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1.
Sci Adv ; 5(9): eaax2166, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31579823

RESUMO

RNA binding proteins are key players in posttranscriptional regulation and have been implicated in neurodevelopmental and neuropsychiatric disorders. Here, we report a significant burden of heterozygous, likely gene-disrupting variants in CSDE1 (encoding a highly constrained RNA binding protein) among patients with autism and related neurodevelopmental disabilities. Analysis of 17 patients identifies common phenotypes including autism, intellectual disability, language and motor delay, seizures, macrocephaly, and variable ocular abnormalities. HITS-CLIP revealed that Csde1-binding targets are enriched in autism-associated gene sets, especially FMRP targets, and in neuronal development and synaptic plasticity-related pathways. Csde1 knockdown in primary mouse cortical neurons leads to an overgrowth of the neurites and abnormal dendritic spine morphology/synapse formation and impaired synaptic transmission, whereas mutant and knockdown experiments in Drosophila result in defects in synapse growth and synaptic transmission. Our study defines a new autism-related syndrome and highlights the functional role of CSDE1 in synapse development and synaptic transmission.

2.
J Pediatr ; 215: 158-163.e6, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31587863

RESUMO

OBJECTIVE: To examine the symptomatology and treatment of Sturge-Weber syndrome (SWS) from a large patient registry to identify common symptoms, clinical outcomes, and areas of unmet clinical need. STUDY DESIGN: An online patient questionnaire was completed by 628 patients with clinically diagnosed SWS and/or a port-wine birthmark over a 19-year period. Statistical analysis focused on seizures as a primary outcome measure, as well as associated neurologic, ophthalmologic, and dermatologic attributes to understand some of the natural history of the disorder. RESULTS: The majority (92%) of patients had a port-wine birthmark, and 60% of the patients had neurologic symptoms, including seizures and stroke-like episodes. Glaucoma was present in 48% of the patients. Other common symptoms included behavioral (46%) and hearing (or vestibular) disorders (24%). Delayed diagnosis of SWS beyond 1 year after presentation of initial symptoms occurred in 16% of the patients, with 68% having clear preexisting comorbidities, especially headaches. Birthmarks on the forehead and scalp were associated with seizures (P < .001), whereas bilaterality of birthmarks was not. Only 49% of patients being treated for epilepsy were free of seizures. CONCLUSIONS: Seizures and glaucoma were the primary drivers for a diagnosis of SWS in patients with delayed diagnosis, and hearing (or vestibular) and behavioral problems were also prevalent. The diagnosis of SWS was delayed when the predominant symptom was headache. Seizure control was quite poor in many patients with SWS. Our findings highlight an important need for detailed, longitudinal data to improve our understanding of SWS and develop better treatment strategies for patients with this disorder.

3.
Schizophr Res ; 210: 149-156, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31204062

RESUMO

DISC1 was originally expected to be a genetic risk factor for schizophrenia, but the genome wide association studies have not supported this idea. In contrast, neurobiological studies of DISC1 in cell and animal models have demonstrated that direct perturbation of DISC1 protein elicits neurobiological and behavioral abnormalities relevant to a wide range of psychiatric conditions, in particular psychosis. Thus, the utility of DISC1 as a biological lead for psychosis research is clear. In the present study, we aimed to capture changes in the molecular landscape in the prefrontal cortex upon perturbation of DISC1, using the Disc1 locus impairment (Disc1-LI) model in which the majority of Disc1 isoforms have been depleted, and to explore potential molecular mediators relevant to psychiatric conditions. We observed a robust change in gene expression profile elicited by Disc1-LI in which the stronger effects on molecular networks were observed in early stage compared with those in adulthood. Significant alterations were found in specific pathways relevant to psychiatric conditions, such as pathways of signaling by G protein-coupled receptor, neurotransmitter release cycle, and voltage gated potassium channels. The differentially expressed genes (DEGs) between Disc1-LI and wild-type mice are significantly enriched not only in neurons, but also in astrocytes and oligodendrocyte precursor cells. The brain-disorder-associated genes at the mRNA and protein levels rather than those at the genomic levels are enriched in the DEGs. Together, our present study supports the utility of Disc1-LI mice in biological research for psychiatric disorder-associated molecular networks.

