RESUMO
In the TRIDENT-2 study, all pregnant women in the Netherlands are offered genome-wide non-invasive prenatal testing (GW-NIPT) with a choice of receiving either full screening or screening solely for common trisomies. Previous data showed that GW-NIPT can reliably detect common trisomies in the general obstetric population and that this test can also detect other chromosomal abnormalities (additional findings). However, evidence regarding the clinical impact of screening for additional findings is lacking. Therefore, we present follow-up results of the TRIDENT-2 study to determine this clinical impact based on the laboratory and perinatal outcomes of cases with additional findings. Between April 2017 and April 2019, additional findings were detected in 402/110,739 pregnancies (0.36%). For 358 cases, the origin was proven to be either fetal (n = 79; 22.1%), (assumed) confined placental mosaicism (CPM) (n = 189; 52.8%), or maternal (n = 90; 25.1%). For the remaining 44 (10.9%), the origin of the aberration could not be determined. Most fetal chromosomal aberrations were pathogenic and associated with severe clinical phenotypes (61/79; 77.2%). For CPM cases, occurrence of pre-eclampsia (8.5% [16/189] vs 0.5% [754/159,924]; RR 18.5), and birth weight <2.3rd percentile (13.6% [24/177] vs 2.5% [3,892/155,491]; RR 5.5) were significantly increased compared to the general obstetric population. Of the 90 maternal findings, 12 (13.3%) were malignancies and 32 (35.6%) (mosaic) pathogenic copy number variants, mostly associated with mild or no clinical phenotypes. Data from this large cohort study provide crucial information for deciding if and how to implement GW-NIPT in screening programs. Additionally, these data can inform the challenging interpretation, counseling, and follow-up of additional findings.
Assuntos
Diagnóstico Pré-Natal , Trissomia , Estudos de Coortes , Feminino , Seguimentos , Humanos , Mosaicismo , Placenta , Gravidez , Diagnóstico Pré-Natal/métodosRESUMO
Inherited glycosylphosphatidylinositol deficiency disorders (IGDs) are a group of rare multisystem disorders arising from pathogenic variants in glycosylphosphatidylinositol anchor pathway (GPI-AP) genes. Despite associating 24 of at least 31 GPI-AP genes with human neurogenetic disease, prior reports are limited to single genes without consideration of the GPI-AP as a whole and with limited natural history data. In this multinational retrospective observational study, we systematically analyse the molecular spectrum, phenotypic characteristics and natural history of 83 individuals from 75 unique families with IGDs, including 70 newly reported individuals; the largest single cohort to date. Core clinical features were developmental delay or intellectual disability (DD/ID, 90%), seizures (83%), hypotonia (72%) and motor symptoms (64%). Prognostic and biologically significant neuroimaging features included cerebral atrophy (75%), cerebellar atrophy (60%), callosal anomalies (57%) and symmetric restricted diffusion of the central tegmental tracts (60%). Sixty-one individuals had multisystem involvement including gastrointestinal (66%), cardiac (19%) and renal (14%) anomalies. Though dysmorphic features were appreciated in 82%, no single dysmorphic feature had a prevalence >30%, indicating substantial phenotypic heterogeneity. Follow-up data were available for all individuals, 15 of whom were deceased at the time of writing. Median age at seizure onset was 6 months. Individuals with variants in synthesis stage genes of the GPI-AP exhibited a significantly shorter time to seizure onset than individuals with variants in transamidase and remodelling stage genes of the GPI-AP (P = 0.046). Forty individuals had intractable epilepsy. The majority of individuals experienced delayed or absent speech (95%), motor delay with non-ambulance (64%), and severe-to-profound DD/ID (59%). Individuals with a developmental epileptic encephalopathy (51%) were at greater risk of intractable epilepsy (P = 0.003), non-ambulance (P = 0.035), ongoing enteral feeds (P < 0.001) and cortical visual impairment (P = 0.007). Serial neuroimaging showed progressive cerebral volume loss in 87.5% and progressive cerebellar atrophy in 70.8%, indicating a neurodegenerative process. Genetic analyses identified 93 unique variants (106 total), including 22 novel variants. Exploratory analyses of genotype-phenotype correlations using unsupervised hierarchical clustering identified novel genotypic predictors of clinical phenotype and long-term outcome with meaningful implications for management. In summary, we expand both the mild and severe phenotypic extremities of the IGDs, provide insights into their neurological basis, and vitally, enable meaningful genetic counselling for affected individuals and their families.
