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1.
Ann Neurol ; 86(6): 821-831, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31618474

RESUMO

OBJECTIVE: Epilepsy of infancy with migrating focal seizures (EIMFS) is one of the most severe developmental and epileptic encephalopathies. We delineate the genetic causes and genotype-phenotype correlations of a large EIMFS cohort. METHODS: Phenotypic and molecular data were analyzed on patients recruited through an international collaborative study. RESULTS: We ascertained 135 patients from 128 unrelated families. Ninety-three of 135 (69%) had causative variants (42/55 previously reported) across 23 genes, including 9 novel EIMFS genes: de novo dominant GABRA1, GABRB1, ATP1A3; X-linked CDKL5, PIGA; and recessive ITPA, AIMP1, KARS, WWOX. The most frequently implicated genes were KCNT1 (36/135, 27%) and SCN2A (10/135, 7%). Mosaicism occurred in 2 probands (SCN2A, GABRB3) and 3 unaffected mothers (KCNT1). Median age at seizure onset was 4 weeks, with earlier onset in the SCN2A, KCNQ2, and BRAT1 groups. Epileptic spasms occurred in 22% patients. A total of 127 patients had severe to profound developmental impairment. All but 7 patients had ongoing seizures. Additional features included microcephaly, movement disorders, spasticity, and scoliosis. Mortality occurred in 33% at median age 2 years 7 months. INTERPRETATION: We identified a genetic cause in 69% of patients with EIMFS. We highlight the genetic heterogeneity of EIMFS with 9 newly implicated genes, bringing the total number to 33. Mosaicism was observed in probands and parents, carrying critical implications for recurrence risk. EIMFS pathophysiology involves diverse molecular processes from gene and protein regulation to ion channel function and solute trafficking. ANN NEUROL 2019;86:821-831.

2.
Epilepsia ; 60(11): e121-e127, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31631344

RESUMO

Pathogenic variants in GNB5 cause an autosomal recessive neurodevelopmental disorder with neonatal sinus bradycardia. Seizures or epilepsy occurred in 10 of 22 previously reported cases, including 6 children from one family. We delineate the epileptology of GNB5 encephalopathy. Our nine patients, including five new patients, were from seven families. Epileptic spasms were the most frequent seizure type, occurring in eight of nine patients, and began at a median age of 3 months (2 months to 3 years). Focal seizures preceded spasms in three children, with onset at 7 days, 11 days, and 4 months. One child presented with convulsive status epilepticus at 6 months. Three children had burst suppression on electroencephalography (EEG), three had hypsarrhythmia, and one evolved from burst suppression to hypsarrhythmia. Background slowing was present in all after age 3 years. Magnetic resonance imaging (MRI) showed cerebral atrophy in one child and cerebellar atrophy in another. All nine had abnormal development prior to seizure onset and ultimately had profound impairment without regression. Hypotonia was present in all, with contractures developing in two older patients. All individuals had biallelic pathogenic variants in GNB5, predicted by in silico tools to result in protein truncation and loss-of-function. GNB5 developmental and epileptic encephalopathy is characterized by epileptic spasms, focal seizures, and profound impairment.

3.
Stem Cell Res ; 40: 101547, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31479876

RESUMO

GNB5 loss-of-function pathogenic variants cause IDDCA, a rare autosomal recessive human genetic disease characterized by infantile onset of intellectual disability, sinus bradycardia, hypotonia, visual abnormalities, and epilepsy. We generated human induced pluripotent stem cells (hiPSCs) from skin fibroblasts of a patient with the homozygous c.136delG frameshift variant, and a GNB5 knock-out (KO) line by CRISPR/Cas9 editing. hiPSCs express common pluripotency markers and differentiate into the three germ layers. These lines represent a powerful cellular model to study the molecular basis of GNB5-related disorders as well as offer an in vitro model for drug screening.

