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1.
Epilepsy Res ; 156: 106181, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31394400

RESUMO

Infantile spasms (IS) is a developmental and epileptic encephalopathy with heterogeneous etiologies including many genetic causes. Genetic studies have identified pathogenic variants in over 30 genes as causes of IS. Many of these genetic causes are extremely rare, with only one reported incidence in an individual with IS. To better understand the genetic landscape of IS, we used targeted sequencing to screen 42 candidate IS genes and 53 established developmental and epileptic encephalopathy genes in 92 individual with IS. We identified a genetic diagnosis for 7.6% of our cohort, including pathogenic variants in KCNB1 (n = 2), GNAO1 (n = 1), STXBP1 (n = 1), SLC35A2 (n = 1), TBL1XR1 (n = 1), and KIF1A (n = 1). Our data emphasize the genetic heterogeneity of IS and will inform the diagnosis and management of individuals with this devastating disorder.

2.
Genet Med ; 21(10): 2216-2223, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30976099

RESUMO

PURPOSE: To provide a detailed electroclinical description and expand the phenotype of PIGT-CDG, to perform genotype-phenotype correlation, and to investigate the onset and severity of the epilepsy associated with the different genetic subtypes of this rare disorder. Furthermore, to use computer-assisted facial gestalt analysis in PIGT-CDG and to the compare findings with other glycosylphosphatidylinositol (GPI) anchor deficiencies. METHODS: We evaluated 13 children from eight unrelated families with homozygous or compound heterozygous pathogenic variants in PIGT. RESULTS: All patients had hypotonia, severe developmental delay, and epilepsy. Epilepsy onset ranged from first day of life to two years of age. Severity of the seizure disorder varied from treatable seizures to severe neonatal onset epileptic encephalopathies. The facial gestalt of patients resembled that of previously published PIGT patients as they were closest to the center of the PIGT cluster in the clinical face phenotype space and were distinguishable from other gene-specific phenotypes. CONCLUSION: We expand our knowledge of PIGT. Our cases reaffirm that the use of genetic testing is essential for diagnosis in this group of disorders. Finally, we show that computer-assisted facial gestalt analysis accurately assigned PIGT cases to the multiple congenital anomalies-hypotonia-seizures syndrome phenotypic series advocating the additional use of next-generation phenotyping technology.

3.
Epilepsia ; 60(5): 830-844, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30968951

RESUMO

OBJECTIVE: Pathogenic variants in SCN8A have been associated with a wide spectrum of epilepsy phenotypes, ranging from benign familial infantile seizures (BFIS) to epileptic encephalopathies with variable severity. Furthermore, a few patients with intellectual disability (ID) or movement disorders without epilepsy have been reported. The vast majority of the published SCN8A patients suffer from severe developmental and epileptic encephalopathy (DEE). In this study, we aimed to provide further insight on the spectrum of milder SCN8A-related epilepsies. METHODS: A cohort of 1095 patients were screened using a next generation sequencing panel. Further patients were ascertained from a network of epilepsy genetics clinics. Patients with severe DEE and BFIS were excluded from the study. RESULTS: We found 36 probands who presented with an SCN8A-related epilepsy and normal intellect (33%) or mild (61%) to moderate ID (6%). All patients presented with epilepsy between age 1.5 months and 7 years (mean = 13.6 months), and 58% of these became seizure-free, two-thirds on monotherapy. Neurological disturbances included ataxia (28%) and hypotonia (19%) as the most prominent features. Interictal electroencephalogram was normal in 41%. Several recurrent variants were observed, including Ile763Val, Val891Met, Gly1475Arg, Gly1483Lys, Phe1588Leu, Arg1617Gln, Ala1650Val/Thr, Arg1872Gln, and Asn1877Ser. SIGNIFICANCE: With this study, we explore the electroclinical features of an intermediate SCN8A-related epilepsy with mild cognitive impairment, which is for the majority a treatable epilepsy.