Assuntos
Glicosilfosfatidilinositóis , Humanos , Masculino , Feminino , Pré-Escolar , Criança , Adolescente , Estudos Retrospectivos , Lactente , Adulto , Glicosilfosfatidilinositóis/deficiência , Glicosilfosfatidilinositóis/genética , Deficiência Intelectual/genética , Deficiências do Desenvolvimento/genética , Adulto Jovem , Defeitos Congênitos da Glicosilação/genética , Fenótipo , Convulsões/genéticaRESUMO
The introduction of rapid exome sequencing (rES) for critically ill neonates admitted to the neonatal intensive care unit has made it possible to impact clinical decision-making. Unbiased prospective studies to quantify the impact of rES over routine genetic testing are, however, scarce. We performed a clinical utility study to compare rES to conventional genetic diagnostic workup for critically ill neonates with suspected genetic disorders. In a multicenter prospective parallel cohort study involving five Dutch NICUs, we performed rES in parallel to routine genetic testing for 60 neonates with a suspected genetic disorder and monitored diagnostic yield and the time to diagnosis. To assess the economic impact of rES, healthcare resource use was collected for all neonates. rES detected more conclusive genetic diagnoses than routine genetic testing (20% vs. 10%, respectively), in a significantly shorter time to diagnosis (15 days (95% CI 10-20) vs. 59 days (95% CI 23-98, p < 0.001)). Moreover, rES reduced genetic diagnostic costs by 1.5% (85 per neonate). CONCLUSION: Our findings demonstrate the clinical utility of rES for critically ill neonates based on increased diagnostic yield, shorter time to diagnosis, and net healthcare savings. Our observations warrant the widespread implementation of rES as first-tier genetic test in critically ill neonates with disorders of suspected genetic origin. WHAT IS KNOWN: ⢠Rapid exome sequencing (rES) enables diagnosing rare genetic disorders in a fast and reliable manner, but retrospective studies with neonates admitted to the neonatal intensive care unit (NICU) indicated that genetic disorders are likely underdiagnosed as rES is not routinely used. ⢠Scenario modeling for implementation of rES for neonates with presumed genetic disorders indicated an expected increase in costs associated with genetic testing. WHAT IS NEW: ⢠This unique prospective national clinical utility study of rES in a NICU setting shows that rES obtained more and faster diagnoses than conventional genetic tests. ⢠Implementation of rES as replacement for all other genetic tests does not increase healthcare costs but in fact leads to a reduction in healthcare costs.
Assuntos
Estado Terminal , Testes Genéticos , Recém-Nascido , Humanos , Sequenciamento do Exoma , Estudos Prospectivos , Estudos Retrospectivos , Países Baixos , Estudos de Coortes , Testes Genéticos/métodosRESUMO
Couples at risk of transmitting a genetic disease to their offspring may experience doubts about their reproductive options. This study examines the effects of an online decision aid (DA) on the (joint) reproductive decision-making process of couples (not pregnant at time of inclusion) at risk of transmitting a genetic disease to their offspring. The primary outcome is decisional conflict, and secondary outcomes are knowledge, realistic expectations, deliberation, joint informed decision-making, and decisional self-efficacy. These outcomes were measured with a pretest-posttest design: before use (T0), after use (T1), and 2 weeks after use (T2) of the decision aid (DA). Usability of the DA was assessed at T1. Paired sample t-tests were used to compute differences between baseline and subsequent measurements. The comparisons of T0-T1 and T0-T2 indicate a significant reduction in mean decisional conflict scores with stronger effects for participants with high baseline decisional conflict scores. Furthermore, use of the DA led to increased knowledge, improved realistic expectations, and increased levels of deliberation, with higher increase in participants with low baseline scores. Decision self-efficacy only improved for participants with lower baseline scores. Participants indicated that the information in the DA was comprehensible and clearly organized. These first results indicate that this online DA is an appropriate tool to support couples at risk of transmitting a genetic disease and a desire to have (a) child(ren) in their reproductive decision-making process.