4.
Hum Mutat ; 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31513310

RESUMO

Developmental and epileptic encephalopathies (DEE) refer to a heterogeneous group of devastating neurodevelopmental disorders. Variants in KCNB1 have been recently reported in patients with early-onset DEE. KCNB1 encodes the α subunit of the delayed rectifier voltage-dependent potassium channel Kv 2.1. We review the 37 previously reported patients carrying 29 distinct KCNB1 variants and significantly expand the mutational spectrum describing 18 novel variants from 27 unreported patients. Most variants occur de novo and mainly consist of missense variants located on the voltage sensor and the pore domain of Kv 2.1. We also report the first inherited variant (p.Arg583*). KCNB1-related encephalopathies encompass a wide spectrum of neurodevelopmental disorders with predominant language difficulties and behavioral impairment. Eighty-five percent of patients developed epilepsies with variable syndromes and prognosis. Truncating variants in the C-terminal domain are associated with a less-severe epileptic phenotype. Overall, this report provides an up-to-date review of the mutational and clinical spectrum of KCNB1, strengthening its place as a causal gene in DEEs and emphasizing the need for further functional studies to unravel the underlying mechanisms.

5.
Pediatrics ; 144(3)2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31439621

RESUMO

Girls with pathogenic variants in FMR1, the gene responsible for Fragile X syndrome, have received relatively little attention in the literature. The reports of girls with trinucleotide expansions or deletions affecting FMR1 describe variable phenotypes; having normal intelligence and no severe neurologic sequelae is not uncommon. We reviewed epilepsy genetics research databases for girls with FMR1 pathogenic variants and seizures to characterize the spectrum of epilepsy phenotypes. We identified 4 patients, 3 of whom had drug-resistant focal epilepsy. Two had severe developmental and epileptic encephalopathy with late-onset epileptic spasms. Our findings demonstrate that FMR1 loss-of-function variants can result in severe neurologic phenotypes in girls. Similar cases may be missed because clinicians may not always perform Fragile X testing in girls, particularly those with severe neurodevelopmental impairment or late-onset spasms.

6.
Ann Neurol ; 86(2): 181-192, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177578

RESUMO

OBJECTIVE: Recent reports have described single individuals with neurodevelopmental disability (NDD) harboring heterozygous KCNQ3 de novo variants (DNVs). We sought to assess whether pathogenic variants in KCNQ3 cause NDD and to elucidate the associated phenotype and molecular mechanisms. METHODS: Patients with NDD and KCNQ3 DNVs were identified through an international collaboration. Phenotypes were characterized by clinical assessment, review of charts, electroencephalographic (EEG) recordings, and parental interview. Functional consequences of variants were analyzed in vitro by patch-clamp recording. RESULTS: Eleven patients were assessed. They had recurrent heterozygous DNVs in KCNQ3 affecting residues R230 (R230C, R230H, R230S) and R227 (R227Q). All patients exhibited global developmental delay within the first 2 years of life. Most (8/11, 73%) were nonverbal or had a few words only. All patients had autistic features, and autism spectrum disorder (ASD) was diagnosed in 5 of 11 (45%). EEGs performed before 10 years of age revealed frequent sleep-activated multifocal epileptiform discharges in 8 of 11 (73%). For 6 of 9 (67%) recorded between 1.5 and 6 years of age, spikes became near-continuous during sleep. Interestingly, most patients (9/11, 82%) did not have seizures, and no patient had seizures in the neonatal period. Voltage-clamp recordings of the mutant KCNQ3 channels revealed gain-of-function (GoF) effects. INTERPRETATION: Specific GoF variants in KCNQ3 cause NDD, ASD, and abundant sleep-activated spikes. This new phenotype contrasts both with self-limited neonatal epilepsy due to KCNQ3 partial loss of function, and with the neonatal or infantile onset epileptic encephalopathies due to KCNQ2 GoF. ANN NEUROL 2019;86:181-192.

7.
Epilepsia ; 60(3): 429-440, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30828795

RESUMO

OBJECTIVE: To investigate the occurrence of psychosis and serious behavioral problems in females with protocadherin 19 gene (PCDH19) pathogenic variants. METHODS: We evaluated whether psychosis and serious behavioral problems had occurred in 60 females (age 2-75 years) with PCDH19 pathogenic variants belonging to 35 families. Patients were identified from epilepsy genetics databases in Australia, New Zealand, the United States, and Canada. Neurologic and psychiatric disorders were diagnosed using standard methods. RESULTS: Eight of 60 females (13%) from 7 families developed a psychotic disorder: schizophrenia (6), schizoaffective disorder (1), or an unspecified psychotic disorder (1). Median age at onset of psychotic symptoms was 21 years (range 11-28 years). In our cohort of 39 females aged 11 years or older, 8 (21%) developed a psychotic disorder. Seven had ongoing seizures at onset of psychosis, with 2 continuing to have seizures when psychosis recurred. Psychotic disorders occurred in the setting of mild (4), moderate (2), or severe (1) intellectual disability, or normal intellect (1). Preexisting behavioral problems occurred in 4 patients, and autism spectrum disorder in 3. Two additional females (3%) had psychotic features with other conditions: an adolescent had recurrent episodes of postictal psychosis, and a 75-year-old woman had major depression with psychotic features. A further 3 adolescents (5%) with moderate to severe intellectual disability had onset of severe behavioral disturbance, or significant worsening. SIGNIFICANCE: We identify that psychotic disorders, including schizophrenia, are a later-onset manifestation of PCDH19 Girls Clustering Epilepsy. Affected girls and women should be carefully monitored for later-onset psychiatric disorders.