5.
Eur J Hum Genet ; 26(8): 1121-1131, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29706646

RESUMO

Malformations of cortical development (MCDs) manifest with structural brain anomalies that lead to neurologic sequelae, including epilepsy, cerebral palsy, developmental delay, and intellectual disability. To investigate the underlying genetic architecture of patients with disorders of cerebral cortical development, a cohort of 54 patients demonstrating neuroradiologic signs of MCDs was investigated. Individual genomes were interrogated for single-nucleotide variants (SNV) and copy number variants (CNV) with whole-exome sequencing and chromosomal microarray studies. Variation affecting known MCDs-associated genes was found in 16/54 cases, including 11 patients with SNV, 2 patients with CNV, and 3 patients with both CNV and SNV, at distinct loci. Diagnostic pathogenic SNV and potentially damaging variants of unknown significance (VUS) were identified in two groups of seven individuals each. We demonstrated that de novo variants are important among patients with MCDs as they were identified in 10/16 individuals with a molecular diagnosis. Three patients showed changes in known MCDs genes  and a clinical phenotype beyond the usual characteristics observed, i.e., phenotypic expansion, for a particular known disease gene clinical entity. We also discovered 2 likely candidate genes, CDH4, and ASTN1, with human and animal studies supporting their roles in brain development, and 5 potential candidate genes. Our findings emphasize genetic heterogeneity of MCDs disorders and postulate potential novel candidate genes involved in cerebral cortical development.

6.
Neurol Neurochir Pol ; 51(1): 1-6, 2017 Jan - Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27667361

RESUMO

OBJECTIVE: Dopa-responsive dystonia (DRD) is a rare form of hereditary movement disorder with onset in childhood, characterized by gait difficulties due to postural dystonia with marked improvement after low doses of levodopa. Mutations in the GCH1 gene are the most common cause of DRD, however, in some cases when the disease is associated with parkinsonism mutations in the PARK2 gene may be identified. The aim of this study was to analyze and compare genotype-phenotype correlation. MATERIAL/PARTICIPANTS: Four families with inter- and intrafamilial variability of progressive gait dysfunction due to lower limb dystonia occurring in childhood or adolescence were included in the analysis. METHODS: General and neurological examination was performed for all affected family members and asymptomatic mutation carriers. The molecular analysis encompassed GCH1 and PARK2 genes. RESULTS: All probands were clinically diagnosed with DRD. The molecular analysis revealed, however, that the dopa-responsive dystonia phenotype was caused by a mutation in the GCH1 gene in three families and in the PARK2 gene in one family. Obtained results allowed to establish the final diagnosis for all families as DYT5a or early-onset Parkinson disease (EO-PD). CONCLUSIONS: Reported cases confirm that the DRD phenotype may have heterogeneous genetic background and may be caused by point mutations or rearrangements in the GCH1 gene as well as in the PARK2 gene. Differential diagnosis and genetic tests covering the analysis of genes causative for DRD and EO-PD should be obligatory in both disorders diagnostics as DRD, mainly adolescent onset dystonia, may be associated with parkinsonism.


Assuntos
Distúrbios Distônicos/genética , GTP Cicloidrolase/genética , Doença de Parkinson/genética , Ubiquitina-Proteína Ligases/genética , Adolescente , Adulto , Idade de Início , Criança , Distúrbios Distônicos/fisiopatologia , Feminino , Genótipo , Humanos , Masculino , Doença de Parkinson/fisiopatologia , Linhagem , Fenótipo
7.
Dev Period Med ; 21(4): 317-327, 2017.
Artigo em Polonês | MEDLINE | ID: mdl-29291359