Assuntos
Tomada de Decisões , Técnicas de Apoio para a Decisão , Criança , Humanos , Gravidez , Feminino , Projetos Piloto , Reprodução , EmoçõesRESUMO
TATA-binding protein associated factor 4 (TAF4) is a subunit of the Transcription Factor IID (TFIID) complex, a central player in transcription initiation. Other members of this multimeric complex have been implicated previously as monogenic disease genes in human developmental disorders. TAF4 has not been described to date as a monogenic disease gene. We here present a cohort of eight individuals, each carrying de novo putative loss-of-function (pLoF) variants in TAF4 and expressing phenotypes consistent with a neuro-developmental disorder (NDD). Common features include intellectual disability, abnormal behavior, and facial dysmorphisms. We propose TAF4 as a novel dominant disease gene for NDD, and coin this novel disorder "TAF4-related NDD" (T4NDD). We place T4NDD in the context of other disorders related to TFIID subunits, revealing shared features of T4NDD with other TAF-opathies.
Assuntos
Transtornos do Neurodesenvolvimento , Fatores Associados à Proteína de Ligação a TATA , Fator de Transcrição TFIID , Criança , Humanos , Deficiências do Desenvolvimento/genética , Transtornos do Neurodesenvolvimento/diagnóstico , Transtornos do Neurodesenvolvimento/genética , Fenótipo , Fatores Associados à Proteína de Ligação a TATA/genética , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Fator de Transcrição TFIID/genética , Fator de Transcrição TFIID/metabolismoRESUMO
The Netherlands launched a nationwide implementation study on non-invasive prenatal testing (NIPT) as a first-tier test offered to all pregnant women. This started on April 1, 2017 as the TRIDENT-2 study, licensed by the Dutch Ministry of Health. In the first year, NIPT was performed in 73,239 pregnancies (42% of all pregnancies), 7,239 (4%) chose first-trimester combined testing, and 54% did not participate. The number of trisomies 21 (239, 0.33%), 18 (49, 0.07%), and 13 (55, 0.08%) found in this study is comparable to earlier studies, but the Positive Predictive Values (PPV)-96% for trisomy 21, 98% for trisomy 18, and 53% for trisomy 13-were higher than expected. Findings other than trisomy 21, 18, or 13 were reported on request of the pregnant women; 78% of women chose to have these reported. The number of additional findings was 207 (0.36%); these included other trisomies (101, 0.18%, PPV 6%, many of the remaining 94% of cases are likely confined placental mosaics and possibly clinically significant), structural chromosomal aberrations (95, 0.16%, PPV 32%,) and complex abnormal profiles indicative of maternal malignancies (11, 0.02%, PPV 64%). The implementation of genome-wide NIPT is under debate because the benefits of detecting other fetal chromosomal aberrations must be balanced against the risks of discordant positives, parental anxiety, and a potential increase in (invasive) diagnostic procedures. Our first-year data, including clinical data and laboratory follow-up data, will fuel this debate. Furthermore, we describe how NIPT can successfully be embedded into a national screening program with a single chain for prenatal care including counseling, testing, and follow-up.
Assuntos
Síndrome de Down/diagnóstico , Testes Genéticos/métodos , Genoma Humano , Implementação de Plano de Saúde , Diagnóstico Pré-Natal/métodos , Síndrome da Trissomia do Cromossomo 13/diagnóstico , Síndrome da Trissomía do Cromossomo 18/diagnóstico , Adolescente , Adulto , Aberrações Cromossômicas , Síndrome de Down/epidemiologia , Síndrome de Down/genética , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Gravidez , Primeiro Trimestre da Gravidez , Prognóstico , Síndrome da Trissomia do Cromossomo 13/epidemiologia , Síndrome da Trissomia do Cromossomo 13/genética , Síndrome da Trissomía do Cromossomo 18/epidemiologia , Síndrome da Trissomía do Cromossomo 18/genética , Adulto JovemRESUMO
INTRODUCTION: Pigmentary mosaicism (PM) manifests by pigmentation anomalies along Blaschko's lines and represents a clue toward the molecular diagnosis of syndromic intellectual disability (ID). Together with new insights on the role for lysosomal signalling in embryonic stem cell differentiation, mutations in the X-linked transcription factor 3 (TFE3) have recently been reported in five patients. Functional analysis suggested these mutations to result in ectopic nuclear gain of functions. MATERIALS AND METHODS: Subsequent data sharing allowed the clustering of de novo TFE3 variants identified by exome sequencing on DNA extracted from leucocytes in patients referred for syndromic ID with or without PM. RESULTS: We describe the detailed clinical and molecular data of 17 individuals harbouring a de novo TFE3 variant, including the patients that initially allowed reporting TFE3 as a new disease-causing gene. The 12 females and 5 males presented with pigmentation anomalies on Blaschko's lines, severe ID, epilepsy, storage disorder-like features, growth retardation and recognisable facial dysmorphism. The variant was at a mosaic state in at least two male patients. All variants were missense except one splice variant. Eleven of the 13 variants were localised in exon 4, 2 in exon 3, and 3 were recurrent variants. CONCLUSION: This series further delineates the specific storage disorder-like phenotype with PM ascribed to de novo TFE3 mutation in exons 3 and 4. It confirms the identification of a novel X-linked human condition associated with mosaicism and dysregulation within the mechanistic target of rapamycin (mTOR) pathway, as well as a link between lysosomal signalling and human development.
Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Epilepsia/genética , Deficiência Intelectual/genética , Transtornos da Pigmentação/genética , Adolescente , Adulto , Criança , Pré-Escolar , Epilepsia/complicações , Epilepsia/patologia , Feminino , Genes Ligados ao Cromossomo X/genética , Humanos , Lactente , Deficiência Intelectual/complicações , Deficiência Intelectual/patologia , Masculino , Mosaicismo , Patologia Molecular/normas , Transtornos da Pigmentação/complicações , Transtornos da Pigmentação/patologia , Sequenciamento do Exoma , Adulto JovemRESUMO
The ubiquitin-proteasome system is the principal system for protein degradation mediated by ubiquitination and is involved in various cellular processes. Cullin-RING ligases (CRL) are one class of E3 ubiquitin ligases that mediate polyubiquitination of specific target proteins, leading to decomposition of the substrate. Cullin 3 (CUL3) is a member of the Cullin family proteins, which act as scaffolds of CRL. Here we describe three cases of global developmental delays, with or without epilepsy, who had de novo CUL3 variants. One missense variant c.854T>C, p.(Val285Ala) and two frameshift variants c.137delG, p.(Arg46Leufs*32) and c.1239del, p.(Asp413Glufs*42) were identified by whole-exome sequencing. The Val285 residue located in the Cullin N-terminal domain and p.Val285Ala CUL3 mutant showed significantly weaker interactions to the BTB domain proteins than wild-type CUL3. Our findings suggest that de novo CUL3 variants may cause structural instability of the CRL complex and impairment of the ubiquitin-proteasome system, leading to diverse neuropsychiatric disorders.
Assuntos
Proteínas Culina/genética , Proteínas Culina/metabolismo , Deficiências do Desenvolvimento/genética , Predisposição Genética para Doença , Espasmos Infantis/genética , Criança , Pré-Escolar , Deficiências do Desenvolvimento/complicações , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Mutação da Fase de Leitura , Células HEK293 , Humanos , Lactente , Masculino , Mutação de Sentido Incorreto , Ligação Proteica , Espasmos Infantis/complicações , Ubiquitina-Proteína Ligases/metabolismo , Sequenciamento do ExomaRESUMO
CDC42BPB encodes MRCKß (myotonic dystrophy-related Cdc42-binding kinase beta), a serine/threonine protein kinase, and a downstream effector of CDC42, which has recently been associated with Takenouchi-Kosaki syndrome, an autosomal dominant neurodevelopmental disorder. We identified 12 heterozygous predicted deleterious variants in CDC42BPB (9 missense, 2 frameshift, and 1 nonsense) in 14 unrelated individuals (confirmed de novo in 11/14) with neurodevelopmental disorders including developmental delay/intellectual disability, autism, hypotonia, and structural brain abnormalities including cerebellar vermis hypoplasia and agenesis/hypoplasia of the corpus callosum. The frameshift and nonsense variants in CDC42BPB are expected to be gene-disrupting and lead to haploinsufficiency via nonsense-mediated decay. All missense variants are located in highly conserved and functionally important protein domains/regions: 3 are found in the protein kinase domain, 2 are in the citron homology domain, and 4 in a 20-amino acid sequence between 2 coiled-coil regions, 2 of which are recurrent. Future studies will help to delineate the natural history and to elucidate the underlying biological mechanisms of the missense variants leading to the neurodevelopmental and behavioral phenotypes.