8.
Dev Med Child Neurol ; 2018 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-30402932

RESUMO

There are hundreds of compounds found in the marijuana plant, each contributing differently to the antiepileptic and psychiatric effects. Cannabidiol (CBD) has the most evidence of antiepileptic efficacy and does not have the psychoactive effects of ∆9 -tetrahydrocannabinol. CBD does not act via cannabinoid receptors and its antiepileptic mechanism of action is unknown. Despite considerable community interest in the use of CBD for paediatric epilepsy, there has been little evidence for its use apart from anecdotal reports, until the last year. Three randomized, placebo-controlled, double-blind trials in Dravet syndrome and Lennox-Gastaut syndrome found that CBD produced a 38% to 41% median reduction in all seizures compared to 13% to 19% on placebo. Similarly, CBD resulted in a 39% to 46% responder rate (50% convulsive or drop-seizure reduction) compared to 14% to 27% on placebo. CBD was well tolerated; however, sedation, diarrhoea, and decreased appetite were frequent. CBD shows similar efficacy to established antiepileptic drugs. WHAT THIS PAPER ADDS: Cannabidiol (CBD) shows similar efficacy in the severe paediatric epilepsies to other antiepileptic drugs. Careful down-titration of benzodiazepines is essential to minimize sedation with adjunctive CBD.

9.
Am J Hum Genet ; 103(2): 305-316, 2018 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-30057029

RESUMO

Next-generation sequencing combined with international data sharing has enormously facilitated identification of new disease-associated genes and mutations. This is particularly true for genetically extremely heterogeneous entities such as neurodevelopmental disorders (NDDs). Through exome sequencing and world-wide collaborations, we identified and assembled 20 individuals with de novo variants in FBXO11. They present with mild to severe developmental delay associated with a range of features including short (4/20) or tall (2/20) stature, obesity (5/20), microcephaly (4/19) or macrocephaly (2/19), behavioral problems (17/20), seizures (5/20), cleft lip or palate or bifid uvula (3/20), and minor skeletal anomalies. FBXO11 encodes a member of the F-Box protein family, constituting a subunit of an E3-ubiquitin ligase complex. This complex is involved in ubiquitination and proteasomal degradation and thus in controlling critical biological processes by regulating protein turnover. The identified de novo aberrations comprise two large deletions, ten likely gene disrupting variants, and eight missense variants distributed throughout FBXO11. Structural modeling for missense variants located in the CASH or the Zinc-finger UBR domains suggests destabilization of the protein. This, in combination with the observed spectrum and localization of identified variants and the lack of apparent genotype-phenotype correlations, is compatible with loss of function or haploinsufficiency as an underlying mechanism. We implicate de novo missense and likely gene disrupting variants in FBXO11 in a neurodevelopmental disorder with variable intellectual disability and various other features.

10.
Epilepsia ; 59(7): 1372-1380, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29873813

RESUMO

OBJECTIVE: Sudden unexpected death in epilepsy (SUDEP) is a tragic and devastating event for which the underlying pathophysiology remains poorly understood; this study investigated whether abnormalities in heart rate variability (HRV) are linked to SUDEP in patients with epilepsy due to mutations in sodium channel (SCN) genes. METHODS: We retrospectively evaluated HRV in epilepsy patients using electroencephalographic studies to study the potential contribution of autonomic dysregulation to SUDEP risk. We extracted HRV data, in wakefulness and sleep, from 80 patients with drug-resistant epilepsy, including 40 patients with mutations in SCN genes and 40 control patients with non-SCN drug-resistant epilepsy. From the SCN group, 10 patients had died of SUDEP. We compared HRV between SUDEP and non-SUDEP groups, specifically studying awake HRV and sleep:awake HRV ratios. RESULTS: The SUDEP patients had the most severe autonomic dysregulation, showing lower awake HRV and either extremely high or extremely low ratios of sleep-to-awake HRV in a subgroup analysis. A secondary analysis comparing the SCN and non-SCN groups indicated that autonomic dysfunction was slightly worse in the SCN epilepsy group. SIGNIFICANCE: These findings suggest that autonomic dysfunction is associated with SUDEP risk in patients with epilepsy due to sodium channel mutations. The relationship of HRV to SUDEP merits further study; HRV may eventually have potential as a biomarker of SUDEP risk, which would allow for more informed counseling of patients and families, and also serve as a useful outcome measure for research aimed at developing therapies and interventions to reduce SUDEP risk.