RESUMO

Epilepsy is common neurological condition affecting 0.8-1% of the human population. Since 80% of patients are under 20 years of age, it is mainly a disease of the developmental period. The causes of epilepsy are heterogeneous, but the disease has always been considered a genetic disorder, which no longer doubted. Epilepsy genetics has undergone a revolution since the discovery of the first gene responsible for epilepsy. This is mainly because of introduction of the next generation sequencing as research and diagnostic tool, and transition from studies of pedigrees with epilepsy to the analysis of cases of epileptic encephalopathies. In a short time more than 50 early infantile epileptic encephalopathies were recognized due to the causative genes. Whole exome or targeted panel sequencing has been used as a diagnostic tool with a diagnostic yield of about 30-40%. The "genetic diagnosis" that is obtained makes it possible to introduce targeted treatment in an increasing number of cases. Since epileptic encephalopaties are often regarded as the model disease for epilepsy, these therapeutic strategies can provide treatment for patients with common epilepsies.

8.
Neurology ; 87(11): 1140-51, 2016 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-27521439

RESUMO

OBJECTIVE: To delineate phenotypic heterogeneity, we describe the clinical features of a cohort of patients with GABRA1 gene mutations. METHODS: Patients with GABRA1 mutations were ascertained through an international collaboration. Clinical, EEG, and genetic data were collected. Functional analysis of 4 selected mutations was performed using the Xenopus laevis oocyte expression system. RESULTS: The study included 16 novel probands and 3 additional family members with a disease-causing mutation in the GABRA1 gene. The phenotypic spectrum varied from unspecified epilepsy (1), juvenile myoclonic epilepsy (2), photosensitive idiopathic generalized epilepsy (1), and generalized epilepsy with febrile seizures plus (1) to severe epileptic encephalopathies (11). In the epileptic encephalopathy group, the patients had seizures beginning between the first day of life and 15 months, with a mean of 7 months. Predominant seizure types in all patients were tonic-clonic in 9 participants (56%) and myoclonic seizures in 5 (31%). EEG showed a generalized photoparoxysmal response in 6 patients (37%). Four selected mutations studied functionally revealed a loss of function, without a clear genotype-phenotype correlation. CONCLUSIONS: GABRA1 mutations make a significant contribution to the genetic etiology of both benign and severe epilepsy syndromes. Myoclonic and tonic-clonic seizures with pathologic response to photic stimulation are common and shared features in both mild and severe phenotypes.


Assuntos
Epilepsia/genética , Mutação , Receptores de GABA-A/genética , Adolescente , Adulto , Animais , Encéfalo/fisiopatologia , Criança , Pré-Escolar , Estudos de Coortes , Epilepsia/fisiopatologia , Feminino , Estudos de Associação Genética , Humanos , Lactente , Masculino , Potenciais da Membrana/fisiologia , Pessoa de Meia-Idade , Oócitos , Fenótipo , Receptores de GABA-A/metabolismo , Xenopus laevis , Ácido gama-Aminobutírico/metabolismo
9.
J Appl Genet ; 57(3): 349-55, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26906906

RESUMO

Friedreich ataxia (FRDA) is the most common hereditary ataxia. It is an autosomal recessive disorder caused by mutations of the FXN gene, mainly the biallelic expansion of the (GAA)n repeats in its first intron. Heterozygous expansion/point mutations or deletions are rare; no patients with two point mutations or a point mutation/deletion have been described, suggesting that loss of the FXN gene product, frataxin, is lethal. This is why routine FRDA molecular diagnostics is focused on (GAA)n expansion analysis. Additional tests are considered only in cases of heterozygous expansion carriers and an atypical clinical picture. Analyses of the parent's carrier status, together with diagnostic tests, are performed in rare cases, and, because of that, we may underestimate the frequency of deletions. Even though FXN deletions are characterised as 'exquisitely rare,' we were able to identify one case (2.4 %) of a (GAA)n expansion/exonic deletion in a group of 41 probands. This was a patient with very early onset of disease with rapid progression of gait instability and hypertrophic cardiomyopathy. We compared the patient's clinical data to expansion/deletion carriers available in the literature and suggest that, in clinical practice, the FXN deletion test should be taken into account in patients with early-onset, rapid progressive ataxia and severe scoliosis.