Assuntos
Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Miotonina Proteína Quinase/genética , Transtornos do Neurodesenvolvimento/genética , Adolescente , Adulto , Sequência de Aminoácidos , Transtorno Autístico/epidemiologia , Transtorno Autístico/genética , Transtorno Autístico/patologia , Criança , Pré-Escolar , Deficiências do Desenvolvimento/epidemiologia , Deficiências do Desenvolvimento/patologia , Feminino , Mutação da Fase de Leitura , Haploinsuficiência , Heterozigoto , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/epidemiologia , Deficiência Intelectual/patologia , Mutação com Perda de Função/genética , Masculino , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/epidemiologia , Transtornos do Neurodesenvolvimento/patologia , FenótipoRESUMO
OBJECTIVE: The purpose of this study was to explore the diagnostic yield and clinical utility of trio-based rapid whole exome sequencing (rWES) in pregnancies of fetuses with a wide range of congenital anomalies detected by ultrasound imaging. METHODS: In this observational study, we analyzed the first 54 cases referred to our laboratory for prenatal rWES to support clinical decision making, after the sonographic detection of fetal congenital anomalies. The most common identified congenital anomalies were skeletal dysplasia (n = 20), multiple major fetal congenital anomalies (n = 17) and intracerebral structural anomalies (n = 7). RESULTS: A conclusive diagnosis was identified in 18 of the 54 cases (33%). Pathogenic variants were detected most often in fetuses with skeletal dysplasia (n = 11) followed by fetuses with multiple major fetal congenital anomalies (n = 4) and intracerebral structural anomalies (n = 3). A survey, completed by the physicians for 37 of 54 cases, indicated that the rWES results impacted clinical decision making in 68% of cases. CONCLUSIONS: These results suggest that rWES improves prenatal diagnosis of fetuses with congenital anomalies, and has an important impact on prenatal and peripartum parental and clinical decision making.
Assuntos
Anormalidades Congênitas/diagnóstico , Anormalidades Congênitas/genética , Sequenciamento do Exoma , Ultrassonografia Pré-Natal , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Adulto , Tomada de Decisões , Feminino , Feto/diagnóstico por imagem , Testes Genéticos/métodos , Humanos , Masculino , Gravidez , Diagnóstico Pré-Natal/métodos , Reprodutibilidade dos Testes , Adulto JovemRESUMO
BACKGROUND & AIMS: Congenital diarrheal disorders are rare inherited intestinal disorders characterized by intractable, sometimes life-threatening, diarrhea and nutrient malabsorption; some have been associated with mutations in diacylglycerol-acyltransferase 1 (DGAT1), which catalyzes formation of triacylglycerol from diacylglycerol and acyl-CoA. We investigated the mechanisms by which DGAT1 deficiency contributes to intestinal failure using patient-derived organoids. METHODS: We collected blood samples from 10 patients, from 6 unrelated pedigrees, who presented with early-onset severe diarrhea and/or vomiting, hypoalbuminemia, and/or (fatal) protein-losing enteropathy with intestinal failure; we performed next-generation sequencing analysis of DNA from 8 patients. Organoids were generated from duodenal biopsies from 3 patients and 3 healthy individuals (controls). Caco-2 cells and patient-derived dermal fibroblasts were transfected or transduced with vectors that express full-length or mutant forms of DGAT1 or full-length DGAT2. We performed CRISPR/Cas9-guided disruption of DGAT1 in control intestinal organoids. Cells and organoids were analyzed by immunoblot, immunofluorescence, flow cytometry, chromatography, quantitative real-time polymerase chain reaction, and for the activity of caspases 3 and 7. RESULTS: In the 10 patients, we identified 5 bi-allelic loss-of-function mutations in DGAT1. In patient-derived fibroblasts and organoids, the mutations reduced expression of DGAT1 protein and altered triacylglycerol metabolism, resulting in decreased lipid droplet formation after oleic acid addition. Expression of full-length DGAT2 in patient-derived fibroblasts restored formation of lipid droplets. Organoids derived from patients with DGAT1 mutations were more susceptible to lipid-induced cell death than control organoids. CONCLUSIONS: We identified a large cohort of patients with congenital diarrheal disorders with mutations in DGAT1 that reduced expression of its product; dermal fibroblasts and intestinal organoids derived from these patients had altered lipid metabolism and were susceptible to lipid-induced cell death. Expression of full-length wildtype DGAT1 or DGAT2 restored normal lipid metabolism in these cells. These findings indicate the importance of DGAT1 in fat metabolism and lipotoxicity in the intestinal epithelium. A fat-free diet might serve as the first line of therapy for patients with reduced DGAT1 expression. It is important to identify genetic variants associated with congenital diarrheal disorders for proper diagnosis and selection of treatment strategies.