11.
Mol Psychiatry ; 2018 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-29892053

RESUMO

Epilepsy and Mental Retardation Limited to Females (EFMR) is an infantile onset disorder characterized by clusters of seizures. EFMR is due to mutations in the X-chromosome gene PCDH19, and is underpinned by cellular mosaicism due to X-chromosome inactivation in females or somatic mutation in males. This review characterizes the neuropsychiatric profile of this disorder and examines the association of clinical and molecular factors with neuropsychiatric outcomes. Data were extracted from 38 peer-reviewed original articles including 271 individual cases. We found that seizure onset ≤12 months was significantly associated (p = 4.127 × 10-7) with more severe intellectual disability, compared with onset >12 months. We identified two recurrent variants p.Asn340Ser and p.Tyr366Leufs*10 occurring in 25 (20 unrelated) and 30 (11 unrelated) cases, respectively. PCDH19 mutations were associated with psychiatric comorbidities in approximately 60% of females, 80% of affected mosaic males, and reported in nine hemizygous males. Hyperactive, autistic, and obsessive-compulsive features were most frequently reported. There were no genotype-phenotype associations in the individuals with recurrent variants or the group overall. Age at seizure onset can be used to provide more informative prognostic counseling.

13.
Epilepsy Res ; 139: 43-50, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29175563

RESUMO

OBJECTIVE: Previous studies have shown moderate agreement between physicians when diagnosing epilepsy, but have included small numbers. The EpiNet study group was established to undertake multicentre clinical trials in epilepsy. Before commencing trials, we wanted to determine levels of agreement between physicians from different countries and different health systems when diagnosing epilepsy, specific seizure types and etiologies. METHODS: 30 Case scenarios describing six children and 24 adults with paroxysmal events (21 epileptic seizures, nine non-epileptic attacks) were presented to physicians with an interest in epilepsy. Physicians were asked how likely was a diagnosis of epilepsy; if seizures were generalised or focal; and the likely etiology. For 23 cases, clinical information was presented in Step 1, and investigations in Step 2. RESULTS: 189 Participants from 36 countries completed the 30 cases. Levels of agreement were determined for 154 participants who provided details regarding their clinical experience. There was substantial agreement for diagnosis of epilepsy (kappa=0.61); agreement was fair to moderate for seizure type(s) (kappa=0.40) and etiology (kappa=0.41). For 23 cases with two steps, agreement increased from step 1 to step 2 for diagnosis of epilepsy (kappa 0.56-0.70), seizure type(s) (kappa 0.38-0.52), and etiology (kappa 0.38-0.47). Agreement was better for 53 epileptologists (diagnosis of epilepsy, kappa=0.66) than 56 neurologists with a special interest in epilepsy (kappa=0.58). Levels of agreement differed slightly between physicians practicing in different parts of the world, between child and adult neurologists, and according to one's experience with epilepsy. CONCLUSION: Although there is substantial agreement when epileptologists diagnose epilepsy, there is less agreement for diagnoses of seizure types and etiology. Further education of physicians regarding semiology of different seizure types is required. Differences in approach to diagnosis, both between physicians and between countries, could impact negatively on clinical trials of anti-epileptic drugs.

