73 research outputs found
Erratum: Evaluation of DNA Methylation Episignatures for Diagnosis and Phenotype Correlations in 42 Mendelian Neurodevelopmental Disorders (The American Journal of Human Genetics (2020) 106(3) (356–370), (S0002929720300197), (10.1016/j.ajhg.2020.01.019))
(The American Journal of Human Genetics 106, 356–370; March 5, 2020) In the version of this paper originally published, the underlying cause for Hunter McAlpine syndrome was incorrectly described in Table 1. The relevant description has been changed to read “Chr5q35-qter duplication involving NSD1” in the updated Table 1 reflected here. The authors apologize for this error
Mutations in GABRB3
Objective: To examine the role of mutations in GABRB3 encoding the b3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. Methods: We performed massive parallel sequencing of GABRB3 in 416 patients with a range of epileptic encephalopathies and childhood-onset epilepsies and recruited additional patients with epilepsy with GABRB3 mutations from other research and diagnostic programs. Results: We identified 22 patients with heterozygous mutations in GABRB3, including 3 probands frommultiplex families. The phenotypic spectrum of the mutation carriers ranged from simple febrile seizures, genetic epilepsies with febrile seizures plus, and epilepsy withmyoclonic-atonic seizures to West syndrome and other types of severe, early-onset epileptic encephalopathies. Electrophysiologic analysis of 7 mutations in Xenopus laevis oocytes, using coexpression of wild-type or mutant beta(3), together with alpha(5) and gamma(2s) subunits and an automated 2-microelectrode voltage-clamp system, revealed reduced GABA-induced current amplitudes or GABA sensitivity for 5 of 7 mutations. Conclusions: Our results indicate that GABRB3 mutations are associated with a broad phenotypic spectrum of epilepsies and that reduced receptor function causing GABAergic disinhibition represents the relevant disease mechanism
NEXMIF encephalopathy:an X-linked disorder with male and female phenotypic patterns
Purpose Pathogenic variants in the X-linked gene NEXMIF (previously KIAA2022) are associated with intellectual disability (ID), autism spectrum disorder, and epilepsy. We aimed to delineate the female and male phenotypic spectrum of NEXMIF encephalopathy. Methods Through an international collaboration, we analyzed the phenotypes and genotypes of 87 patients with NEXMIF encephalopathy. Results Sixty-three females and 24 males (46 new patients) with NEXMIF encephalopathy were studied, with 30 novel variants. Phenotypic features included developmental delay/ID in 86/87 (99%), seizures in 71/86 (83%) and multiple comorbidities. Generalized seizures predominated including myoclonic seizures and absence seizures (both 46/70, 66%), absence with eyelid myoclonia (17/70, 24%), and atonic seizures (30/70, 43%). Males had more severe developmental impairment; females had epilepsy more frequently, and varied from unaffected to severely affected. All NEXMIF pathogenic variants led to a premature stop codon or were deleterious structural variants. Most arose de novo, although X-linked segregation occurred for both sexes. Somatic mosaicism occurred in two males and a family with suspected parental mosaicism. Conclusion NEXMIF encephalopathy is an X-linked, generalized developmental and epileptic encephalopathy characterized by myoclonic-atonic epilepsy overlapping with eyelid myoclonia with absence. Some patients have developmental encephalopathy without epilepsy. Males have more severe developmental impairment. NEXMIF encephalopathy arises due to loss-of-function variants
NEXMIF encephalopathy: an X-linked disorder with male and female phenotypic patterns
Purpose:
Pathogenic variants in the X-linked gene NEXMIF (previously KIAA2022) are associated with intellectual disability (ID), autism spectrum disorder, and epilepsy. We aimed to delineate the female and male phenotypic spectrum of NEXMIF encephalopathy.
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Methods:
Through an international collaboration, we analyzed the phenotypes and genotypes of 87 patients with NEXMIF encephalopathy.