Assuntos
Ataxia de Friedreich/diagnóstico , Testes Genéticos/métodos , Deleção de Sequência , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Éxons , Feminino , Ataxia de Friedreich/genética , Aconselhamento Genético , Heterozigoto , Humanos , Proteínas de Ligação ao Ferro/genética , Masculino , Linhagem , Mutação Puntual
10.
Postepy Biochem ; 61(1): 18-24, 2015.
Artigo em Polonês | MEDLINE | ID: mdl-26281350

RESUMO

Huntington's disease is a progressive neurodegenerative disorder of genetic origin that still lacks an effective treatment. Recently, a number of new attempts have been undertaken to develop a successful molecular therapy for this incurable condition. The novel approaches employ, among others, some new methods to selectively silence the mutated gene or to neutralize its toxic protein product. This paper reviews all major strategies that are currently considered for molecular therapy of Huntington's disease while discussing their potential effectiveness regarding the treatment of both the Huntington's disease and a large group of related neurodegenerative disorders associated with abnormal protein aggregation.


Assuntos
Doença de Huntington/terapia , Terapia de Alvo Molecular/métodos , Inativação Gênica , Humanos , Doença de Huntington/genética
11.
Neurol Neurochir Pol ; 49(4): 258-66, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26188943

RESUMO

OBJECTIVE: The aim of this study was to analyze the intra-/interfamilial phenotypic heterogeneity due to variants at the highly evolutionary conservative p.Arg1596 residue in the Nav1.1 subunit. MATERIALS/PARTICIPANTS: Among patients referred for analysis of the SCN1A gene one recurrent, heritable mutation was found in families enrolled into the study. Probands from those families even clinically diagnosed with atypical Dravet syndrome (DS), generalized epilepsy with febrile seizures plus (GEFS+), and focal epilepsy, had heterozygous p.Arg1596 His/Cys missense substitutions, c.4787G>T and c.4786C>T in the SCN1A gene. METHOD: Full clinical evaluation, including cognitive development, neurological examination, EEGs, MRI was performed in probands and affected family members in developmental age. The whole SCN1A gene sequencing was performed for all probands. The exon 25, where the identified missense substitutions are localized, was directly analyzed for the other family members. RESULTS: Mutation of the SCN1A p.1596Arg was identified in three families, in one case substitution p.Arg1596Cys and in two cases p.Arg1596His. Both mutations were previously described as pathogenic and causative for DS, GEFS+ and focal epilepsy. Spectrum of phenotypes among presented families with p.Arg1596 mutations shows heterogeneity ranged from asymptomatic cases, through FS and FS+ to GEFS+/Panayiotopoulos syndrome and epilepsies with and without febrile seizures, and epileptic encephalopathy such as DS. Phenotypes differ among patients displaying both focal and generalized epilepsies. Some patients demonstrated additionally Asperger syndrome and ataxia. CONCLUSION: Clinical picture heterogeneity of the patients carrying mutation of the same residue indicates the involvement of the other factors influencing the SCN1A gene mutations' penetrance.


Assuntos
Epilepsias Mioclônicas/genética , Epilepsias Parciais/genética , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Adulto , Criança , Pré-Escolar , Epilepsias Mioclônicas/fisiopatologia , Epilepsias Parciais/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Adulto Jovem
12.
J Appl Genet ; 56(4): 451-461, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25833766