14.
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
15.
Neurology ; 89(10): 1035-1042, 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28794249

RESUMO

OBJECTIVE: To define a distinct SCN1A developmental and epileptic encephalopathy with early onset, profound impairment, and movement disorder. METHODS: A case series of 9 children were identified with a profound developmental and epileptic encephalopathy and SCN1A mutation. RESULTS: We identified 9 children 3 to 12 years of age; 7 were male. Seizure onset was at 6 to 12 weeks with hemiclonic seizures, bilateral tonic-clonic seizures, or spasms. All children had profound developmental impairment and were nonverbal and nonambulatory, and 7 of 9 required a gastrostomy. A hyperkinetic movement disorder occurred in all and was characterized by dystonia and choreoathetosis with prominent oral dyskinesia and onset from 2 to 20 months of age. Eight had a recurrent missense SCN1A mutation, p.Thr226Met. The remaining child had the missense mutation p.Pro1345Ser. The mutation arose de novo in 8 of 9; for the remaining case, the mother was negative and the father was unavailable. CONCLUSIONS: Here, we present a phenotype-genotype correlation for SCN1A. We describe a distinct SCN1A phenotype, early infantile SCN1A encephalopathy, which is readily distinguishable from the well-recognized entities of Dravet syndrome and genetic epilepsy with febrile seizures plus. This disorder has an earlier age at onset, profound developmental impairment, and a distinctive hyperkinetic movement disorder, setting it apart from Dravet syndrome. Remarkably, 8 of 9 children had the recurrent missense mutation p.Thr226Met.


Assuntos
Deficiências do Desenvolvimento/genética , Epilepsia/genética , Hipercinese/genética , Mutação de Sentido Incorreto , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Idade de Início , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Criança , Pré-Escolar , Deficiências do Desenvolvimento/diagnóstico por imagem , Deficiências do Desenvolvimento/fisiopatologia , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/fisiopatologia , Epilepsia/diagnóstico por imagem , Epilepsia/fisiopatologia , Feminino , Humanos , Hipercinese/diagnóstico por imagem , Hipercinese/fisiopatologia , Masculino , Fenótipo
16.
Epilepsia Open ; 2(1): 20-31, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29750210

RESUMO

Objective: EpiNet was established to encourage epilepsy research. EpiNet is used for multicenter cohort studies and investigator-led trials. Physicians must be accredited to recruit patients into trials. Here, we describe the accreditation process for the EpiNet-First trials. Methods: Physicians with an interest in epilepsy were invited to assess 30 case scenarios to determine the following: whether patients have epilepsy; the nature of the seizures (generalized, focal); and the etiology. Information was presented in two steps for 23 cases. The EpiNet steering committee determined that 21 cases had epilepsy. The steering committee determined by consensus which responses were acceptable for each case. We chose a subset of 18 cases to accredit investigators for the EpiNet-First trials. We initially focused on 12 cases; to be accredited, investigators could not diagnose epilepsy in any case that the steering committee determined did not have epilepsy. If investigators were not accredited after assessing 12 cases, 6 further cases were considered. When assessing the 18 cases, investigators could be accredited if they diagnosed one of six nonepilepsy patients as having possible epilepsy but could make no other false-positive errors and could make only one error regarding seizure classification. Results: Between December 2013 and December 2014, 189 physicians assessed the 30 cases. Agreement with the steering committee regarding the diagnosis at step 1 ranged from 47% to 100%, and improved when information regarding tests was provided at step 2. One hundred five of the 189 physicians (55%) were accredited for the EpiNet-First trials. The kappa value for diagnosis of epilepsy across all 30 cases for accredited physicians was 0.70. Significance: We have established criteria for accrediting physicians using EpiNet. New investigators can be accredited by assessing 18 case scenarios. We encourage physicians with an interest in epilepsy to become EpiNet-accredited and to participate in these investigator-led clinical trials.

17.
Am J Hum Genet ; 99(2): 423-9, 2016 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-27453577

RESUMO

Hypothalamic hamartoma (HH) with gelastic epilepsy is a well-recognized drug-resistant epilepsy syndrome of early life.(1) Surgical resection allows limited access to the small deep-seated lesions that cause the disease. Here, we report the results of a search for somatic mutations in paired hamartoma- and leukocyte-derived DNA samples from 38 individuals which we conducted by using whole-exome sequencing (WES), chromosomal microarray (CMA), and targeted resequencing (TRS) of candidate genes. Somatic mutations were identified in genes involving regulation of the sonic hedgehog (Shh) pathway in 14/38 individuals (37%). Three individuals had somatic mutations in PRKACA, which encodes a cAMP-dependent protein kinase that acts as a repressor protein in the Shh pathway, and four subjects had somatic mutations in GLI3, an Shh pathway gene associated with HH. In seven other individuals, we identified two recurrent and three single brain-tissue-specific, large copy-number or loss-of-heterozygosity (LOH) variants involving multiple Shh genes, as well as other genes without an obvious biological link to the Shh pathway. The Shh pathway genes in these large somatic lesions include the ligand itself (SHH and IHH), the receptor SMO, and several other Shh downstream pathway members, including CREBBP and GLI2. Taken together, our data implicate perturbation of the Shh pathway in at least 37% of individuals with the HH epilepsy syndrome, consistent with the concept of a developmental pathway brain disease.


