Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nat Commun ; 10(1): 4679, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31616000

RESUMO

Postsynaptic density (PSD) proteins have been implicated in the pathophysiology of neurodevelopmental and psychiatric disorders. Here, we present detailed clinical and genetic data for 20 patients with likely gene-disrupting mutations in TANC2-whose protein product interacts with multiple PSD proteins. Pediatric patients with disruptive mutations present with autism, intellectual disability, and delayed language and motor development. In addition to a variable degree of epilepsy and facial dysmorphism, we observe a pattern of more complex psychiatric dysfunction or behavioral problems in adult probands or carrier parents. Although this observation requires replication to establish statistical significance, it also suggests that mutations in this gene are associated with a variety of neuropsychiatric disorders consistent with its postsynaptic function. We find that TANC2 is expressed broadly in the human developing brain, especially in excitatory neurons and glial cells, but shows a more restricted pattern in Drosophila glial cells where its disruption affects behavioral outcomes.

2.
Hum Mutat ; 40(7): 908-925, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30817854

RESUMO

Pathogenic de novo variants in the X-linked gene SLC35A2 encoding the major Golgi-localized UDP-galactose transporter required for proper protein and lipid glycosylation cause a rare type of congenital disorder of glycosylation known as SLC35A2-congenital disorders of glycosylation (CDG; formerly CDG-IIm). To date, 29 unique de novo variants from 32 unrelated individuals have been described in the literature. The majority of affected individuals are primarily characterized by varying degrees of neurological impairments with or without skeletal abnormalities. Surprisingly, most affected individuals do not show abnormalities in serum transferrin N-glycosylation, a common biomarker for most types of CDG. Here we present data characterizing 30 individuals and add 26 new variants, the single largest study involving SLC35A2-CDG. The great majority of these individuals had normal transferrin glycosylation. In addition, expanding the molecular and clinical spectrum of this rare disorder, we developed a robust and reliable biochemical assay to assess SLC35A2-dependent UDP-galactose transport activity in primary fibroblasts. Finally, we show that transport activity is directly correlated to the ratio of wild-type to mutant alleles in fibroblasts from affected individuals.

3.
Am J Hum Genet ; 103(6): 1022-1029, 2018 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-30526861

RESUMO

Developmental and epileptic encephalopathies (DEEs) are a group of severe epilepsies characterized by refractory seizures and developmental impairment. Sequencing approaches have identified causal genetic variants in only about 50% of individuals with DEEs.1-3 This suggests that unknown genetic etiologies exist, potentially in the ∼98% of human genomes not covered by exome sequencing (ES). Here we describe seven likely pathogenic variants in regions outside of the annotated coding exons of the most frequently implicated epilepsy gene, SCN1A, encoding the alpha-1 sodium channel subunit. We provide evidence that five of these variants promote inclusion of a "poison" exon that leads to reduced amounts of full-length SCN1A protein. This mechanism is likely to be broadly relevant to human disease; transcriptome studies have revealed hundreds of poison exons,4,5 including some present within genes encoding other sodium channels and in genes involved in neurodevelopment more broadly.6 Future research on the mechanisms that govern neuronal-specific splicing behavior might allow researchers to co-opt this system for RNA therapeutics.


Assuntos
Epilepsias Mioclônicas/genética , Epilepsia/genética , Éxons/genética , Variação Genética/genética , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos do Neurodesenvolvimento/genética , Canais de Sódio/genética , Transcriptoma/genética
4.
Am J Hum Genet ; 101(5): 664-685, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-29100083

