health provider shortages and challenges responding to workforce stress and burnout. All countries in our sample implemented new policies or initiatives to strengthen mental health service delivery - with more than two-thirds investing to bolster their specialized mental health care sector. There was a universal shift to telehealth to deliver a larger portion of mental health services in all 14 countries, which was facilitated by changes in national regulations and policies; 11 of the 14 participating countries relaxed regulations and 10 of 14 countries made changes to reimbursement policies to facilitate telemental health care. These findings provide a first step to assess the long-term challenges and re-organizational effect of the COVID-19 pandemic on mental health systems in Europe and North America.


Asunto(s)
COVID-19 , Humanos , Salud Mental , Pandemias , Política de Salud , América del Norte/epidemiología
19.
medRxiv ; 2023 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-37398376

RESUMEN

Purpose: De novo variants in CUL3 (Cullin-3 ubiquitin ligase) have been strongly associated with neurodevelopmental disorders (NDDs), but no large case series have been reported so far. Here we aimed to collect sporadic cases carrying rare variants in CUL3, describe the genotype-phenotype correlation, and investigate the underlying pathogenic mechanism. Methods: Genetic data and detailed clinical records were collected via multi-center collaboration. Dysmorphic facial features were analyzed using GestaltMatcher. Variant effects on CUL3 protein stability were assessed using patient-derived T-cells. Results: We assembled a cohort of 35 individuals with heterozygous CUL3 variants presenting a syndromic NDD characterized by intellectual disability with or without autistic features. Of these, 33 have loss-of-function (LoF) and two have missense variants. CUL3 LoF variants in patients may affect protein stability leading to perturbations in protein homeostasis, as evidenced by decreased ubiquitin-protein conjugates in vitro . Specifically, we show that cyclin E1 (CCNE1) and 4E-BP1 (EIF4EBP1), two prominent substrates of CUL3, fail to be targeted for proteasomal degradation in patient-derived cells. Conclusion: Our study further refines the clinical and mutational spectrum of CUL3 -associated NDDs, expands the spectrum of cullin RING E3 ligase-associated neuropsychiatric disorders, and suggests haploinsufficiency via LoF variants is the predominant pathogenic mechanism.

20.
Mov Disord ; 38(10): 1914-1924, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37485550

RESUMEN

BACKGROUND: Protein synthesis is a tightly controlled process, involving a host of translation-initiation factors and microRNA-associated repressors. Variants in the translational regulator EIF2AK2 were first linked to neurodevelopmental-delay phenotypes, followed by their implication in dystonia. Recently, de novo variants in EIF4A2, encoding eukaryotic translation initiation factor 4A isoform 2 (eIF4A2), have been described in pediatric cases with developmental delay and intellectual disability. OBJECTIVE: We sought to characterize the role of EIF4A2 variants in dystonic conditions. METHODS: We undertook an unbiased search for likely deleterious variants in mutation-constrained genes among 1100 families studied with dystonia. Independent cohorts were screened for EIF4A2 variants. Western blotting and immunocytochemical studies were performed in patient-derived fibroblasts. RESULTS: We report the discovery of a novel heterozygous EIF4A2 frameshift deletion (c.896_897del) in seven patients from two unrelated families. The disease was characterized by adolescence- to adulthood-onset dystonia with tremor. In patient-derived fibroblasts, eIF4A2 production amounted to only 50% of the normal quantity. Reduction of eIF4A2 was associated with abnormally increased levels of IMP1, a target of Ccr4-Not, the complex that interacts with eIF4A2 to mediate microRNA-dependent translational repression. By complementing the analyses with fibroblasts bearing EIF4A2 biallelic mutations, we established a correlation between IMP1 expression alterations and eIF4A2 functional dosage. Moreover, eIF4A2 and Ccr4-Not displayed significantly diminished colocalization in dystonia patient cells. Review of international databases identified EIF4A2 deletion variants (c.470_472del, c.1144_1145del) in another two dystonia-affected pedigrees. CONCLUSIONS: Our findings demonstrate that EIF4A2 haploinsufficiency underlies a previously unrecognized dominant dystonia-tremor syndrome. The data imply that translational deregulation is more broadly linked to both early neurodevelopmental phenotypes and later-onset dystonic conditions. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Asunto(s)
Distonía , Trastornos Distónicos , MicroARNs , Trastornos del Movimiento , Adolescente , Niño , Humanos , Distonía/genética , Trastornos Distónicos/genética , Haploinsuficiencia/genética , MicroARNs/genética , Factores de Iniciación de Péptidos/genética , Biosíntesis de Proteínas/genética , Temblor
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