Assuntos
Diacilglicerol O-Aciltransferase/genética , Duodeno/metabolismo , Fibroblastos/metabolismo , Hipoalbuminemia/genética , Transtornos do Metabolismo dos Lipídeos/genética , Organoides/metabolismo , Enteropatias Perdedoras de Proteínas/genética , Células CACO-2 , Estudos de Casos e Controles , Caspase 3/metabolismo , Caspase 7/metabolismo , Criança , Pré-Escolar , Consanguinidade , Derme/citologia , Diacilglicerol O-Aciltransferase/deficiência , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Países Baixos , Forbóis , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , TurquiaRESUMO
PURPOSE: Haploinsufficiency of USP7, located at chromosome 16p13.2, has recently been reported in seven individuals with neurodevelopmental phenotypes, including developmental delay/intellectual disability (DD/ID), autism spectrum disorder (ASD), seizures, and hypogonadism. Further, USP7 was identified to critically incorporate into the MAGEL2-USP7-TRIM27 (MUST), such that pathogenic variants in USP7 lead to altered endosomal F-actin polymerization and dysregulated protein recycling. METHODS: We report 16 newly identified individuals with heterozygous USP7 variants, identified by genome or exome sequencing or by chromosome microarray analysis. Clinical features were evaluated by review of medical records. Additional clinical information was obtained on the seven previously reported individuals to fully elucidate the phenotypic expression associated with USP7 haploinsufficiency. RESULTS: The clinical manifestations of these 23 individuals suggest a syndrome characterized by DD/ID, hypotonia, eye anomalies,feeding difficulties, GERD, behavioral anomalies, and ASD, and more specific phenotypes of speech delays including a nonverbal phenotype and abnormal brain magnetic resonance image findings including white matter changes based on neuroradiologic examination. CONCLUSION: The consistency of clinical features among all individuals presented regardless of de novo USP7 variant type supports haploinsufficiency as a mechanism for pathogenesis and refines the clinical impact faced by affected individuals and caregivers.
Assuntos
Deficiência Intelectual/genética , Transtornos do Desenvolvimento da Linguagem/genética , Transtornos do Neurodesenvolvimento/genética , Comportamento Problema , Adolescente , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/fisiopatologia , Criança , Pré-Escolar , Deleção Cromossômica , Proteínas de Ligação a DNA/genética , Genoma Humano/genética , Haploinsuficiência/genética , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/fisiopatologia , Transtornos do Desenvolvimento da Linguagem/fisiopatologia , Transtornos do Neurodesenvolvimento/fisiopatologia , Proteínas Nucleares/genética , Fenótipo , Proteínas/genética , Sequenciamento do ExomaRESUMO
PURPOSE: Pathogenic variants in the chromatin organizer CTCF were previously reported in seven individuals with a neurodevelopmental disorder (NDD). METHODS: Through international collaboration we collected data from 39 subjects with variants in CTCF. We performed transcriptome analysis on RNA from blood samples and utilized Drosophila melanogaster to investigate the impact of Ctcf dosage alteration on nervous system development and function. RESULTS: The individuals in our cohort carried 2 deletions, 8 likely gene-disruptive, 2 splice-site, and 20 different missense variants, most of them de novo. Two cases were familial. The associated phenotype was of variable severity extending from mild developmental delay or normal IQ to severe intellectual disability. Feeding difficulties and behavioral abnormalities were common, and variable other findings including growth restriction and cardiac defects were observed. RNA-sequencing in five individuals identified 3828 deregulated genes enriched for known NDD genes and biological processes such as transcriptional regulation. Ctcf dosage alteration in Drosophila resulted in impaired gross neurological functioning and learning and memory deficits. CONCLUSION: We significantly broaden the mutational and clinical spectrum ofCTCF-associated NDDs. Our data shed light onto the functional role of CTCF by identifying deregulated genes and show that Ctcf alterations result in nervous system defects in Drosophila.