4.
Am J Psychiatry ; 176(9): 730-743, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31055969

RESUMO

OBJECTIVE: The mechanisms leading to schizophrenia are likely to be diverse. However, there may be common pathophysiological pathways for subtypes of the disease. The authors tested the hypothesis that increased protein insolubility and ubiquitination underlie the pathophysiology for a subtype of schizophrenia. METHODS: Prefrontal cortex and superior temporal gyrus from postmortem brains of individuals with and without schizophrenia were subjected to cold sarkosyl fractionation, separating proteins into soluble and insoluble fractions. Protein insolubility and ubiquitin levels were quantified for each insoluble fraction, with normalization to total homogenate protein. Mass spectrometry analysis was then performed to identify the protein contents of the insoluble fractions. The potential biological relevance of the detected proteins was assessed using Gene Ontology enrichment analysis and Ingenuity Pathway Analysis. RESULTS: A subset of the schizophrenia brains showed an increase in protein insolubility and ubiquitination in the insoluble fraction. Mass spectrometry of the insoluble fraction revealed that brains with increased insolubility and ubiquitination exhibited a similar peptide expression by principal component analysis. The proteins that were significantly altered in the insoluble fraction were enriched for pathways relating to axon target recognition as well as nervous system development and function. CONCLUSIONS: This study suggests a pathological process related to protein insolubility for a subset of patients with schizophrenia. Determining the molecular mechanism of this subtype of schizophrenia could lead to a better understanding of the pathways underlying the clinical phenotype in some patients with major mental illness as well as to improved nosology and identification of novel therapeutic targets.

5.
Lancet ; 393(10179): 1465-1472, 2019 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-30967217

RESUMO

Leonardo da Vinci (1452-1519) contributed to the study of the nervous system. His earliest surviving anatomical drawings (circa 1485-93) included studies of the skull, brain, and cerebral ventricles. These works reflected his efforts to understand medieval psychology, including the localisation of sensory and motor functions to the brain. He was also the first to pith a frog, concluding that piercing the spinal medulla causes immediate death. After a 10-year interval in the early 1500s Leonardo resumed his anatomical studies and developed a method to inject hot wax into the ventricular system, creating a cast that showed the shape and extent of the ventricles. During this period he also progressed in his understanding of the anatomy of the cranial nerves. Besides being the first to identify the olfactory nerve as a cranial nerve, his dissections showed him that contrary to previous theories, the nerves do not converge on the lateral or third ventricles. Leonardo also performed detailed studies of the peripheral nervous system. Although his discoveries had little influence on the development of the field of anatomy, they represent an astonishingly sharp break from the field that had seen little if any progress in the previous 13 centuries. His work reflects the emergence of the modern scientific era and forms a key part of his integrative approach to art and science.


Assuntos
Anatomia/história , Encéfalo/anatomia & histologia , Pessoas Famosas , Ilustração Médica/história , História do Século XV , História do Século XVI
6.
Pediatr Neurol ; 96: 30-36, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30853154

RESUMO

BACKGROUND: Sturge-Weber syndrome (SWS) is caused by a somatic mutation in GNAQ leading to capillary venous malformations in the brain presenting with various neurological, ophthalmic, and cognitive symptoms of variable severity. This clinical variability makes accurate prognosis difficult. We hypothesized that the greater extent of physical factors (extent of skin, eye, and brain involvement), presence of possible genetic factors (gender and family history), and age of seizure onset may be associated with greater symptom severity and need for surgery in patients with SWS. METHODS: The questionnaire was collected from 277 participants (age: two months to 66 years) with SWS brain involvement at seven US sites. RESULTS: Bilateral brain involvement was associated with both learning disorder and intellectual disability, whereas port-wine birthmark extent was associated with epilepsy and an increased likelihood of glaucoma surgery. Subjects with family history of vascular birthmarks were also more likely to report symptomatic strokes, and family history of seizures was associated with earlier seizure onset. Learning disorder, intellectual disability, strokelike episodes, symptomatic stroke, hemiparesis, visual field deficit, and brain surgery were all significantly associated with earlier onset of seizures. CONCLUSION: The extent of brain and skin involvement in SWS, as well as the age of seizure onset, affect prognosis. Other genetic factors, particularly variants involved in vascular development and epilepsy, may also contribute to neurological prognosis, and further study is needed.