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Results:
Sixty-three females and 24 males (46 new patients) with NEXMIF encephalopathy were studied, with 30 novel variants. Phenotypic features included developmental delay/ID in 86/87 (99%), seizures in 71/86 (83%) and multiple comorbidities. Generalized seizures predominated including myoclonic seizures and absence seizures (both 46/70, 66%), absence with eyelid myoclonia (17/70, 24%), and atonic seizures (30/70, 43%). Males had more severe developmental impairment; females had epilepsy more frequently, and varied from unaffected to severely affected. All NEXMIF pathogenic variants led to a premature stop codon or were deleterious structural variants. Most arose de novo, although X-linked segregation occurred for both sexes. Somatic mosaicism occurred in two males and a family with suspected parental mosaicism.
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Conclusion:
NEXMIF encephalopathy is an X-linked, generalized developmental and epileptic encephalopathy characterized by myoclonic–atonic epilepsy overlapping with eyelid myoclonia with absence. Some patients have developmental encephalopathy without epilepsy. Males have more severe developmental impairment. NEXMIF encephalopathy arises due to loss-of-function variants
Evaluation of DNA Methylation Episignatures for Diagnosis and Phenotype Correlations in 42 Mendelian Neurodevelopmental Disorders.
Genetic syndromes frequently present with overlapping clinical features and inconclusive or ambiguous genetic findings which can confound accurate diagnosis and clinical management. An expanding number of genetic syndromes have been shown to have unique genomic DNA methylation patterns (called episignatures ). Peripheral blood episignatures can be used for diagnostic testing as well as for the interpretation of ambiguous genetic test results. We present here an approach to episignature mapping in 42 genetic syndromes, which has allowed the identification of 34 robust disease-specific episignatures. We examine emerging patterns of overlap, as well as similarities and hierarchical relationships across these episignatures, to highlight their key features as they are related to genetic heterogeneity, dosage effect, unaffected carrier status, and incomplete penetrance. We demonstrate the necessity of multiclass modeling for accurate genetic variant classification and show how disease classification using a single episignature at a time can sometimes lead to classification errors in closely related episignatures. We demonstrate the utility of this tool in resolving ambiguous clinical cases and identification of previously undiagnosed cases through mass screening of a large cohort of subjects with developmental delays and congenital anomalies. This study more than doubles the number of published syndromes with DNA methylation episignatures and, most significantly, opens new avenues for accurate diagnosis and clinical assessment in individuals affected by these disorders
Phenotypic spectrum and transcriptomic profile associated with germline variants in TRAF7
PURPOSE: Somatic variants in tumor necrosis factor receptor-associated factor 7 (TRAF7) cause meningioma, while germline variants have recently been identified in seven patients with developmental delay and cardiac, facial, and digital anomalies. We aimed to define the clinical and mutational spectrum associated with TRAF7 germline variants in a large series of patients, and to determine the molecular effects of the variants through transcriptomic analysis of patient fibroblasts. METHODS: We performed exome, targeted capture, and Sanger sequencing of patients with undiagnosed developmental disorders, in multiple independent diagnostic or research centers. Phenotypic and mutational comparisons were facilitated through data exchange platforms. Whole-transcriptome sequencing was performed on RNA from patient- and control-derived fibroblasts. RESULTS: We identified heterozygous missense variants in TRAF7 as the cause of a developmental delay-malformation syndrome in 45 patients. Major features include a recognizable facial gestalt (characterized in particular by blepharophimosis), short neck, pectus carinatum, digital deviations, and patent ductus arteriosus. Almost all variants occur in the WD40 repeats and most are recurrent. Several differentially expressed genes were identified in patient fibroblasts. CONCLUSION: We provide the first large-scale analysis of the clinical and mutational spectrum associated with the TRAF7 developmental syndrome, and we shed light on its molecular etiology through transcriptome studies
Clinical spectrum of STX1B-related epileptic disorders