RESUMO

Developmental and epileptic encephalopathy (DEE) is a group of conditions characterized by the co-occurrence of epilepsy and intellectual disability (ID), typically with developmental plateauing or regression associated with frequent epileptiform activity. The cause of DEE remains unknown in the majority of cases. We performed whole-genome sequencing (WGS) in 197 individuals with unexplained DEE and pharmaco-resistant seizures and in their unaffected parents. We focused our attention on de novo mutations (DNMs) and identified candidate genes containing such variants. We sought to identify additional subjects with DNMs in these genes by performing targeted sequencing in another series of individuals with DEE and by mining various sequencing datasets. We also performed meta-analyses to document enrichment of DNMs in candidate genes by leveraging our WGS dataset with those of several DEE and ID series. By combining these strategies, we were able to provide a causal link between DEE and the following genes: NTRK2, GABRB2, CLTC, DHDDS, NUS1, RAB11A, GABBR2, and SNAP25. Overall, we established a molecular diagnosis in 63/197 (32%) individuals in our WGS series. The main cause of DEE in these individuals was de novo point mutations (53/63 solved cases), followed by inherited mutations (6/63 solved cases) and de novo CNVs (4/63 solved cases). De novo missense variants explained a larger proportion of individuals in our series than in other series that were primarily ascertained because of ID. Moreover, these DNMs were more frequently recurrent than those identified in ID series. These observations indicate that the genetic landscape of DEE might be different from that of ID without epilepsy.


Assuntos
Encefalopatias/genética , Epilepsia/genética , Mutação/genética , Criança , Pré-Escolar , Feminino , Genoma Humano/genética , Estudo de Associação Genômica Ampla/métodos , Humanos , Deficiência Intelectual/genética , Masculino , Recidiva , Convulsões/genética
5.
Am J Hum Genet ; 101(4): 516-524, 2017 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-28942967

RESUMO

Exome sequencing has readily enabled the discovery of the genetic mutations responsible for a wide range of diseases. This success has been particularly remarkable in the severe epilepsies and other neurodevelopmental diseases for which rare, often de novo, mutations play a significant role in disease risk. Despite significant progress, the high genetic heterogeneity of these disorders often requires large sample sizes to identify a critical mass of individuals with disease-causing mutations in a single gene. By pooling genetic findings across multiple studies, we have identified six individuals with severe developmental delay (6/6), refractory seizures (5/6), and similar dysmorphic features (3/6), each harboring a de novo mutation in PPP3CA. PPP3CA encodes the alpha isoform of a subunit of calcineurin. Calcineurin encodes a calcium- and calmodulin-dependent serine/threonine protein phosphatase that plays a role in a wide range of biological processes, including being a key regulator of synaptic vesicle recycling at nerve terminals. Five individuals with de novo PPP3CA mutations were identified among 4,760 trio probands with neurodevelopmental diseases; this is highly unlikely to occur by chance (p = 1.2 × 10-8) given the size and mutability of the gene. Additionally, a sixth individual with a de novo mutation in PPP3CA was connected to this study through GeneMatcher. Based on these findings, we securely implicate PPP3CA in early-onset refractory epilepsy and further support the emerging role for synaptic dysregulation in epilepsy.


Assuntos
Calcineurina/genética , Epilepsia/genética , Mutação , Transtornos do Neurodesenvolvimento/genética , Transmissão Sináptica/fisiologia , Adolescente , Adulto , Calcineurina/metabolismo , Criança , Pré-Escolar , Estudos de Coortes , Epilepsia/patologia , Exoma/genética , Feminino , Humanos , Lactente , Recém-Nascido , Síndrome de Lennox Gastaut/patologia , Masculino , Transtornos do Neurodesenvolvimento/patologia , Análise de Sequência de DNA , Índice de Gravidade de Doença , Espasmos Infantis/genética , Espasmos Infantis/patologia , Adulto Jovem
6.
JAMA Neurol ; 74(11): 1301-1311, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28846756