Assuntos
Epilepsias Parciais/genética , Hamartoma/genética , Proteínas Hedgehog/metabolismo , Doenças Hipotalâmicas/genética , Mutação/genética , Transdução de Sinais/genética , Proteína de Ligação a CREB/genética , Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/genética , Exoma/genética , Feminino , Humanos , Fatores de Transcrição Kruppel-Like/genética , Perda de Heterozigosidade , Masculino , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Proteína Gli2 com Dedos de Zinco , Proteína Gli3 com Dedos de Zinco
18.
Am J Med Genet A ; 170A(4): 1059-63, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26708157

RESUMO

Mutations in COL4A1 are well described and result in brain abnormalities manifesting with severe neurological deficits including cerebral palsy, intellectual disability, and focal epilepsy. Families with mutations in COL4A2 are now emerging with a similar phenotype. We describe a family with an autosomal dominant disorder comprising porencephaly, focal epilepsy, and lens opacities, which was negative for mutations in COL4A1. Using whole exome sequencing of three affected individuals from three generations, we identified a rare variant in COL4A2. This COL4A2 (c.2399G>A, p.G800E, CCDS41907.1) variant was predicted to be damaging by multiple bioinformatics tools and affects an invariable glycine residue that is essential for the formation of collagen IV heterotrimers. The cataracts identified in this family expand the phenotypic spectrum associated with mutations in COL4A2 and highlight the increasing overlap with phenotypes associated with COL4A1 mutations.


Assuntos
Catarata/diagnóstico , Catarata/genética , Colágeno Tipo IV/genética , Genes Dominantes , Mutação , Porencefalia/diagnóstico , Porencefalia/genética , Adolescente , Adulto , Idoso , Encéfalo/patologia , Exoma , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imagem por Ressonância Magnética , Masculino , Linhagem
19.
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
20.
EBioMedicine ; 2(9): 1063-70, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26501104

RESUMO

Sudden unexpected death in epilepsy (SUDEP) represents the most severe degree of the spectrum of epilepsy severity and is the commonest cause of epilepsy-related premature mortality. The precise pathophysiology and the genetic architecture of SUDEP remain elusive. Aiming to elucidate the genetic basis of SUDEP, we analysed rare, protein-changing variants from whole-exome sequences of 18 people who died of SUDEP, 87 living people with epilepsy and 1479 non-epilepsy disease controls. Association analysis revealed a significantly increased genome-wide polygenic burden per individual in the SUDEP cohort when compared to epilepsy (P = 5.7 × 10(- 3)) and non-epilepsy disease controls (P = 1.2 × 10(- 3)). The polygenic burden was driven both by the number of variants per individual, and over-representation of variants likely to be deleterious in the SUDEP cohort. As determined by this study, more than a thousand genes contribute to the observed polygenic burden within the framework of this study. Subsequent gene-based association analysis revealed five possible candidate genes significantly associated with SUDEP or epilepsy, but no one single gene emerges as common to the SUDEP cases. Our findings provide further evidence for a genetic susceptibility to SUDEP, and suggest an extensive polygenic contribution to SUDEP causation. Thus, an overall increased burden of deleterious variants in a highly polygenic background might be important in rendering a given individual more susceptible to SUDEP. Our findings suggest that exome sequencing in people with epilepsy might eventually contribute to generating SUDEP risk estimates, promoting stratified medicine in epilepsy, with the eventual aim of reducing an individual patient's risk of SUDEP.


Assuntos
Epilepsia/genética , Variação Genética , Estudo de Associação Genômica Ampla/métodos , Herança Multifatorial/genética , Adulto , Causas de Morte , Morte Súbita , Epilepsia/mortalidade , Epilepsia/patologia , Exoma/genética , Feminino , Estudos de Associação Genética/métodos , Predisposição Genética para Doença/genética , Humanos , Masculino , Fatores de Risco , Análise de Sequência de DNA/métodos , Índice de Gravidade de Doença
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