Assuntos
Fator de Ligação a CCCTC/genética , Fator de Ligação a CCCTC/metabolismo , Transtornos do Neurodesenvolvimento/genética , Animais , Criança , Cromatina/genética , Cromatina/metabolismo , Deficiências do Desenvolvimento/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Feminino , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/genética , Humanos , Deficiência Intelectual/genética , Masculino , Mutação/genética , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/metabolismo , Fatores de Transcrição/genética , Sequenciamento do Exoma/métodos , Adulto JovemRESUMO
The Loeys-Dietz syndrome (LDS) is a connective tissue disorder affecting the cardiovascular, skeletal, and ocular system. Most typically, LDS patients present with aortic aneurysms and arterial tortuosity, hypertelorism, and bifid/broad uvula or cleft palate. Initially, mutations in transforming growth factor-ß (TGF-ß) receptors (TGFBR1 and TGFBR2) were described to cause LDS, hereby leading to impaired TGF-ß signaling. More recently, TGF-ß ligands, TGFB2 and TGFB3, as well as intracellular downstream effectors of the TGF-ß pathway, SMAD2 and SMAD3, were shown to be involved in LDS. This emphasizes the role of disturbed TGF-ß signaling in LDS pathogenesis. Since most literature so far has focused on TGFBR1/2, we provide a comprehensive review on the known and some novel TGFB2/3 and SMAD2/3 mutations. For TGFB2 and SMAD3, the clinical manifestations, both of the patients previously described in the literature and our newly reported patients, are summarized in detail. This clearly indicates that LDS concerns a disorder with a broad phenotypical spectrum that is still emerging as more patients will be identified. All mutations described here are present in the corresponding Leiden Open Variant Database.
Assuntos
Estudos de Associação Genética , Síndrome de Loeys-Dietz/genética , Mutação/genética , Proteína Smad2/genética , Proteína Smad3/genética , Fator de Crescimento Transformador beta2/genética , Fator de Crescimento Transformador beta3/genética , Animais , Modelos Animais de Doenças , Humanos , Síndrome de Loeys-Dietz/diagnóstico , Camundongos , Transdução de Sinais/genéticaRESUMO
CHAMP1 encodes a protein with a function in kinetochore-microtubule attachment and in the regulation of chromosome segregation, both of which are known to be important for neurodevelopment. By trio whole-exome sequencing, we have identified de novo deleterious mutations in CHAMP1 in five unrelated individuals affected by intellectual disability with severe speech impairment, motor developmental delay, muscular hypotonia, and similar dysmorphic features including short philtrum and a tented upper and everted lover lip. In addition to two frameshift and one nonsense mutations, we found an identical nonsense mutation, c.1192C>T (p.Arg398*), in two affected individuals. All mutations, if resulting in a stable protein, are predicted to lead to the loss of the functionally important zinc-finger domains in the C terminus of the protein, which regulate CHAMP1 localization to chromosomes and the mitotic spindle, thereby providing a mechanistic understanding for their pathogenicity. We thus establish deleterious de novo mutations in CHAMP1 as a cause of intellectual disability.
Assuntos
Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Proteínas Cromossômicas não Histona/genética , Códon sem Sentido/genética , Deficiência Intelectual/genética , Fosfoproteínas/genética , Distúrbios da Fala/genética , Sequência de Bases , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Análise de Sequência de DNARESUMO
PurposeNoninvasive prenatal screening (NIPS) using cell-free DNA in maternal blood is highly sensitive for detecting fetal trisomies 21, 18, and 13. Using a genome-wide approach, other chromosome anomalies can also be detected. We report on the origin, frequency, and clinical significance of these other chromosome aberrations found in pregnancies at risk for trisomy 21, 18, or 13.MethodsWhole-genome shallow massively parallel sequencing was used and all autosomes were analyzed.ResultsIn 78 of 2,527 cases (3.1%) NIPS was indicative of trisomy 21, 18, or 13, and in 41 (1.6%) of other chromosome aberrations. The latter were of fetal (n = 10), placental (n = 22), maternal (n = 1) or unknown (n = 7). One case lacked cytogenetic follow-up. Nine of the 10 fetal cases were associated with an abnormal phenotype. Thirteen of the 22 (59%) placental aberrations were associated with fetal congenital anomalies and/or poor fetal growth (Assuntos
Aberrações Cromossômicas
, Transtornos Cromossômicos/diagnóstico
, Transtornos Cromossômicos/genética
, Testes Genéticos
, Diagnóstico Pré-Natal
, Trissomia
, Variações do Número de Cópias de DNA
, Feminino
, Testes Genéticos/métodos
, Genômica/métodos
, Humanos
, Placenta/metabolismo
, Gravidez
, Resultado da Gravidez
, Diagnóstico Pré-Natal/métodos
, Sequenciamento Completo do Genoma
RESUMO
Increasingly, high-risk pregnant women opt for non-invasive prenatal testing (NIPT) instead of invasive diagnostic testing. Since NIPT is less accurate than invasive testing, a normal NIPT result might leave women less reassured. A questionnaire study was performed among pregnant women with elevated risk for fetal aneuploidy based on first-trimester combined test (risk ≥1:200) or medical history, who were offered NIPT in the nationwide Dutch TRIDENT study. Pre- and post-test questionnaires (n = 682) included measures on: experiences with NIPT procedure, feelings of reassurance, anxiety (State-Trait Anxiety Inventory, STAI), child-related anxiety (PRAQ-R), and satisfaction. The majority (96.1%) were glad to have been offered NIPT. Most (68.5%) perceived the waiting time for NIPT results (mean: 15 days, range 5-32) as (much) too long. Most women with a normal NIPT result felt reassured (80.9%) or somewhat reassured (15.7%). Levels of anxiety and child-related anxiety were significantly lower after receiving a normal NIPT result as compared to the moment of intake (p < 0.001). Women with inadequate health literacy or a medical history (e.g. previous child with trisomy) experienced significantly higher post-test-result anxiety (Mean (M) STAI = 31.6 and 30.0, respectively) compared to those with adequate health literacy (M = 28.6) and no medical history (M = 28.6), indicating these women might benefit from extra information and/or guidance when communicating NIPT test-results. Introducing NIPT as an alternative to invasive testing, led to an offer that satisfied and largely reassured high-risk pregnant women.