7.
Genome Res ; 29(4): 646-656, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30846530

RESUMO

We report on the development of a methylation analysis workflow for optical detection of fluorescent methylation profiles along chromosomal DNA molecules. In combination with Bionano Genomics genome mapping technology, these profiles provide a hybrid genetic/epigenetic genome-wide map composed of DNA molecules spanning hundreds of kilobase pairs. The method provides kilobase pair-scale genomic methylation patterns comparable to whole-genome bisulfite sequencing (WGBS) along genes and regulatory elements. These long single-molecule reads allow for methylation variation calling and analysis of large structural aberrations such as pathogenic macrosatellite arrays not accessible to single-cell second-generation sequencing. The method is applied here to study facioscapulohumeral muscular dystrophy (FSHD), simultaneously recording the haplotype, copy number, and methylation status of the disease-associated, highly repetitive locus on Chromosome 4q.


Assuntos
Metilação de DNA , Análise de Sequência de DNA/métodos , Variação Genética , Humanos , Distrofia Muscular Facioescapuloumeral/genética , Análise de Sequência de DNA/normas
8.
Biol Psychiatry ; 2018 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-30219209

RESUMO

BACKGROUND: Although several studies have linked adolescent cannabis use to long-term cognitive dysfunction, there are negative reports as well. The fact that not all users develop cognitive impairment suggests a genetic vulnerability to adverse effects of cannabis, which are attributed to action of Δ9-tetrahydrocannabinol (Δ9-THC), a cannabis constituent and partial agonist of brain cannabinoid receptor 1. As both neurons and glial cells express cannabinoid receptor 1, genetic vulnerability could influence Δ9-THC-induced signaling in a cell type-specific manner. METHODS: Here we use an animal model of inducible expression of dominant-negative disrupted in schizophrenia 1 (DN-DISC1) selectively in astrocytes to evaluate the molecular mechanisms, whereby an astrocyte genetic vulnerability could interact with adolescent Δ9-THC exposure to impair recognition memory in adulthood. RESULTS: Selective expression of DN-DISC1 in astrocytes and adolescent treatment with Δ9-THC synergistically affected recognition memory in adult mice. Similar deficits in recognition memory were observed following knockdown of endogenous Disc1 in hippocampal astrocytes in mice treated with Δ9-THC during adolescence. At the molecular level, DN-DISC1 and Δ9-THC synergistically activated the nuclear factor-κB-cyclooxygenase-2 pathway in astrocytes and decreased immunoreactivity of parvalbumin-positive presynaptic inhibitory boutons around pyramidal neurons of the hippocampal CA3 area. The cognitive abnormalities were prevented in DN-DISC1 mice exposed to Δ9-THC by simultaneous adolescent treatment with the cyclooxygenase-2 inhibitor, NS398. CONCLUSIONS: Our data demonstrate that individual vulnerability to cannabis can be exclusively mediated by astrocytes. Results of this work suggest that genetic predisposition within astrocytes can exaggerate Δ9-THC-produced cognitive impairments via convergent inflammatory signaling, suggesting possible targets for preventing adverse effects of cannabis within susceptible individuals.

9.
BMC Res Notes ; 11(1): 558, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-30075799

RESUMO

OBJECTIVE: Lymphoblastoid cell lines are widely used in genetic and genomic studies. Previous work has characterized variant stability in transformed culture and across culture passages. Our objective was to extend this work to evaluate single nucleotide polymorphism and structural variation across cell line expansions, which are commonly used in biorepository distribution. Our study used DNA and cell lines sampled from six research participants. We assayed genome-wide genetic variants and inferred structural variants for DNA extracted from blood, from transformed cell cultures, and from three generations of expansions. RESULTS: Single nucleotide variation was stable between DNA and expanded cell lines (ranging from 99.90 to 99.98% concordance). Structural variation was less consistent across expansions (median 33% concordance) with a noticeable decrease in later expansions. In summary, we demonstrate consistency between SNPs assayed from whole blood DNA and LCL DNA; however, more caution should be taken in using LCL DNA to study structural variation.

10.
Sci Rep ; 8(1): 8764, 2018 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-29884813

RESUMO

The Kryptopterus bicirrhis (glass catfish) is known to respond to electromagnetic fields (EMF). Here we tested its avoidance behavior in response to static and alternating magnetic fields stimulation. Using expression cloning we identified an electromagnetic perceptive gene (EPG) from the K. bicirrhis encoding a protein that responds to EMF. This EPG gene was cloned and expressed in mammalian cells, neuronal cultures and in rat's brain. Immunohistochemistry showed that the expression of EPG is confined to the mammalian cell membrane. Calcium imaging in mammalian cells and cultured neurons expressing EPG demonstrated that remote activation by EMF significantly increases intracellular calcium concentrations, indicative of cellular excitability. Moreover, wireless magnetic activation of EPG in rat motor cortex induced motor evoked responses of the contralateral forelimb in vivo. Here we report on the development of a new technology for remote, non-invasive modulation of cell function.

