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1.
Am J Hum Genet ; 109(4): 601-617, 2022 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-35395208

RESUMEN

Neurodevelopmental disorders are highly heterogenous conditions resulting from abnormalities of brain architecture and/or function. FBXW7 (F-box and WD-repeat-domain-containing 7), a recognized developmental regulator and tumor suppressor, has been shown to regulate cell-cycle progression and cell growth and survival by targeting substrates including CYCLIN E1/2 and NOTCH for degradation via the ubiquitin proteasome system. We used a genotype-first approach and global data-sharing platforms to identify 35 individuals harboring de novo and inherited FBXW7 germline monoallelic chromosomal deletions and nonsense, frameshift, splice-site, and missense variants associated with a neurodevelopmental syndrome. The FBXW7 neurodevelopmental syndrome is distinguished by global developmental delay, borderline to severe intellectual disability, hypotonia, and gastrointestinal issues. Brain imaging detailed variable underlying structural abnormalities affecting the cerebellum, corpus collosum, and white matter. A crystal-structure model of FBXW7 predicted that missense variants were clustered at the substrate-binding surface of the WD40 domain and that these might reduce FBXW7 substrate binding affinity. Expression of recombinant FBXW7 missense variants in cultured cells demonstrated impaired CYCLIN E1 and CYCLIN E2 turnover. Pan-neuronal knockdown of the Drosophila ortholog, archipelago, impaired learning and neuronal function. Collectively, the data presented herein provide compelling evidence of an F-Box protein-related, phenotypically variable neurodevelopmental disorder associated with monoallelic variants in FBXW7.


Asunto(s)
Proteína 7 que Contiene Repeticiones F-Box-WD , Trastornos del Neurodesarrollo , Ubiquitinación , Proteína 7 que Contiene Repeticiones F-Box-WD/química , Proteína 7 que Contiene Repeticiones F-Box-WD/genética , Proteína 7 que Contiene Repeticiones F-Box-WD/metabolismo , Células Germinativas , Mutación de Línea Germinal , Humanos , Trastornos del Neurodesarrollo/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo
2.
Clin Genet ; 105(3): 294-301, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38044714

RESUMEN

Calmodulin-binding transcriptional activator 1 (CAMTA1) is highly expressed in the brain and plays a role in cell cycle regulation, cell differentiation, regulation of long-term memory, and initial development, maturation, and survival of cerebellar neurons. The existence of human neurological phenotypes, including cerebellar dysfunction with variable cognitive and behavioral abnormalities (CECBA), associated with CAMTA1 variants, has further supported its role in brain functions. In this study, we phenotypically and molecularly characterize the largest cohort of individuals (n = 26) with 23 novel CAMTA1 variants (frameshift-7, nonsense-6, splicing-1, initiation codon-1, missense-5, and intragenic deletions-3) and compare the findings with all previously reported cases (total = 53). We show that the most notable phenotypic findings are developmental delay/intellectual disability, unsteady or uncoordinated gait, hypotonia, behavioral problems, and eye abnormalities. In addition, there is a high incidence of dysarthria, dysgraphia, microcephaly, gastrointestinal abnormalities, sleep difficulties, and nonspecific brain MRI findings; a few of which have been under-reported. More than one third of the variants in this cohort were inherited from an asymptomatic or mildly affected parent suggesting reduced penetrance and variable expressivity. Our cohort provides a comprehensive characterization of the spectrum of phenotypes and genotypes among individuals with CECBA and the large data will facilitate counseling and formulating management plans and surveillance recommendations for these individuals.


Asunto(s)
Discapacidad Intelectual , Factores de Transcripción , Humanos , Encéfalo/metabolismo , Proteínas de Unión al Calcio/genética , Genotipo , Discapacidad Intelectual/genética , Fenotipo , Transactivadores/genética , Factores de Transcripción/genética
3.
Epilepsia ; 64(2): 443-455, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36318112