RESUMO

Importance: Copy number variation (CNV) is an important cause of neuropsychiatric disorders. Little is known about the role of CNV in adults with epilepsy and intellectual disability. Objectives: To evaluate the prevalence of pathogenic CNVs and identify possible candidate CNVs and genes in patients with epilepsy and intellectual disability. Design, Setting, and Participants: In this cross-sectional study, genome-wide microarray was used to evaluate a cohort of 143 adults with unexplained childhood-onset epilepsy and intellectual disability who were recruited from the Toronto Western Hospital epilepsy outpatient clinic from January 1, 2012, through December 31, 2014. The inclusion criteria were (1) pediatric seizure onset with ongoing seizure activity in adulthood, (2) intellectual disability of any degree, and (3) no structural brain abnormalities or metabolic conditions that could explain the seizures. Main Outcomes and Measures: DNA screening was performed using genome-wide microarray platforms. Pathogenicity of CNVs was assessed based on the American College of Medical Genetics guidelines. The Residual Variation Intolerance Score was used to evaluate genes within the identified CNVs that could play a role in each patient's phenotype. Results: Of the 2335 patients, 143 probands were investigated (mean [SD] age, 24.6 [10.8] years; 69 male and 74 female). Twenty-three probands (16.1%) and 4 affected relatives (2.8%) (mean [SD] age, 24.1 [6.1] years; 11 male and 16 female) presented with pathogenic or likely pathogenic CNVs (0.08-18.9 Mb). Five of the 23 probands with positive results (21.7%) had more than 1 CNV reported. Parental testing revealed de novo CNVs in 11 (47.8%), with CNVs inherited from a parent in 4 probands (17.4%). Sixteen of 23 probands (69.6%) presented with previously cataloged human genetic disorders and/or defined CNV hot spots in epilepsy. Eight nonrecurrent rare CNVs that overlapped 1 or more genes associated with intellectual disability, autism, and/or epilepsy were identified: 2p16.1-p15 duplication, 6p25.3-p25.1 duplication, 8p23.3p23.1 deletion, 9p24.3-p23 deletion, 10q11.22-q11.23 duplication, 12p13.33-13.2 duplication, 13q34 deletion, and 16p13.2 duplication. Five genes are of particular interest given their potential pathogenicity in the corresponding phenotypes and least tolerability to variation: ABAT, KIAA2022, COL4A1, CACNA1C, and SMARCA2. ABAT duplication was associated with Lennox-Gastaut syndrome and KIAA2022 deletion with Jeavons syndrome. Conclusions and Relevance: The high prevalence of pathogenic CNVs in this study highlights the importance of microarray analysis in adults with unexplained childhood-onset epilepsy and intellectual disability. Additional studies and comparison with similar cases are required to evaluate the effects of deletions and duplications that overlap specific genes.


Assuntos
Variações do Número de Cópias de DNA/genética , Epilepsia/genética , Deficiência Intelectual/genética , Adolescente , Adulto , Idade de Início , Estudos Transversais , Epilepsia/enzimologia , Feminino , Humanos , Deficiência Intelectual/epidemiologia , Masculino , Análise em Microsséries , Ontário/epidemiologia , Linhagem , Prevalência , Adulto Jovem
7.
Epilepsy Res ; 131: 1-8, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28199897