11.
Am J Med Genet A ; 173(9): 2505-2510, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28650581

RESUMO

Pathogenic variants in the mitochondrial aminoacyl tRNA synthetases lead to deficiencies in mitochondrial protein synthesis and are associated with a broad range of clinical presentations usually with early onset and inherited in an autosomal recessive manner. Of the 19 mitochondrial aminoacyl tRNA synthetases, WARS2, encoding mitochondrial tryptophanyl tRNA synthetase, was as of late the only one that had not been associated with disease in humans. A case of a family with pathogenic variants in WARS2 that caused mainly intellectual disability, speech impairment, aggressiveness, and athetosis was recently reported. Here we substantially extend and consolidate the symptomatology of WARS2 by presenting a patient with severe infantile-onset leukoencephalopathy, profound intellectual disability, spastic quadriplegia, epilepsy, microcephaly, short stature, failure to thrive, cerebral atrophy, and periventricular white matter abnormalities. He was found by whole-exome sequencing to have compound heterozygous variants in WARS2, c.938A>T (p.K313M) and c.298_300delCTT (p.L100del). De novo synthesis of proteins inside mitochondria was reduced in the patient's fibroblasts, leading to significantly lower steady-state levels of respiratory chain subunits compared to control and resulting in lower oxygen consumption rates.


Assuntos
Deficiência Intelectual/genética , Leucoencefalopatias/genética , Quadriplegia/genética , Triptofano-tRNA Ligase/genética , Idade de Início , Sequência de Aminoácidos/genética , Humanos , Lactente , Deficiência Intelectual/fisiopatologia , Leucoencefalopatias/fisiopatologia , Masculino , Microcefalia , Mitocôndrias/genética , Mutação , Quadriplegia/fisiopatologia , Patologia da Fala e Linguagem , Adulto Jovem
12.
Science ; 356(6336)2017 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-28450582

RESUMO

Neuropsychiatric disorders have a complex genetic architecture. Human genetic population-based studies have identified numerous heritable sequence and structural genomic variants associated with susceptibility to neuropsychiatric disease. However, these germline variants do not fully account for disease risk. During brain development, progenitor cells undergo billions of cell divisions to generate the ~80 billion neurons in the brain. The failure to accurately repair DNA damage arising during replication, transcription, and cellular metabolism amid this dramatic cellular expansion can lead to somatic mutations. Somatic mutations that alter subsets of neuronal transcriptomes and proteomes can, in turn, affect cell proliferation and survival and lead to neurodevelopmental disorders. The long life span of individual neurons and the direct relationship between neural circuits and behavior suggest that somatic mutations in small populations of neurons can significantly affect individual neurodevelopment. The Brain Somatic Mosaicism Network has been founded to study somatic mosaicism both in neurotypical human brains and in the context of complex neuropsychiatric disorders.


Assuntos
Encéfalo/anormalidades , Transtornos Mentais/genética , Mosaicismo , Doenças do Sistema Nervoso/genética , Células-Tronco Neurais/fisiologia , Neurônios/fisiologia , Encéfalo/metabolismo , Divisão Celular/genética , Dano ao DNA , Análise Mutacional de DNA/métodos , Reparo do DNA/genética , Replicação do DNA , Genoma Humano , Células Germinativas/metabolismo , Humanos , Rede Nervosa/crescimento & desenvolvimento , Rede Nervosa/metabolismo , Células-Tronco Neurais/metabolismo , Neurônios/metabolismo
13.
Schizophr Res ; 185: 58-66, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28038920

RESUMO

Clozapine is the only medication indicated for treating refractory schizophrenia, due to its superior efficacy among all antipsychotic agents, but its mechanism of action is poorly understood. To date, no studies of human postmortem brain have characterized the gene expression response to clozapine. Therefore, we addressed this question by analyzing expression data extracted from published microarray studies involving brains of patients on antipsychotic therapy. We first performed a systematic review and identified four microarray studies of postmortem brains from antipsychotic-treated patients, then extracted the expression data. We then performed generalized linear model analysis on each study separately, and identified the genes differentially expressed in response to clozapine compared to other atypical antipsychotic medications, as well as their associated canonical pathways. We also found a number of genes common to all four studies that we analyzed: GCLM, ZNF652, and GYPC. In addition, pathway analysis highlighted the following processes in all four studies: clathrin-mediated endocytosis, SAPK/JNK signaling, 3-phosphoinositide synthesis, and paxillin signaling. Our analysis yielded the first comprehensive compendium of genes and pathways differentially expressed upon clozapine treatment in the human brain, which may provide insight into the mechanism and unique efficacy of clozapine, as well as the pathophysiology of schizophrenia.