Assuntos
Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Satisfação Pessoal , Diagnóstico Pré-Natal/psicologia , Adulto , Ansiedade/psicologia , Síndrome de Down/diagnóstico , Feminino , Letramento em Saúde , Humanos , Gravidez , Primeiro Trimestre da Gravidez/psicologia , Diagnóstico Pré-Natal/métodos , Inquéritos e QuestionáriosRESUMO
Plastin 3 (PLS3), a protein involved in the formation of filamentous actin (F-actin) bundles, appears to be important in human bone health, on the basis of pathogenic variants in PLS3 in five families with X-linked osteoporosis and osteoporotic fractures that we report here. The bone-regulatory properties of PLS3 were supported by in vivo analyses in zebrafish. Furthermore, in an additional five families (described in less detail) referred for diagnosis or ruling out of osteogenesis imperfecta type I, a rare variant (rs140121121) in PLS3 was found. This variant was also associated with a risk of fracture among elderly heterozygous women that was two times as high as that among noncarriers, which indicates that genetic variation in PLS3 is a novel etiologic factor involved in common, multi-factorial osteoporosis.
Assuntos
Fraturas Ósseas/genética , Glicoproteínas de Membrana/genética , Proteínas dos Microfilamentos/genética , Osteoporose/genética , Adulto , Animais , Densidade Óssea/genética , Remodelação Óssea/genética , Criança , Pré-Escolar , Feminino , Fraturas Ósseas/etiologia , Doenças Genéticas Ligadas ao Cromossomo X/genética , Heterozigoto , Humanos , Masculino , Mutação , Osteoporose/complicações , Linhagem , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Adulto Jovem , Peixe-ZebraRESUMO
PURPOSE: We aimed to determine the prevalence and phenotypic spectrum of NOTCH1 mutations in left-sided congenital heart disease (LS-CHD). LS-CHD includes aortic valve stenosis, a bicuspid aortic valve, coarctation of the aorta, and hypoplastic left heart syndrome. METHODS: NOTCH1 was screened for mutations in 428 nonsyndromic probands with LS-CHD, and family histories were obtained for all. When a mutation was detected, relatives were also tested. RESULTS: In 148/428 patients (35%), LS-CHD was familial. Fourteen mutations (3%; 5 RNA splicing mutations, 8 truncating mutations, 1 whole-gene deletion) were detected, 11 in familial disease (11/148 (7%)) and 3 in sporadic disease (3/280 (1%)). Forty-nine additional mutation carriers were identified among the 14 families, of whom 12 (25%) were asymptomatic. Most of these mutation carriers had LS-CHD, but 9 (18%) had right-sided congenital heart disease (RS-CHD) or conotruncal heart disease (CTD). Thoracic aortic aneurysms (TAAs) occurred in 6 mutation carriers (probands included 6/63 (10%)). CONCLUSION: Pathogenic mutations in NOTCH1 were identified in 7% of familial LS-CHD and in 1% of sporadic LS-CHD. The penetrance is high; a cardiovascular malformation was found in 75% of NOTCH1 mutation carriers. The phenotypic spectrum includes LS-CHD, RS-CHD, CTD, and TAA. Testing NOTCH1 for an early diagnosis in LS-CHD/RS-CHD/CTD/TAA is warranted.Genet Med 18 9, 914-923.