RESUMO

OBJECTIVE: Driven by advances in genomic technology and reduction in costs, next-generation sequencing (NGS) is venturing into routine clinical care. The 'real-world' clinical utility of NGS remains to be determined in focal epilepsies, which account for 60% of all epilepsies and for which the importance of genetic factors is just beginning to emerge. We investigated the diagnostic yield and management implications of whole exome sequencing (WES)-based screening of selected genes in the routine care of common focal epilepsies suspected to have a genetic basis. METHODS: We performed WES, followed by targeted analysis of 64 epilepsy genes, on 40 consecutive children and adults enrolled prospectively from routine clinical practice who had MRI-negative focal epilepsy and a family history of febrile seizures or any type of epilepsy in at least one first- or second-degree relative. Exclusion criteria were previous genetic testing, severe intellectual disability and benign focal epilepsies of childhood. RESULTS: 5/40 (12.5%) patients had a pathogenic or likely pathogenic variant, detected in SCN1A, DEPDC5, PCDH19, GABRG2 or NPRL2. Identifying a pathogenic SCN1A variant in a patient with drug-resistant epilepsy prompted to halt presurgical investigations due to concern of unfavorable post-surgical outcome. It also led in the same patient to discontinue long-standing carbamazepine therapy (a potentially aggravating drug in epilepsies due to SCN1A mutations), resulting in complete seizure control. Patients with pathogenic or likely pathogenic variants had a younger median age of seizure onset (range) compared to those without [18 months (8 months-18 years) vs 18 years (18 months-70 years), p=0.02]. SIGNIFICANCE: Our data demonstrate that WES with targeted gene analysis is an effective diagnostic tool for patients with common focal epilepsies in whom a genetic etiology is suspected. It can also influence clinical decision-making, including antiepileptic drug selection and consideration of epilepsy surgery, hence supporting its incorporation in the routine clinical care of this patient group.


Assuntos
Epilepsias Parciais/diagnóstico , Epilepsias Parciais/genética , Testes Genéticos/métodos , Variação Genética/genética , Sequenciamento Completo do Exoma/métodos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Estudos Prospectivos , Análise de Sequência de DNA/métodos , Adulto Jovem
8.
Neurology ; 86(17): 1605-12, 2016 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-27029629

RESUMO

OBJECTIVES: We report development of a targeted resequencing gene panel for focal epilepsy, the most prevalent phenotypic group of the epilepsies. METHODS: The targeted resequencing gene panel was designed using molecular inversion probe (MIP) capture technology and sequenced using massively parallel Illumina sequencing. RESULTS: We demonstrated proof of principle that mutations can be detected in 4 previously genotyped focal epilepsy cases. We searched for both germline and somatic mutations in 251 patients with unsolved sporadic or familial focal epilepsy and identified 11 novel or very rare missense variants in 5 different genes: CHRNA4, GRIN2B, KCNT1, PCDH19, and SCN1A. Of these, 2 were predicted to be pathogenic or likely pathogenic, explaining ∼0.8% of the cohort, and 8 were of uncertain significance based on available data. CONCLUSIONS: We have developed and validated a targeted resequencing panel for focal epilepsies, the most important clinical class of epilepsies, accounting for about 60% of all cases. Our application of MIP technology is an innovative approach that will be advantageous in the clinical setting because it is highly sensitive, efficient, and cost-effective for screening large patient cohorts. Our findings indicate that mutations in known genes likely explain only a small proportion of focal epilepsy cases. This is not surprising given the established clinical and genetic heterogeneity of these disorders and underscores the importance of further gene discovery studies in this complex syndrome.


Assuntos
Epilepsias Parciais/genética , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mutação , Análise de Sequência de DNA/métodos , Caderinas/genética , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Proteínas do Tecido Nervoso/genética , Canais de Potássio/genética , Receptores de N-Metil-D-Aspartato/genética , Receptores Nicotínicos/genética
9.
Ann Neurol ; 79(4): 522-34, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26704558