RESUMO

Parkinson's disease (PD) is a common neurodegenerative disorder affecting mostly elderly people, although there is a group of patients developing so-called early-onset PD (EOPD). Mutations in the PARK2 gene are a common cause of autosomal recessive EOPD. PARK2 belongs to the family of extremely large human genes which are often localised in genomic common fragile sites (CFSs) and exhibit gross instability. PARK2 is located in the centre of FRA6E, the third most mutation-susceptible CFS of the human genome. The gene encompasses a region of 1.3 Mbp and, among its mutations, large rearrangements of single or multiple exons account for around 50%. We performed an analysis of the PARK2 gene in a group of 344 PD patients with EOPD and classical form of the disease. Copy number changes were first identified using multiplex ligation probe amplification (MLPA), with their ranges characterised by array comparative genomic hybridisation (aCGH). Exact breakpoints were mapped using direct sequencing. Rearrangements were found in eight subjects, including five deletions and three duplications. Rearrangements were mostly non-recurrent and no repetitive sequences or extended homologies were identified in the regions flanking breakpoint junctions. However, in most cases, 1-3 bp microhomologies were present, strongly suggesting that microhomology-mediated mechanisms, specifically non-homologous end joining (NHEJ) and fork stalling and template switching (FoSTeS)/microhomology-mediated break-induced replication (MMBIR), are predominantly involved in the rearrangement processes in this genomic region.


Assuntos
Instabilidade Genômica , Doença de Parkinson/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Idoso , Sequência de Bases , Hibridização Genômica Comparativa , Variações do Número de Cópias de DNA , Análise Mutacional de DNA , Feminino , Duplicação Gênica , Rearranjo Gênico , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Linhagem , Polônia , Deleção de Sequência
13.
Nat Genet ; 47(4): 393-399, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25751627

RESUMO

Epileptic encephalopathies are a phenotypically and genetically heterogeneous group of severe epilepsies accompanied by intellectual disability and other neurodevelopmental features. Using next-generation sequencing, we identified four different de novo mutations in KCNA2, encoding the potassium channel KV1.2, in six isolated patients with epileptic encephalopathy (one mutation recurred three times independently). Four individuals presented with febrile and multiple afebrile, often focal seizure types, multifocal epileptiform discharges strongly activated by sleep, mild to moderate intellectual disability, delayed speech development and sometimes ataxia. Functional studies of the two mutations associated with this phenotype showed almost complete loss of function with a dominant-negative effect. Two further individuals presented with a different and more severe epileptic encephalopathy phenotype. They carried mutations inducing a drastic gain-of-function effect leading to permanently open channels. These results establish KCNA2 as a new gene involved in human neurodevelopmental disorders through two different mechanisms, predicting either hyperexcitability or electrical silencing of KV1.2-expressing neurons.


Assuntos
Epilepsia/genética , Canal de Potássio Kv1.2/genética , Mutação , Espasmos Infantis/genética , Adulto , Sequência de Aminoácidos , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Humanos , Lactente , Masculino , Linhagem , Adulto Jovem
14.
Dev Period Med ; 19(4): 454-63, 2015 Oct-Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26982753

RESUMO

THE AIM: To present the molecular and clinical characteristics of three children with glucose deficiency syndrome, an inborn rare metabolic disease, caused by mutations in the SLC2A1 gene. MATERIAL AND METHODS: The investigation was carried out in three children: two girls and one boy showing symptoms of GLUT1 deficiency syndrome (GLUT1-DS). They were referred for SLC2A1 gene analysis. RESULTS: The presence of mutations in all of them was confirmed. Only point mutations were identified, two missenses p.Gly132Ser, p.Arg212Cys and amino acid insertion p.Ser_Val227insValProPro. In two cases the mutations arose de novo, one was heritable of paternal origin. CONCLUSIONS: GLUT1-DS shows high clinical variability. It should be suspected in children of any age presenting with single features or a combination of any form of intractable epilepsy with seizures of various types, movement disorders and paroxysmal events, especially triggered by exercise, exertion, or fasting, and any unexplainable neurological deterioration. The basic diagnostic hallmarks of GLUT1-DS are CSF hypoglycorrhachia and lowered CSF/Blood serum glucose ratio. This is why lumbar punction should be considered more frequently than it is in practice being performed nowadays. Antiepileptic drug treatment may be ineffective or even potentially detrimental. Early identification and molecular confirmation of GLUT1-DS is important, because this is a metabolic disorder and patients should as soon as possible primarily be treated with a ketogenic diet.