Assuntos
Antipsicóticos/uso terapêutico , Encéfalo/efeitos dos fármacos , Clozapina/uso terapêutico , Expressão Gênica/efeitos dos fármacos , Esquizofrenia , Transdução de Sinais/efeitos dos fármacos , Autopsia , Encéfalo/fisiopatologia , Bases de Dados Bibliográficas/estatística & dados numéricos , Feminino , Humanos , Masculino , Esquizofrenia/tratamento farmacológico , Esquizofrenia/patologia , Esquizofrenia/fisiopatologia , Transdução de Sinais/genética
14.
PLoS Genet ; 12(9): e1006245, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27632392

RESUMO

De novo mutation is highly implicated in autism spectrum disorder (ASD). However, the contribution of post-zygotic mutation to ASD is poorly characterized. We performed both exome sequencing of paired samples and analysis of de novo variants from whole-exome sequencing of 2,388 families. While we find little evidence for tissue-specific mosaic mutation, multi-tissue post-zygotic mutation (i.e. mosaicism) is frequent, with detectable mosaic variation comprising 5.4% of all de novo mutations. We identify three mosaic missense and likely-gene disrupting mutations in genes previously implicated in ASD (KMT2C, NCKAP1, and MYH10) in probands but none in siblings. We find a strong ascertainment bias for mosaic mutations in probands relative to their unaffected siblings (p = 0.003). We build a model of de novo variation incorporating mosaic variants and errors in classification of mosaic status and from this model we estimate that 33% of mosaic mutations in probands contribute to 5.1% of simplex ASD diagnoses (95% credible interval 1.3% to 8.9%). Our results indicate a contributory role for multi-tissue mosaic mutation in some individuals with an ASD diagnosis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Transtorno do Espectro Autista/genética , Proteínas de Ligação a DNA/genética , Mosaicismo , Cadeias Pesadas de Miosina/genética , Proteínas de Neoplasias/genética , Miosina não Muscular Tipo IIB/genética , Adolescente , Adulto , Transtorno do Espectro Autista/patologia , Criança , Pré-Escolar , Exoma/genética , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Especificidade de Órgãos/genética , Irmãos
15.
Transl Oncol ; 9(2): 124-129, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27084428

RESUMO

Protein microarray technology has been successfully used for identifying substrates of purified activated kinases. We used protein microarrays to globally interrogate the effects of PTEN and Akt activity on the phospho-kinome of in vitro and in vivo glioma models and validated results in clinical pathological specimens. Whole cell lysates extracted from tumor samples can be applied to human kinome chip microarrays to profile the global kinase phosphorylation patterns in a high-throughput manner and identify novel substrates inherent to the tumor cell and the interactions with tumor microenvironment. Our findings identify a novel microarray-based method for assessing intracellular signaling events applicable to human oncogenesis and other pathophysiologic states.

16.
PLoS One ; 11(3): e0149646, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26933844

RESUMO

Copy number variants (CNVs) were detected and analyzed in 14 probands with autism and intellectual disability with self-injurious behavior (SIB) resulting in tissue damage. For each proband we obtained a clinical history and detailed behavioral descriptions. Genetic anomalies were observed in all probands, and likely clinical significance could be established in four cases. This included two cases having novel, de novo copy number variants and two cases having variants likely to have functional significance. These cases included segmental trisomy 14, segmental monosomy 21, and variants predicted to disrupt the function of ZEB2 (encoding a transcription factor) and HTR2C (encoding a serotonin receptor). Our results identify variants in regions previously implicated in intellectual disability and suggest candidate genes that could contribute to the etiology of SIB.


Assuntos
Variações do Número de Cópias de DNA/genética , Predisposição Genética para Doença/genética , Comportamento Autodestrutivo/genética , Adolescente , Transtorno Autístico/genética , Criança , Cromossomos Humanos Par 14/genética , Cromossomos Humanos Par 21/genética , Feminino , Proteínas de Homeodomínio/genética , Humanos , Deficiência Intelectual/genética , Masculino , Monossomia/genética , Receptor 5-HT2C de Serotonina/genética , Proteínas Repressoras/genética , Trissomia/genética , Homeobox 2 de Ligação a E-box com Dedos de Zinco
17.
Genes (Basel) ; 5(4): 1064-94, 2014 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-25513881

RESUMO

Somatic mosaicism refers to the occurrence of two genetically distinct populations of cells within an individual, derived from a postzygotic mutation. In contrast to inherited mutations, somatic mosaic mutations may affect only a portion of the body and are not transmitted to progeny. These mutations affect varying genomic sizes ranging from single nucleotides to entire chromosomes and have been implicated in disease, most prominently cancer. The phenotypic consequences of somatic mosaicism are dependent upon many factors including the developmental time at which the mutation occurs, the areas of the body that are affected, and the pathophysiological effect(s) of the mutation. The advent of second-generation sequencing technologies has augmented existing array-based and cytogenetic approaches for the identification of somatic mutations. We outline the strengths and weaknesses of these techniques and highlight recent insights into the role of somatic mosaicism in causing cancer, neurodegenerative, monogenic, and complex disease.

18.
Am J Med Genet A ; 164A(11): 2914-21, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25124326

RESUMO

The γ-aminobutyric acid type A (GABAA ) receptor is one of the three main classes of receptors activated by GABA, the principal inhibitory neurotransmitter in the central nervous system. Mutations in genes encoding various subunits of this receptor (GABRA1, GABRA2, GABRA4, GABRA5, GABRA6, GABRB1, GABRB3, GABRG1, GABRG2, GABRG3, and GABRD) are implicated in a number of neurological and developmental disorders, including epilepsy and autism. To date, no human genetics studies have implicated mutations in GABRB2, encoding the ß2 subunit of the GABAA receptor, with neurodevelopmental disorders. Here we present a 12-year-old girl with intellectual disability and epilepsy, who was discovered by whole exome sequencing to have a de novo heterozygous missense variant in exon 4 of GABRB2 (c.236T>C; p.M79T). This variant is likely pathogenic, based on in silico analyses, as well as the fact that it results in the non-conservative substitution of a non-polar amino acid with a polar amino acid at a position that is evolutionarily conserved across multiple species. Our findings underscore the need for further investigation into the mechanisms by which mutations in GABRB2 contribute to neurological and developmental dysfunction.


Assuntos
Epilepsia/genética , Estudos de Associação Genética , Variação Genética , Deficiência Intelectual/genética , Receptores de GABA-A/genética , Sequência de Aminoácidos , Criança , Eletroencefalografia , Epilepsia/diagnóstico , Exoma , Feminino , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Deficiência Intelectual/diagnóstico , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Conformação Proteica , Receptores de GABA-A/química , Alinhamento de Sequência
19.
J Mol Diagn ; 16(5): 495-503, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25132481

RESUMO

Human identity testing is critical to the fields of forensics, paternity, and hematopoietic stem cell transplantation. Most bone marrow (BM) engraftment testing currently uses microsatellites or short tandem repeats that are resolved by capillary electrophoresis. Single-nucleotide polymorphisms (SNPs) are theoretically a better choice among polymorphic DNA; however, ultrasensitive detection of SNPs using next-generation sequencing is currently not possible because of its inherently high error rate. We circumvent this problem by analyzing blocks of closely spaced SNPs, or haplotypes. As proof-of-principle, we chose the HLA-A locus because it is highly polymorphic and is already genotyped to select proper donors for BM transplant recipients. We aligned common HLA-A alleles and identified a region containing 18 closely spaced SNPs, flanked by nonpolymorphic DNA for primer placement. Analysis of cell line mixtures shows that the assay is accurate and precise, and has a lower limit of detection of approximately 0.01%. The BM from a series of hematopoietic stem cell transplantation patients who tested as all donor by short tandem repeat analysis demonstrated 0% to 1.5% patient DNA. Comprehensive analysis of the human genome using the 1000 Genomes database identified many additional loci that could be used for this purpose. This assay may prove useful to identify hematopoietic stem cell transplantation patients destined to relapse, microchimerism associated with solid organ transplantation, forensic applications, and possibly patient identification.


Assuntos
DNA , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Alelos , Células da Medula Óssea , Linhagem Celular Tumoral , Biologia Computacional , Testes Genéticos/métodos , Testes Genéticos/normas , Genoma Humano , Antígenos HLA-A/genética , Sequenciamento de Nucleotídeos em Larga Escala/normas , Humanos , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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