RESUMO

OBJECTIVE: The leading cause of epilepsy-related premature mortality is sudden unexpected death in epilepsy (SUDEP). The cause of SUDEP remains unknown. To search for genetic risk factors in SUDEP cases, we performed an exome-based analysis of rare variants. METHODS: Demographic and clinical information of 61 SUDEP cases were collected. Exome sequencing and rare variant collapsing analysis with 2,936 control exomes were performed to test for genes enriched with damaging variants. Additionally, cardiac arrhythmia, respiratory control, and epilepsy genes were screened for variants with frequency of <0.1% and predicted to be pathogenic with multiple in silico tools. RESULTS: The 61 SUDEP cases were categorized as definite SUDEP (n = 54), probable SUDEP (n = 5), and definite SUDEP plus (n = 2). We identified de novo mutations, previously reported pathogenic mutations, or candidate pathogenic variants in 28 of 61 (46%) cases. Four SUDEP cases (7%) had mutations in common genes responsible for the cardiac arrhythmia disease, long QT syndrome (LQTS). Nine cases (15%) had candidate pathogenic variants in dominant cardiac arrhythmia genes. Fifteen cases (25%) had mutations or candidate pathogenic variants in dominant epilepsy genes. No gene reached genome-wide significance with rare variant collapsing analysis; however, DEPDC5 (p = 0.00015) and KCNH2 (p = 0.0037) were among the top 30 genes, genome-wide. INTERPRETATION: A sizeable proportion of SUDEP cases have clinically relevant mutations in cardiac arrhythmia and epilepsy genes. In cases with an LQTS gene mutation, SUDEP may occur as a result of a predictable and preventable cause. Understanding the genetic basis of SUDEP may inform cascade testing of at-risk family members.


Assuntos
Arritmias Cardíacas/genética , Morte Súbita/etiologia , Epilepsia/genética , Exoma , Transtornos Respiratórios/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Genes Dominantes , Humanos , Lactente , Síndrome do QT Longo/genética , Masculino , Pessoa de Meia-Idade , Mutação , Adulto Jovem
10.
Ann Clin Transl Neurol ; 2(8): 821-30, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26339676

RESUMO

OBJECTIVE: Nocturnal frontal lobe epilepsy (NFLE) can be sporadic or autosomal dominant; some families have nicotinic acetylcholine receptor subunit mutations. We report a novel autosomal recessive phenotype in a single family and identify the causative gene. METHODS: Whole exome sequencing data was used to map the family, thereby narrowing exome search space, and then to identify the mutation. RESULTS: Linkage analysis using exome sequence data from two affected and two unaffected subjects showed homozygous linkage peaks on chromosomes 7, 8, 13, and 14 with maximum LOD scores between 1.5 and 1.93. Exome variant filtering under these peaks revealed that the affected siblings were homozygous for a novel splice site mutation (c.93+2T>C) in the PRIMA1 gene on chromosome 14. No additional PRIMA1 mutations were found in 300 other NFLE cases. The c.93+2T>C mutation was shown to lead to skipping of the first coding exon of the PRIMA1 mRNA using a minigene system. INTERPRETATION: PRIMA1 is a transmembrane protein that anchors acetylcholinesterase (AChE), an enzyme hydrolyzing acetycholine, to membrane rafts of neurons. PRiMA knockout mice have reduction of AChE and accumulation of acetylcholine at the synapse; our minigene analysis suggests that the c.93+2T>C mutation leads to knockout of PRIMA1. Mutations with gain of function effects in acetylcholine receptor subunits cause autosomal dominant NFLE. Thus, enhanced cholinergic responses are the likely cause of the severe NFLE and intellectual disability segregating in this family, representing the first recessive case to be reported and the first PRIMA1 mutation implicated in disease.

11.
Neurol Genet ; 1(2): e17, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27066554

RESUMO

OBJECTIVE: To assess the presence of DEPDC5 mutations in a cohort of patients with epileptic spasms. METHODS: We performed DEPDC5 resequencing in 130 patients with spasms, segregation analysis of variants of interest, and detailed clinical assessment of patients with possibly and likely pathogenic variants. RESULTS: We identified 3 patients with variants in DEPDC5 in the cohort of 130 patients with spasms. We also describe 3 additional patients with DEPDC5 alterations and epileptic spasms: 2 from a previously described family and a third ascertained by clinical testing. Overall, we describe 6 patients from 5 families with spasms and DEPDC5 variants; 2 arose de novo and 3 were familial. Two individuals had focal cortical dysplasia. Clinical outcome was highly variable. CONCLUSIONS: While recent molecular findings in epileptic spasms emphasize the contribution of de novo mutations, we highlight the relevance of inherited mutations in the setting of a family history of focal epilepsies. We also illustrate the utility of clinical diagnostic testing and detailed phenotypic evaluation in characterizing the constellation of phenotypes associated with DEPDC5 alterations. We expand this phenotypic spectrum to include epileptic spasms, aligning DEPDC5 epilepsies more with the recognized features of other mTORopathies.