RESUMEN

OBJECTIVE: Mutations in the genes encoding neuronal ion channels are a common cause of Mendelian neurological diseases. We sought to identify novel de novo sequence variants in cases with early infantile epileptic phenotypes and neurodevelopmental anomalies. METHODS: Following clinical diagnosis, we performed whole exome sequencing of the index cases and their parents. Identified channel variants were expressed in Xenopus oocytes and their functional properties assessed using two-electrode voltage clamp. RESULTS: We identified novel de novo variants in KCNA6 in four unrelated individuals variably affected with neurodevelopmental disorders and seizures with onset in the first year of life. Three of the four identified mutations affect the pore-lining S6 α-helix of KV 1.6. A prominent finding of functional characterization in Xenopus oocytes was that the channel variants showed only minor effects on channel activation but slowed channel closure and shifted the voltage dependence of deactivation in a hyperpolarizing direction. Channels with a mutation affecting the S6 helix display dominant effects on channel deactivation when co-expressed with wild-type KV 1.6 or KV 1.1 subunits. SIGNIFICANCE: This is the first report of de novo nonsynonymous variants in KCNA6 associated with neurological or any clinical features. Channel variants showed a consistent effect on channel deactivation, slowing the rate of channel closure following normal activation. This specific gain-of-function feature is likely to underlie the neurological phenotype in our patients. Our data highlight KCNA6 as a novel channelopathy gene associated with early infantile epileptic phenotypes and neurodevelopmental anomalies.


Asunto(s)
Epilepsia , Trastornos del Neurodesarrollo , Humanos , Epilepsia/genética , Mutación/genética , Convulsiones/genética , Canal de Potasio Kv1.6/genética
4.
Brain ; 145(9): 2991-3009, 2022 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-34431999

RESUMEN

We report detailed functional analyses and genotype-phenotype correlations in 392 individuals carrying disease-causing variants in SCN8A, encoding the voltage-gated Na+ channel Nav1.6, with the aim of describing clinical phenotypes related to functional effects. Six different clinical subgroups were identified: Group 1, benign familial infantile epilepsy (n = 15, normal cognition, treatable seizures); Group 2, intermediate epilepsy (n = 33, mild intellectual disability, partially pharmaco-responsive); Group 3, developmental and epileptic encephalopathy (n = 177, severe intellectual disability, majority pharmaco-resistant); Group 4, generalized epilepsy (n = 20, mild to moderate intellectual disability, frequently with absence seizures); Group 5, unclassifiable epilepsy (n = 127); and Group 6, neurodevelopmental disorder without epilepsy (n = 20, mild to moderate intellectual disability). Those in Groups 1-3 presented with focal or multifocal seizures (median age of onset: 4 months) and focal epileptiform discharges, whereas the onset of seizures in patients with generalized epilepsy was later (median: 42 months) with generalized epileptiform discharges. We performed functional studies expressing missense variants in ND7/23 neuroblastoma cells and primary neuronal cultures using recombinant tetrodotoxin-insensitive human Nav1.6 channels and whole-cell patch-clamping. Two variants causing developmental and epileptic encephalopathy showed a strong gain-of-function (hyperpolarizing shift of steady-state activation, strongly increased neuronal firing rate) and one variant causing benign familial infantile epilepsy or intermediate epilepsy showed a mild gain-of-function (defective fast inactivation, less increased firing). In contrast, all three variants causing generalized epilepsy induced a loss-of-function (reduced current amplitudes, depolarizing shift of steady-state activation, reduced neuronal firing). Functional effects were known for 170 individuals. All 136 individuals carrying a functionally tested gain-of-function variant had either focal (n = 97, Groups 1-3) or unclassifiable (n = 39) epilepsy, whereas 34 individuals with a loss-of-function variant had either generalized (n = 14), no (n = 11) or unclassifiable (n = 6) epilepsy; only three had developmental and epileptic encephalopathy. Computational modelling in the gain-of-function group revealed a significant correlation between the severity of the electrophysiological and clinical phenotypes. Gain-of-function variant carriers responded significantly better to sodium channel blockers than to other anti-seizure medications, and the same applied for all individuals in Groups 1-3. In conclusion, our data reveal clear genotype-phenotype correlations between age at seizure onset, type of epilepsy and gain- or loss-of-function effects of SCN8A variants. Generalized epilepsy with absence seizures is the main epilepsy phenotype of loss-of-function variant carriers and the extent of the electrophysiological dysfunction of the gain-of-function variants is a main determinant of the severity of the clinical phenotype in focal epilepsies. Our pharmacological data indicate that sodium channel blockers present a treatment option in SCN8A-related focal epilepsy with onset in the first year of life.


Asunto(s)
Epilepsia Generalizada , Síndromes Epilépticos , Discapacidad Intelectual , Canal de Sodio Activado por Voltaje NAV1.6 , Epilepsia Generalizada/tratamiento farmacológico , Epilepsia Generalizada/genética , Síndromes Epilépticos/tratamiento farmacológico , Síndromes Epilépticos/genética , Estudios de Asociación Genética , Humanos , Lactante , Discapacidad Intelectual/genética , Mutación , Canal de Sodio Activado por Voltaje NAV1.6/genética , Pronóstico , Convulsiones/tratamiento farmacológico , Convulsiones/genética , Bloqueadores de los Canales de Sodio/uso terapéutico
5.
Am J Hum Genet ; 101(1): 139-148, 2017 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-28686853

RESUMEN

We report 15 individuals with de novo pathogenic variants in WDR26. Eleven of the individuals carry loss-of-function mutations, and four harbor missense substitutions. These 15 individuals comprise ten females and five males, and all have intellectual disability with delayed speech, a history of febrile and/or non-febrile seizures, and a wide-based, spastic, and/or stiff-legged gait. These subjects share a set of common facial features that include a prominent maxilla and upper lip that readily reveal the upper gingiva, widely spaced teeth, and a broad nasal tip. Together, these features comprise a recognizable facial phenotype. We compared these features with those of chromosome 1q41q42 microdeletion syndrome, which typically contains WDR26, and noted that clinical features are consistent between the two subsets, suggesting that haploinsufficiency of WDR26 contributes to the pathology of 1q41q42 microdeletion syndrome. Consistent with this, WDR26 loss-of-function single-nucleotide mutations identified in these subjects lead to nonsense-mediated decay with subsequent reduction of RNA expression and protein levels. We derived a structural model of WDR26 and note that missense variants identified in these individuals localize to highly conserved residues of this WD-40-repeat-containing protein. Given that WDR26 mutations have been identified in ∼1 in 2,000 of subjects in our clinical cohorts and that WDR26 might be poorly annotated in exome variant-interpretation pipelines, we would anticipate that this disorder could be more common than currently appreciated.


Asunto(s)
Facies , Marcha/genética , Haploinsuficiencia/genética , Discapacidad Intelectual/genética , Proteínas/genética , Convulsiones/genética , Proteínas Adaptadoras Transductoras de Señales , Secuencia de Aminoácidos , Secuencia de Bases , Preescolar , Deleción Cromosómica , Femenino , Crecimiento y Desarrollo/genética , Humanos , Discapacidad Intelectual/complicaciones , Masculino , Mutación/genética , Proteínas/química , Estabilidad del ARN/genética , Convulsiones/complicaciones , Síndrome
6.
Am J Hum Genet ; 97(6): 922-32, 2015 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-26637982

RESUMEN

We describe an X-linked genetic syndrome associated with mutations in TAF1 and manifesting with global developmental delay, intellectual disability (ID), characteristic facial dysmorphology, generalized hypotonia, and variable neurologic features, all in male individuals. Simultaneous studies using diverse strategies led to the identification of nine families with overlapping clinical presentations and affected by de novo or maternally inherited single-nucleotide changes. Two additional families harboring large duplications involving TAF1 were also found to share phenotypic overlap with the probands harboring single-nucleotide changes, but they also demonstrated a severe neurodegeneration phenotype. Functional analysis with RNA-seq for one of the families suggested that the phenotype is associated with downregulation of a set of genes notably enriched with genes regulated by E-box proteins. In addition, knockdown and mutant studies of this gene in zebrafish have shown a quantifiable, albeit small, effect on a neuronal phenotype. Our results suggest that mutations in TAF1 play a critical role in the development of this X-linked ID syndrome.


Asunto(s)
Discapacidades del Desarrollo/genética , Histona Acetiltransferasas/genética , Discapacidad Intelectual/genética , Enfermedades Neurodegenerativas/genética , Factores Asociados con la Proteína de Unión a TATA/genética , Factor de Transcripción TFIID/genética , Adolescente , Animales , Niño , Preescolar , Discapacidades del Desarrollo/metabolismo , Discapacidades del Desarrollo/patología , Modelos Animales de Enfermedad , Elementos E-Box , Facies , Familia , Regulación de la Expresión Génica , Histona Acetiltransferasas/metabolismo , Humanos , Lactante , Patrón de Herencia , Discapacidad Intelectual/metabolismo , Discapacidad Intelectual/patología , Masculino , Mutación , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neurodegenerativas/patología , Linaje , Fenotipo , Transducción de Señal , Factores Asociados con la Proteína de Unión a TATA/metabolismo , Factor de Transcripción TFIID/metabolismo , Adulto Joven , Pez Cebra
7.
Hum Mutat ; 36(10): 1009-1014, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26173930

RESUMEN

We report a new syndrome due to loss-of-function variants in the heterogeneous nuclear ribonucleoprotein K gene (HNRNPK). We describe two probands: one with a de novo frameshift (NM_002140.3: c.953+1dup), and the other with a de novo splice donor site variant (NM_002140.3: c.257G>A). Both probands have intellectual disability, a shared unique craniofacial phenotype, and connective tissue and skeletal abnormalities. The identification of this syndrome was made possible by a new online tool, GeneMatcher, which facilitates connections between clinicians and researchers based on shared interest in candidate genes. This report demonstrates that new Web-based approaches can be effective in helping investigators solve exome sequencing projects, and also highlights the newer paradigm of "reverse phenotyping," where characterization of syndromic features follows the identification of genetic variants.


Asunto(s)
Anomalías Múltiples/genética , Anomalías Craneofaciales/genética , Bases de Datos Genéticas , Discapacidad Intelectual/genética , Atrofia Muscular/genética , Polimorfismo de Nucleótido Simple , Ribonucleoproteínas/genética , Adolescente , Niño , Predisposición Genética a la Enfermedad , Ribonucleoproteína Heterogénea-Nuclear Grupo K , Humanos , Difusión de la Información , Masculino , Fenotipo , Programas Informáticos , Navegador Web
8.
Am J Med Genet A ; 164A(2): 441-8, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24357076

RESUMEN

A clinically recognizable syndrome associated with 1q41q42 microdeletion has recently been described in the literature (OMIM 612530). Patients with microdeletions in this region of chromosome 1 typically have developmental delay, characteristic dysmorphic features, and a predisposition to seizures. Malformations such as congenital diaphragmatic hernia and cleft lip have also been described. There has been considerable interest in mapping the smallest region of overlap for this syndrome in order to identify the critical pathogenic genes. The smallest region of overlap has recently been refined to a region encompassing four genes. Using array comparative genome hybridization (array CGH), we have identified a female with a 590-kB deletion within chromosome1q41q42. This patient's deletion further refines the previously defined region of overlap to a single gene, FBXO28. We propose that FBXO28 is a possible candidate causative gene contributing to the intellectual disability and seizure phenotype observed in 1q41q42 microdeletion syndrome.


Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 1 , Discapacidad Intelectual/genética , Proteínas Ligasas SKP Cullina F-box/genética , Convulsiones/genética , Adolescente , Niño , Preescolar , Hibridación Genómica Comparativa , Facies , Femenino , Humanos , Hibridación Fluorescente in Situ , Lactante , Recién Nacido , Síndrome
9.
Am J Med Genet A ; 164A(3): 676-84, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24357594

RESUMEN

Shprintzen-Goldberg syndrome (OMIM #182212) is a connective tissue disorder characterized by craniosynostosis, distinctive craniofacial features, skeletal abnormalities, marfanoid body habitus, aortic dilatation, and intellectual disability. Mutations in exon 1 of SKI have recently been identified as being responsible for approximately 90% of reported individuals diagnosed clinically with Shprintzen-Goldberg syndrome. SKI is a known regulator of TGFß signaling. Therefore, like Marfan syndrome and Loeys-Dietz syndrome, Shprintzen-Goldberg syndrome is likely caused by deregulated TGFß signals, explaining the considerable phenotypic overlap between these three disorders. We describe two additional patients with exon 1 SKI mutations and review the clinical features and literature of Shprintzen-Goldberg syndrome.


Asunto(s)
Aracnodactilia/diagnóstico , Aracnodactilia/genética , Craneosinostosis/diagnóstico , Craneosinostosis/genética , Proteínas de Unión al ADN/genética , Exones , Síndrome de Marfan/diagnóstico , Síndrome de Marfan/genética , Mutación Missense , Proteínas Proto-Oncogénicas/genética , Encéfalo/patología , Preescolar , Facies , Femenino , Humanos , Imagen por Resonancia Magnética , Fenotipo , Médula Espinal/patología , Tomografía Computarizada por Rayos X
10.
Brain Commun ; 5(5): fcad222, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37794925

RESUMEN

LNPK encodes a conserved membrane protein that stabilizes the junctions of the tubular endoplasmic reticulum network playing crucial roles in diverse biological functions. Recently, homozygous variants in LNPK were shown to cause a neurodevelopmental disorder (OMIM#618090) in four patients displaying developmental delay, epilepsy and nonspecific brain malformations including corpus callosum hypoplasia and variable impairment of cerebellum. We sought to delineate the molecular and phenotypic spectrum of LNPK-related disorder. Exome or genome sequencing was carried out in 11 families. Thorough clinical and neuroradiological evaluation was performed for all the affected individuals, including review of previously reported patients. We identified 12 distinct homozygous loss-of-function variants in 16 individuals presenting with moderate to profound developmental delay, cognitive impairment, regression, refractory epilepsy and a recognizable neuroimaging pattern consisting of corpus callosum hypoplasia and signal alterations of the forceps minor ('ear-of-the-lynx' sign), variably associated with substantia nigra signal alterations, mild brain atrophy, short midbrain and cerebellar hypoplasia/atrophy. In summary, we define the core phenotype of LNPK-related disorder and expand the list of neurological disorders presenting with the 'ear-of-the-lynx' sign suggesting a possible common underlying mechanism related to endoplasmic reticulum-phagy dysfunction.

11.
iScience ; 25(10): 105092, 2022 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-36157585

RESUMEN

Epilepsy and neurodevelopmental disorders can arise from pathogenic variants of KCNQ (Kv7) channels. A patient with developmental and epileptic encephalopathy exhibited an in-frame deletion of histidine 260 on Kv7.2. Coexpression of Kv7.2 mutant (mut) subunits with Kv7.3 invoked a decrease in current density, a depolarizing shift in voltage for activation, and a decrease in membrane conductance. Biotinylation revealed an increased level of surface Kv7.2mut compared to Kv7.3 with no change in total membrane protein expression. Super-resolution and FRET imaging confirmed heteromeric channel formation and a higher expression density of Kv7.2mut. Cannabidiol (1 µM) offset the effects of Kv7.2mut by inducing a hyperpolarizing shift in voltage for activation independent of CB1 or CB2 receptors. These data reveal that the ability for cannabidiol to reduce the effects of a pathogenic Kv7.2 variant supports its use as a potential therapeutic to reduce seizure activity.

12.
Handb Clin Neurol ; 173: 307-326, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32958182

RESUMEN

Neurodevelopmental disorders encompass a broad range of conditions, which include autism, epilepsy, and intellectual disability. These disorders are relatively common and have associated clinical and genetic heterogeneity. Technology has driven much of our understanding of these diseases and their genetic underlying mechanisms, particularly highlighted by the study of large cohorts with comparative genomic hybridization and the more recent implementation of next-generation sequencing (NGS). The mapping of copy number variants throughout the genome has highlighted the recurrent, highly penetrant, de novo variation in syndromic forms of neurodevelopmental disease. NGS of affected individuals and their parents led to a dramatic shift in our understanding as these studies showed that a significant proportion of affected individuals carry rare, de novo variants within single genes that explain their disease presentation. Deep sequencing studies further implicate mosaicism as another mechanism of disease. However, it has also become clear that while rare variants explain a significant proportion of sporadic neurodevelopmental disease, rare variation still does not fully account for the familial clustering and high heritability observed. Common variants, including those within these known disease genes, are also shown to contribute significantly to overall risk. There is also increasing awareness of the important contribution of epigenetic factors and gene-environment interactions.


Asunto(s)
Discapacidad Intelectual , Trastornos del Neurodesarrollo , Hibridación Genómica Comparativa , Variaciones en el Número de Copia de ADN/genética , Genoma , Humanos , Discapacidad Intelectual/genética , Trastornos del Neurodesarrollo/genética
13.
Epilepsia Open ; 5(4): 562-573, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33336127

RESUMEN

OBJECTIVE: A spectrum of seizure disorders is linked to mutations in Kv7.2 and Kv7.3 channels. Linking functional effects of identified mutations to their clinical presentation requires ongoing characterization of newly identified variants. In this study, we identified and functionally characterized a previously unreported mutation in the selectivity filter of Kv7.3. METHODS: Next-generation sequencing was used to identify the Kv7.3[T313I] mutation in a family affected by neonatal seizures. Electrophysiological approaches were used to characterize the functional effects of this mutation on ion channels expressed in Xenopus laevis oocytes. RESULTS: Substitution of residue 313 from threonine to isoleucine (Kv7.3[T313I]) likely disrupts a critical intersubunit hydrogen bond. Characterization of the mutation in homomeric Kv7.3 channels demonstrated a total loss of channel function. Assembly in heteromeric channels (with Kv7.2) leads to modest suppression of total current when expressed in Xenopus laevis oocytes. Using a Kv7 activator with distinct effects on homomeric Kv7.2 vs heteromeric Kv7.2/Kv7.3 channels, we demonstrated that assembly of Kv7.2 and Kv7.3[T313I] generates functional channels. SIGNIFICANCE: Biophysical and clinical effects of the T313I mutation are consistent with Kv7.3 mutations previously identified in cases of pharmacoresponsive self-limiting neonatal epilepsy. These findings expand our description of functionally characterized Kv7 channel variants and report new methods to distinguish molecular mechanisms of channel mutations.

16.
Eur J Hum Genet ; 26(9): 1272-1281, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29904177

RESUMEN

Au-Kline syndrome (AKS, OMIM 616580) is a multiple malformation syndrome, first reported in 2015, associated with intellectual disability. AKS has been associated with de novo loss-of-function variants in HNRNPK (heterogeneous ribonucleoprotein K), and to date, only four of these patients have been described in the literature. Recently, an additional patient with a missense variant in HNRNPK was also reported. These patients have striking facial dysmorphic features, including long palpebral fissures, ptosis, deeply grooved tongue, broad nose, and down-turned mouth. Patients frequently also have skeletal and connective tissue anomalies, craniosynostosis, congenital heart malformations, and renal anomalies. In this report, we describe six new patients and review the clinical information on all reported AKS patients, further delineating the phenotype of AKS. There are now a total of 9 patients with de novo loss-of-function variants in HNRNPK, one individual with a de novo missense variant in addition to 3 patients with de novo deletions of 9q21.32 that encompass HNRNPK. While there is considerable overlap between AKS and Kabuki syndrome (KS), these additional patients demonstrate that AKS does have a distinct facial gestalt and phenotype that can be differentiated from KS. This growing AKS patient cohort also informs an emerging approach to management and health surveillance for these patients.


Asunto(s)
Anomalías Múltiples/genética , Ribonucleoproteína Heterogénea-Nuclear Grupo K/genética , Discapacidad Intelectual/genética , Fenotipo , Anomalías Múltiples/patología , Niño , Eliminación de Gen , Humanos , Lactante , Discapacidad Intelectual/patología , Mutación con Pérdida de Función , Masculino , Mutación Missense , Síndrome , Adulto Joven
17.
Nat Commun ; 9(1): 4619, 2018 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-30397230

RESUMEN

Chromatin remodeling is of crucial importance during brain development. Pathogenic alterations of several chromatin remodeling ATPases have been implicated in neurodevelopmental disorders. We describe an index case with a de novo missense mutation in CHD3, identified during whole genome sequencing of a cohort of children with rare speech disorders. To gain a comprehensive view of features associated with disruption of this gene, we use a genotype-driven approach, collecting and characterizing 35 individuals with de novo CHD3 mutations and overlapping phenotypes. Most mutations cluster within the ATPase/helicase domain of the encoded protein. Modeling their impact on the three-dimensional structure demonstrates disturbance of critical binding and interaction motifs. Experimental assays with six of the identified mutations show that a subset directly affects ATPase activity, and all but one yield alterations in chromatin remodeling. We implicate de novo CHD3 mutations in a syndrome characterized by intellectual disability, macrocephaly, and impaired speech and language.


Asunto(s)
ADN Helicasas/genética , Discapacidades del Desarrollo/genética , Trastornos del Lenguaje/genética , Megalencefalia/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Mutación Missense , Trastornos del Neurodesarrollo/genética , Dominios Proteicos/genética , Trastornos del Habla/genética , Adenosina Trifosfatasas , Preescolar , Ensamble y Desensamble de Cromatina , Femenino , Expresión Génica , Genotipo , Células HEK293 , Humanos , Discapacidad Intelectual/genética , Masculino , Modelos Moleculares , Fenotipo , Secuenciación Completa del Genoma
18.
Clin Cancer Res ; 12(18): 5557-69, 2006 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-17000693

RESUMEN

PURPOSE: This study aims to identify a novel therapeutic agent for head and neck cancer and to evaluate its antitumor efficacy. EXPERIMENTAL DESIGN: A cell-based and phenotype-driven high-throughput screening of approximately 2,400 biologically active or clinically used compounds was done using a tetrazolium-based assay on FaDu (hypopharyngeal squamous cancer) and NIH 3T3 (untransformed mouse embryonic fibroblast) cells, with secondary screening done on C666-1 (nasopharyngeal cancer) and GM05757 (primary normal human fibroblast) lines. The "hit" compound was assayed for efficacy in combination with standard therapeutics on a panel of human cancer cell lines. Furthermore, its mode of action (using transmission electron microscopy and flow cytometry) and its in vivo efficacy (using xenograft models) were evaluated. RESULTS: Benzethonium chloride was identified as a novel cancer-specific compound. For benzethonium (48-hour incubation), the dose required to reduce cell viability by 50% was 3.8 micromol/L in FaDu, 42.2 micromol/L in NIH 3T3, 5.3 micromol/L in C666-1, and 17.0 micromol/L in GM05757. In vitro, this compound did not interfere with the effects of cisplatin, 5-fluorouracil, or gamma-irradiation. Benzethonium chloride induced apoptosis and activated caspases after 12 hours. Loss of mitochondrial membrane potential (DeltaPsiM) preceded cytosolic Ca2+ increase and cell death. In vivo, benzethonium chloride ablated the tumor-forming ability of FaDu cells, delayed the growth of xenograft tumors, and combined additively with local tumor radiation therapy. Evaluation of benzethonium chloride on the National Cancer Institute/NIH Developmental Therapeutics Program 60 human cancer cell lines revealed broad-range antitumor activity. CONCLUSIONS: This high-throughput screening identified a novel antimicrobial compound with significant broad-spectrum anticancer activity.


Asunto(s)
Antineoplásicos/aislamiento & purificación , Bencetonio/aislamiento & purificación , Ensayos de Selección de Medicamentos Antitumorales/métodos , Análisis de Matrices Tisulares/métodos , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Bencetonio/farmacología , Bencetonio/uso terapéutico , Calcio/metabolismo , Caspasas/metabolismo , Proliferación Celular/efectos de los fármacos , Proliferación Celular/efectos de la radiación , Supervivencia Celular/efectos de los fármacos , Quimioterapia Combinada , Femenino , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/radioterapia , Humanos , Potenciales de la Membrana/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Membranas Mitocondriales/efectos de los fármacos , Modelos Biológicos , Células 3T3 NIH , Neoplasias/tratamiento farmacológico , Neoplasias/radioterapia , Fármacos Sensibilizantes a Radiaciones/farmacología , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto/métodos
19.
Mol Cancer Ther ; 5(9): 2234-40, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16985057

RESUMEN

Despite advances in surgery, radiation, and chemotherapy, novel therapeutics are needed for head and neck cancer treatment. The objective of this current study was to evaluate alexidine dihydrochloride as a novel compound lead for head and neck cancers. Using a tetrazolium-based assay, the dose required to reduce cell viability by 50% (ED50) was found to be approximately 1.8 micromol/L in FaDu (human hypopharyngeal squamous cancer) and approximately 2.6 micromol/L in C666-1 (human undifferentiated nasopharyngeal cancer) cells. In contrast, the ED50 values were much higher in untransformed cells, specifically at approximately 8.8 micromol/L in GM05757 (primary normal human fibroblast), approximately 8.9 micromol/L in HNEpC (primary normal human nasal epithelial), and approximately 19.6 micromol/L in NIH/3T3 (mouse embryonic fibroblast) cells. Alexidine dihydrochloride did not interfere with the activities of cisplatin, 5-fluorouracil, or radiation, and interacted in a less-than-additive manner. DNA content analyses and Hoechst 33342 staining revealed that this compound induced apoptosis. Alexidine dihydrochloride-induced mitochondrial damage was visualized using transmission electron microscopy. Mitochondrial membrane potential (DeltaPsiM) depolarization was detectable after only 3 hours of treatment, and was followed by cytosolic Ca2+ increase along with loss of membrane integrity/cell death. Caspase-2 and caspase-9 activities were detectable at 12 hours, caspase-8 at 24 hours, and caspase-3 at 48 hours. FaDu cell clonogenic survival was reduced to < 5% with 1 micromol/L alexidine dihydrochloride, and, correspondingly, this compound decreased the in vivo tumor-forming potential of FaDu cells. Thus, we have identified alexidine dihydrochloride as the first bisbiguanide compound with anticancer specificity.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Biguanidas/farmacología , Carcinoma de Células Escamosas/tratamiento farmacológico , Neoplasias Hipofaríngeas/tratamiento farmacológico , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Biguanidas/administración & dosificación , Carcinoma de Células Escamosas/patología , Caspasa 2/metabolismo , Caspasa 9/metabolismo , Cisplatino/administración & dosificación , Activación Enzimática/efectos de los fármacos , Femenino , Fluorouracilo/administración & dosificación , Humanos , Neoplasias Hipofaríngeas/patología , Potenciales de la Membrana/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Membranas Mitocondriales/efectos de los fármacos , Membranas Mitocondriales/fisiología , Células 3T3 NIH , Ensayos Antitumor por Modelo de Xenoinjerto
20.
Oncogene ; 24(19): 3196-205, 2005 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-15735680

RESUMEN

Tumor necrosis factor (TNF) induces both cell death and survival signals. NF-kappaB, a transcription factor activated by TNF, is critical for controlling survival signals through trans-activation of downstream target genes. However, few NF-kappaB target survival genes have been identified with direct roles in oncogenesis. We report that platelet-derived growth factor B (PDGF-B), an oncogene and growth factor, is highly induced by TNF in fibroblasts in an NF-kappaB-dependent manner. PDGF-B can rescue NF-kappaB-deficient fibroblasts from TNF-mediated killing, and inhibition of PDGF-B signaling sensitizes wild-type cells to TNF-induced death. Interestingly, PDGF-B-transformed NIH-3T3 cells are even more highly sensitized to TNF-induced cell death with PDGF-B inhibition. Our results suggest that while normal cells contain multiple TNF-induced survival signals, tumor cells may favor a specific survival gene that is abnormally upregulated in order to evade death signals.


Asunto(s)
Proteínas Proto-Oncogénicas c-sis/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Células 3T3 , Animales , Apoptosis , Northern Blotting , Western Blotting , Caspasa 3 , Caspasas/metabolismo , Muerte Celular , Línea Celular Transformada , Separación Celular , Supervivencia Celular , Células Cultivadas , Medio de Cultivo Libre de Suero/farmacología , Fibroblastos/metabolismo , Citometría de Flujo , Quinasa I-kappa B , Ratones , Modelos Biológicos , FN-kappa B/metabolismo , Células 3T3 NIH , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores del Factor de Crecimiento Derivado de Plaquetas/metabolismo , Transducción de Señal , Factores de Tiempo , Transcripción Genética , Regulación hacia Arriba
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