OBJECTIVE: The aim of this study was to expand the spectrum of epilepsy syndromes related to STX1B, encoding the presynaptic protein syntaxin-1B, and establish genotype-phenotype correlations by identifying further disease-related variants. METHODS: We used next-generation sequencing in the framework of research projects and diagnostic testing. Clinical data and EEGs were reviewed, including already published cases. To estimate the pathogenicity of the variants, we used established and newly developed in silico prediction tools. RESULTS: We describe 17 new variants in STX1B, which are distributed across the whole gene. We discerned 4 different phenotypic groups across the newly identified and previously published patients (49 patients in 23 families): (1) 6 sporadic patients or families (31 affected individuals) with febrile and afebrile seizures with a benign course, generally good drug response, normal development, and without permanent neurologic deficits; (2) 2 patients with genetic generalized epilepsy without febrile seizures and cognitive deficits; (3) 13 patients or families with intractable seizures, developmental regression after seizure onset and additional neuropsychiatric symptoms; (4) 2 patients with focal epilepsy. More often, we found loss-of-function mutations in benign syndromes, whereas missense variants in the SNARE motif of syntaxin-1B were associated with more severe phenotypes. CONCLUSION: These data expand the genetic and phenotypic spectrum of STX1B-related epilepsies to a diverse range of epilepsies that span the International League Against Epilepsy classification. Variants in STX1B are protean and contribute to many different epilepsy phenotypes, similar to SCN1A, the most important gene associated with fever-associated epilepsies
Clinical spectrum of STX1B-related epileptic disorders
Objective
The aim of this study was to expand the spectrum of epilepsy syndromes related to STX1B, encoding the presynaptic protein syntaxin- 1B, and establish genotype-phenotype correlations by identifying further disease related variants.
Methods
We used next-generation sequencing in the framework of research projects and diagnostic testing. Clinical data and EEGs were reviewed, including already published cases. To estimate the pathogenicity of the variants, we used established and newly developed in silico prediction tools.
Results
We describe 17 new variants in STX1B, which are distributed across the whole gene. We discerned 4 different phenotypic groups across the newly identified and previously published patients (49 patients in 23 families): (1) 6 sporadic patients or families (31 affected individuals) with febrile and afebrile seizures with a benign course, generally good drug response, normal development, and without permanent neurologic deficits; (2) 2 patients with genetic generalized epilepsy without febrile seizures and cognitive deficits; (3) 13 patients or families with intractable seizures, developmental regression after seizure onset and additional neuropsychiatric symptoms; (4) 2 patients with focal epilepsy. More often, we found loss-of-function mutations in benign syndromes, whereas missense variants in the SNARE motif of syntaxin-1B were associated with more severe phenotypes.
Conclusion
These data expand the genetic and phenotypic spectrum of STX1B-related epilepsies to a diverse range of epilepsies that span the International League Against Epilepsy classification. Variants in STX1B are protean and contribute to many different epilepsy phenotypes, similar to SCN1A, the most important gene associated with fever-associated epilepsies
Missense variants in ANKRD11 cause KBG syndrome by impairment of stability or transcriptional activity of the encoded protein
Purpose
Although haploinsufficiency of ANKRD11 is among the most common genetic causes of neurodevelopmental disorders, the role of rare ANKRD11 missense variation remains unclear. We characterized clinical, molecular, and functional spectra of ANKRD11 missense variants.
Methods
We collected clinical information of individuals with ANKRD11 missense variants and evaluated phenotypic fit to KBG syndrome. We assessed pathogenicity of variants through in silico analyses and cell-based experiments.
Results
We identified 20 unique, mostly de novo, ANKRD11 missense variants in 29 individuals, presenting with syndromic neurodevelopmental disorders similar to KBG syndrome caused by ANKRD11 protein truncating variants or 16q24.3 microdeletions. Missense variants significantly clustered in repression domain 2 at the ANKRD11 C-terminus. Of the 10 functionally studied missense variants, 6 reduced ANKRD11 stability. One variant caused decreased proteasome degradation and loss of ANKRD11 transcriptional activity.