12.
Neurology ; 83(11): 1018-21, 2014 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-25085640

RESUMO

OBJECTIVE: To determine the contribution of sequence variations in PHOX2B to sudden unexpected death in epilepsy (SUDEP). METHODS: Patients who died of SUDEP were identified in 2 major Australian cohorts, the Epilepsy Genetics research program in Melbourne and postmortem cases at the Department of Forensic Medicine in Sydney. Coding exons of the PHOX2B gene were sequenced and a fluorescent sizing assay was used to measure the PHOX2B polyalanine repeat sequence. RESULTS: Sequencing of 68 cases of SUDEP identified a 15-nucleotide deletion in the PHOX2B polyalanine repeat region in one case, a 16-year-old adolescent with focal dyscognitive seizures from age 5 years. This deletion was verified using a fluorescent sizing assay. Two synonymous variants were identified in 4 cases, but no PHOX2B polyalanine repeat expansion alleles or point mutations were found. CONCLUSIONS: The absence of PHOX2B polyalanine repeat expansion alleles or point mutations in 68 Australian cases of SUDEP, with one deletion of uncertain significance, shows that PHOX2B mutations are not a common risk factor for SUDEP.


Assuntos
Morte Súbita , Epilepsia/genética , Proteínas de Homeodomínio/genética , Fatores de Transcrição/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Austrália , Criança , Éxons , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos/genética , Sequências Repetitivas de Ácido Nucleico , Fatores de Risco , Análise de Sequência de DNA , Deleção de Sequência , Adulto Jovem
13.
Hum Mol Genet ; 23(22): 6069-80, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24939913

RESUMO

Rolandic epilepsy (RE) is the most common idiopathic focal childhood epilepsy. Its molecular basis is largely unknown and a complex genetic etiology is assumed in the majority of affected individuals. The present study tested whether six large recurrent copy number variants at 1q21, 15q11.2, 15q13.3, 16p11.2, 16p13.11 and 22q11.2 previously associated with neurodevelopmental disorders also increase risk of RE. Our association analyses revealed a significant excess of the 600 kb genomic duplication at the 16p11.2 locus (chr16: 29.5-30.1 Mb) in 393 unrelated patients with typical (n = 339) and atypical (ARE; n = 54) RE compared with the prevalence in 65,046 European population controls (5/393 cases versus 32/65,046 controls; Fisher's exact test P = 2.83 × 10(-6), odds ratio = 26.2, 95% confidence interval: 7.9-68.2). In contrast, the 16p11.2 duplication was not detected in 1738 European epilepsy patients with either temporal lobe epilepsy (n = 330) and genetic generalized epilepsies (n = 1408), suggesting a selective enrichment of the 16p11.2 duplication in idiopathic focal childhood epilepsies (Fisher's exact test P = 2.1 × 10(-4)). In a subsequent screen among children carrying the 16p11.2 600 kb rearrangement we identified three patients with RE-spectrum epilepsies in 117 duplication carriers (2.6%) but none in 202 carriers of the reciprocal deletion. Our results suggest that the 16p11.2 duplication represents a significant genetic risk factor for typical and atypical RE.