Assuntos
Epilepsia/genética , Transportador de Glucose Tipo 1/deficiência , Transportador de Glucose Tipo 1/genética , Criança , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Mutação , Doenças Neurodegenerativas/genética
15.
Cleft Palate Craniofac J ; 52(5): e161-7, 2015 09.
Artigo em Inglês | MEDLINE | ID: mdl-25489771

RESUMO

OBJECTIVE: To examine the role of the IRF6 mutations in Polish families with Van der Woude syndrome and popliteal pterygium syndrome and to determine the effect of IRF6 single nucleotide polymorphisms (rs7552506, rs2013162, and rs2235375) on cleft lip and/or palate susceptibility. DESIGN: IRF6 mutation screening was performed by direct sequencing of all coding exons of the gene and their flanking intronic regions. Cosegregation analysis was performed to establish the relation of single nucleotide polymorphisms and cleft lip and/or palate phenotypes. PATIENTS: We screened the IRF6 gene in eight families with clinical recognition of Van der Woude syndrome and popliteal pterygium syndrome. RESULTS: In five families we identified pathogenic mutations, all affecting the DNA-binding or the protein-binding domain of IRF6. Two of the mutations were novel-a missense mutation Arg31Thr and a small deletion Trp40Glyfs*23. In most cases we found also a haplotype of three single nucleotide polymorphisms-rs7552506, rs2013162, and rs2235375. The association of the single nucleotide polymorphisms and cleft lip and/or palate susceptibility has been previously published. The variants did not cosegregate with phenotype in examined families nor did they cosegregate with pathogenic mutations. The single nucleotide polymorphisms were deemed not causative, due to their presence in unaffected family members. CONCLUSIONS: Two novel mutations (Arg31Thr and Trp40Glyfs*23) in the IRF6 gene were identified to be causative for Van der Woude and popliteal pterygium syndromes. In the present study no association between the single nucleotide polymorphisms rs7552506, rs2013162, and rs2235375 and the cleft lip and/or palate phenotype was found. The hypothesis, whether the haplotype of the three single nucleotide polymorphisms was correlated with IRF6 expression level, demands further investigation.


Assuntos
Anormalidades Múltiplas/genética , Fenda Labial/genética , Fissura Palatina/genética , Cistos/genética , Anormalidades do Olho/genética , Dedos/anormalidades , Fatores Reguladores de Interferon/genética , Articulação do Joelho/anormalidades , Lábio/anormalidades , Deformidades Congênitas das Extremidades Inferiores/genética , Polimorfismo de Nucleotídeo Único , Sindactilia/genética , Anormalidades Urogenitais/genética , Feminino , Haplótipos , Humanos , Masculino , Mutação de Sentido Incorreto , Linhagem , Fenótipo , Polônia
16.
Eur J Paediatr Neurol ; 19(1): 78-86, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25439737

RESUMO

BACKGROUND: We present clinical and molecular findings of a patient with ceroid-lipofuscinosis CLN7, with a compound heterozygous mutation of the MFSD8 gene, with Rett syndrome clinical signs onset and a later development of full picture of vLINCL. CASE PRESENTATION: A 7 years-old female patient with normal development until the age 12 months, developed Rett like clinical picture (psychomotor regression, microcephaly, stereotypic hands movements in the midline, hyperventilation episodes) present at the onset of her condition (age 18 months), features still present at the initial evaluation in our clinic at age 5 years. RESULTS: MECP2 (methyl CpG binding protein 2) gene mutation was negative. At age 6 years she was readmitted for severe ataxia and blindness, seizures, and severe developmental regression leading to NCL (neuronal ceroid lipofuscinosis) suspicion. EEG showed slow background with IRDA (intermittent rhythmic delta activity). A conjunctive biopsy showed abnormal curvilinear and fingerprint lysosomal deposits, and genetic analysis revealed two heterozygous mutations of MFSD8 gene (c.881C > A p.Thr294Lys and c.754 + 2T > A) each inherited from carrier parents and a heterozygous variant (c.470A>C p.Asp157Ala) of CLN5 gene. CONCLUSION: NCL should be suspected and MFSD8 genetic testing should also be considered in patients with Rett like phenotype at onset and negative MECP2 mutation. Such cases should be carefully and frequently re-evaluated in order to avoid delayed diagnosis and offer proper genetic advice to the family. In our knowledge, this might be the first case of CLN7 disease with Rett like onset described in the literature, which developed typical vLINCL clinical phenotype after age 5.5 years. A short review of the literature showing NCL onset modalities is presented.


Assuntos
Proteínas de Membrana Transportadoras/genética , Lipofuscinoses Ceroides Neuronais/fisiopatologia , Síndrome de Rett/fisiopatologia , Idade de Início , Ataxia/etiologia , Cegueira/etiologia , Criança , Deficiências do Desenvolvimento/etiologia , Progressão da Doença , Eletroencefalografia , Feminino , Heterozigoto , Humanos , Lisossomos/metabolismo , Imagem por Ressonância Magnética , Mutação/genética , Pais , Convulsões/etiologia
17.
J Appl Genet ; 56(1): 49-56, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25204757

RESUMO

Epilepsy in females with mental retardation (EFMR) is a rare early infantile epileptic encephalopathy (EIEE), phenotypically resembling Dravet syndrome (DS). It is characterised by a variable degree of intellectual deficits and epilepsy. EFMR is caused by heterozygous mutations in the PCDH19 gene (locus Xq22.1) encoding protocadherin-19, a protein that is highly expressed during brain development. The protein is involved in cell adhesion and probably plays an important role in neuronal migration and formation of synaptic connections. EFMR is considered X-linked of variable mutations' penetrance. Mutations in the PCDH19 gene mainly arise de novo, but if inherited, they show a unique pattern of transmission. Females with heterozygous mutations are affected, while hemizygous males are not, regardless of mutation carriage. This singular mode might be explained by cell interference as a pathogenic molecular mechanism leading to neuronal dysfunction. Recently, PCDH19-related EIEE turned out to be more frequent than initially thought, contributing to around 16% of cases (25% in female groups) in the SCN1A-negative DS-like patients. Therefore, the PCDH19 gene is now estimated to be the second, after SCN1A, most clinically relevant gene in epilepsy.


Assuntos
Síndrome de Aicardi/genética , Epilepsia/genética , Padrões de Herança , Deficiência Intelectual/genética , Espasmos Infantis/genética , Caderinas/genética , Feminino , Humanos , Masculino , Linhagem
18.
Neurol Neurochir Pol ; 48(4): 254-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25168324

RESUMO

Mutations localized in THAP1 gene, locus 18p11.21 have been reported as causative of primary dystonia type 6 (DYT6). Disease which is characterized mainly by focal dystonia, frequently involving the craniocervical region, however associated also with early-onset generalized dystonia and spasmodic dysphonia. Here we report a novel mutation in the THAP1 gene identified in a Polish family with DYT6 phenotype - the c.15C>G substitution in exon 1 introducing the missense mutation p.Cys5Trp within the N-terminal THAP domain. The mutation was described in two generations, in patients showing a broad spectrum of focal and generalized dystonia symptoms of variable onset. Our results indicate that certain mutations in the THAP1 gene may lead to primary dystonia with remarkable intrafamilial clinical variability.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Proteínas de Ligação a DNA/genética , Distúrbios Distônicos/genética , Proteínas Nucleares/genética , Mutação Puntual , Saúde da Família , Feminino , Variação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Polônia
19.
Dev Period Med ; 18(4): 426-31, 2014 Oct-Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25874779

RESUMO

UNLABELLED: Diseases caused by mutations in SCN1A are currently named Genetic Epilepsies with Febrile Seizures Plus, and this term stands for expanded spectrum of syndrome previously called as GEFS+ (Generalized Epilepsy with Febrile Seizures Plus). SCN1A is the uniquely identified gene directly linked to specific type of epilepsy, and its testing has been included in the screening processes. THE AIM: To diagnose and describe epileptic syndromes caused by SCN1A mutations. MATERIAL AND METHODS: 203 patients were included in the screening process with suspected SCN1A mutation, based on clinical features and family history. Study group was selected based on inclusion and exclusion criteria and then preliminary epilepsy diagnosis was verified using ILAE classification. Molecular testing to screen SCN1A mutations was performed in the study group. RESULTS: Mutations were detected in 57 cases. Majority of patients (50 cases - 87.5%) suffered from Dravet syndrome, 8.8% (5 cases) were diagnosed as GEFS+, 3% as vaccines encephalopathy and Panayotopoulous syndrome. Mutations were not detected in children with isolated febrile seizures, family febrile seizures nor in patients with myoclonic - astatic epilepsy. CONCLUSIONS: Frequency of mutations in SCN1A in Dravet syndrome and GEFS+ in Polish populations are similar to other countries. Diagnostic clinical criteria are currently insufficient to draw precise diagnosis. There is a strong need to establish clinical criteria for molecular testing and this topic will be investigated in the future.


Assuntos
Epilepsias Mioclônicas/genética , Epilepsia Generalizada/genética , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Convulsões Febris/genética , Adolescente , Criança , Pré-Escolar , Análise Mutacional de DNA/métodos , Feminino , Variação Genética , Humanos , Lactente , Recém-Nascido , Masculino , Mutação de Sentido Incorreto/genética , Fenótipo , Polônia
20.
Am J Hum Genet ; 93(5): 967-75, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24207121

RESUMO

Dravet syndrome is a severe epilepsy syndrome characterized by infantile onset of therapy-resistant, fever-sensitive seizures followed by cognitive decline. Mutations in SCN1A explain about 75% of cases with Dravet syndrome; 90% of these mutations arise de novo. We studied a cohort of nine Dravet-syndrome-affected individuals without an SCN1A mutation (these included some atypical cases with onset at up to 2 years of age) by using whole-exome sequencing in proband-parent trios. In two individuals, we identified a de novo loss-of-function mutation in CHD2 (encoding chromodomain helicase DNA binding protein 2). A third CHD2 mutation was identified in an epileptic proband of a second (stage 2) cohort. All three individuals with a CHD2 mutation had intellectual disability and fever-sensitive generalized seizures, as well as prominent myoclonic seizures starting in the second year of life or later. To explore the functional relevance of CHD2 haploinsufficiency in an in vivo model system, we knocked down chd2 in zebrafish by using targeted morpholino antisense oligomers. chd2-knockdown larvae exhibited altered locomotor activity, and the epileptic nature of this seizure-like behavior was confirmed by field-potential recordings that revealed epileptiform discharges similar to seizures in affected persons. Both altered locomotor activity and epileptiform discharges were absent in appropriate control larvae. Our study provides evidence that de novo loss-of-function mutations in CHD2 are a cause of epileptic encephalopathy with generalized seizures.


Assuntos
Proteínas de Ligação a DNA/genética , Epilepsias Mioclônicas/genética , Animais , Criança , Transtornos Cognitivos/genética , Transtornos Cognitivos/patologia , Estudos de Coortes , Epilepsias Mioclônicas/patologia , Exoma , Feminino , Técnicas de Silenciamento de Genes , Haploinsuficiência , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Larva/genética , Masculino , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Fenótipo , Convulsões Febris/genética , Convulsões Febris/patologia , Adulto Jovem , Peixe-Zebra
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