Conclusion
Our study indicates that pathogenic heterozygous ANKRD11 missense variants cause the clinically recognizable KBG syndrome. Disrupted transrepression capacity and reduced protein stability each independently lead to ANKRD11 loss-of-function, consistent with haploinsufficiency. This highlights the diagnostic relevance of ANKRD11 missense variants, but also poses diagnostic challenges because the KBG-associated phenotype may be mild and inherited pathogenic ANKRD11 (missense) variants are increasingly observed, warranting stringent variant classification and careful phenotyping
Utilisation du REMDÉSIVIR et impact potentiel sur divers paramètres biologiques.
CONTEXTE: Le Remdésivir (R), antiviral inhibant l’ARN polymérase du SARS-CoV-2, a été utilisé dans le cadre d’une Autorisation temporaire d’utilisation (ATU), puis de l’Autorisation de mise sur le marché (AMM) pour les pneumopathies à COVID-19 modérées à sévères. OBJECTIFS: Les objectifs de ce travail sont de décrire la population ayant reçu le R et les variations biologiques possiblement associées à son administration. PATIENTS ET MÉTHODES: Une étude rétrospective monocentrique incluant les patients ayant reçu du R entre le 15/09 et le 15/12/2020 a été menée. Les caractéristiques des patients, les modalités de leur Prise en charge (PEC), leur devenir et les paramètres biologiques incluant créatinine, ASAT, ALAT, CRP et D-dimères ont été recueillis dans les 48 heures avant et après l’administration de R via Crossway®, ICCA® et Cyberlab®. Les données étaient exploitables (DE) quand les deux valeurs avant et après R étaient disponibles pour chaque paramètre. RÉSULTATS: Au total, 88 patients ont été inclus (âge médian = 70 ans, sexe-ratio = 2/1, moy indice masse corporelle = 30,19 ± 6,38 kg/m(2)). Une comorbidité était présente chez 94,3 % des patients : antécédent cardiovasculaire (76,1 %), obésité (48,9 %), diabète (30,7 %), antécédent pulmonaire (13,6 %) et immunodépression (6,8 %). Le R était initié dans 62,5 % des cas en réanimation et 37,5 % en médecine, en moyenne 7,9 ± 3,7 jours (j) [1 ; 19] (médiane = 8 jours) après le début des symptômes ; la durée moyenne de traitement était de 6,2 ± 2,2 jours [1 ; 10] (médiane = 5 j). R a été arrêté prématurément pour 7 patients : 2 bilans biologiques altérés, 2 transferts vers d’autres hôpitaux, 2 améliorations et un décès. La durée moyenne de séjour des patients sous R était de 12,5 ± 8,3 jours [4 ; 55] (médiane = 10 jours). Après sortie d’hospitalisation, 47,7 % sont rentrés à domicile, 27,3 % sont sortis en soins de suite et de réadaptation, 14,8 % sont décédés et 10,2 % des patients ont été transférés vers d’autres hôpitaux. Une diminution du débit de filtration glomérulaire (77,3 % de DE) était relevée chez 54,4 % des patients. Le passage d’un stade d’insuffisance rénale légère à sévère a été noté chez 3 patients (dont 2 dialysés à la fin du R). Après R, 18,8 % avaient des ALAT > normale (N) (54,5 % DE) et 17,0 % ASAT supérieure à la normale (N) (53,4 % DE) pour une concentration initialement N. Les valeurs maximales d’ASAT ont atteint 4 fois la N. La moyenne des CRP avant R était de 115,4 ± 82,5 mg/L (66 patients) versus 31,9 ± 45,0 mg/L après (39 patients). Les D-dimères avant R étaient de 1728,5 ± 2101 ng/mL pour 79 patients. Aucun effet indésirable n’a été rapporté. DISCUSSION/CONCLUSION: L’échantillon présente des caractéristiques statistiquement comparables aux données de la littérature (p > 0,05). Les bilans biologiques ont été moins réalisés après que le R ait obtenu l’AMM. Aussi, le manque de données exploitables n’a pas permis d’établir de corrélation statistique de l’utilisation du R à la variation des paramètres étudiés. La pathologie, les comorbidités et la PEC pourraient être des facteurs confondants. Il serait intéressant d’effectuer une étude multicentrique sur un large échantillon et d’inclure des données supplémentaires
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