Assuntos
Duplicação Cromossômica , Cromossomos Humanos Par 16/genética , Epilepsia Rolândica/genética , Criança , Pré-Escolar , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 15/genética , Cromossomos Humanos Par 22/genética , Variações do Número de Cópias de DNA , Feminino , Humanos , Lactente , Masculino , Polimorfismo de Nucleotídeo Único
14.
Ann Neurol ; 75(5): 782-7, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24585383

RESUMO

We recently identified DEPDC5 as the gene for familial focal epilepsy with variable foci and found mutations in >10% of small families with nonlesional focal epilepsy. Here we show that DEPDC5 mutations are associated with both lesional and nonlesional epilepsies, even within the same family. DEPDC5-associated malformations include bottom-of-the-sulcus dysplasia (3 members from 2 families), and focal band heterotopia (1 individual). DEPDC5 negatively regulates the mammalian target of rapamycin (mTOR) pathway, which plays a key role in cell growth. The clinicoradiological phenotypes associated with DEPDC5 mutations share features with the archetypal mTORopathy, tuberous sclerosis, raising the possibility of therapies targeted to this pathway.


Assuntos
Encéfalo/anormalidades , Epilepsias Parciais/diagnóstico , Epilepsias Parciais/genética , Mutação/genética , Proteínas Repressoras/genética , Serina-Treonina Quinases TOR/genética , Adulto , Criança , Feminino , Humanos , Masculino , Linhagem , Adulto Jovem
15.
Nat Genet ; 45(9): 1073-6, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23933818

RESUMO

Epilepsy-aphasia syndromes (EAS) are a group of rare, severe epileptic encephalopathies of unknown etiology with a characteristic electroencephalogram (EEG) pattern and developmental regression particularly affecting language. Rare pathogenic deletions that include GRIN2A have been implicated in neurodevelopmental disorders. We sought to delineate the pathogenic role of GRIN2A in 519 probands with epileptic encephalopathies with diverse epilepsy syndromes. We identified four probands with GRIN2A variants that segregated with the disorder in their families. Notably, all four families presented with EAS, accounting for 9% of epilepsy-aphasia cases. We did not detect pathogenic variants in GRIN2A in other epileptic encephalopathies (n = 475) nor in probands with benign childhood epilepsy with centrotemporal spikes (n = 81). We report the first monogenic cause, to our knowledge, for EAS. GRIN2A mutations are restricted to this group of cases, which has important ramifications for diagnostic testing and treatment and provides new insights into the pathogenesis of this debilitating group of conditions.


Assuntos
Síndrome de Landau-Kleffner/genética , Mutação , Receptores de N-Metil-D-Aspartato/genética , Eletroencefalografia , Feminino , Humanos , Síndrome de Landau-Kleffner/diagnóstico , Masculino , Linhagem , Fenótipo
16.
Nat Genet ; 45(5): 546-51, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23542697

RESUMO

The majority of epilepsies are focal in origin, with seizures emanating from one brain region. Although focal epilepsies often arise from structural brain lesions, many affected individuals have normal brain imaging. The etiology is unknown in the majority of individuals, although genetic factors are increasingly recognized. Autosomal dominant familial focal epilepsy with variable foci (FFEVF) is notable because family members have seizures originating from different cortical regions. Using exome sequencing, we detected DEPDC5 mutations in two affected families. We subsequently identified mutations in five of six additional published large families with FFEVF. Study of families with focal epilepsy that were too small for conventional clinical diagnosis with FFEVF identified DEPDC5 mutations in approximately 12% of families (10/82). This high frequency establishes DEPDC5 mutations as a common cause of familial focal epilepsies. Shared homology with G protein signaling molecules and localization in human neurons suggest a role of DEPDC5 in neuronal signal transduction.


Assuntos
Epilepsias Parciais/genética , Exoma/genética , Predisposição Genética para Doença/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Mutação/genética , Proteínas Repressoras/genética , Adolescente , Adulto , Animais , Estudos de Casos e Controles , Células Cultivadas , Criança , Pré-Escolar , Estudos de Coortes , Biologia Computacional , Epilepsias Parciais/diagnóstico , Feminino , Imunofluorescência , Ligação Genética , Genótipo , Humanos , Lactente , Masculino , Camundongos , Pessoa de Meia-Idade , Neurônios/citologia , Neurônios/metabolismo , Linhagem , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA