SEARCH · PubMed Health

Results for “Neurodevelopmental Disorders”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources

PubMed2005

Mirror symmetric topographic maps can arise from activity-dependent synaptic changes.

Multiple adjacent, roughly mirror-image topographic maps are commonly observed in the sensory neocortex of many species. The cortical regions occupied by these maps are generally believed to be determined initially by genetically controlled chemical markers during development, with thalamocortical afferent activity subsequently exerting a progressively increasing influence over time. Here we use a computational model to show that adjacent topographic maps with mirror-image symmetry can arise from activity-dependent synaptic changes whenever the distribution radius of afferents sufficiently exceeds that of horizontal intracortical interactions. Which map edges become adjacent is strongly influenced by the probability distribution of input stimuli during map formation. Our results suggest that activity-dependent synaptic changes may play a role in influencing how adjacent maps become oriented following the initial establishment of cortical areas via genetically determined chemical markers. Further, the model unexpectedly predicts the occasional occurrence of adjacent maps with a different rotational symmetry. We speculate that such atypically oriented maps, in the context of otherwise normally interconnected cortical regions, might contribute to abnormal cortical information processing in some neurodevelopmental disorders.

Action Potentials↗

PubMed2006

Saccade adaptation in Williams-Beuren Syndrome.

PURPOSE: To investigate the capacity for rapid saccade adaptation in Williams-Beuren Syndrome (WBS), a genetic neurodevelopmental disorder, in which it has been observed that saccadic accuracy is severely reduced. METHODS: Saccade amplitude modification was elicited by backward steps (30% of target eccentricity) during the primary saccade in a classic saccade-adaptation paradigm. RESULTS: Patients with WBS showed a significant decrease in saccade amplitude. Furthermore, we observed that higher saccade accuracy before adaptation was related to more adaptation. CONCLUSIONS: The increased variability in motor performance does not abolish the ability for saccadic adaptation in subjects with WBS. Our results are congruent with the notion that part of the behavioral deficits observed in WBS may have a cerebellar origin.

Adaptation, Ocular↗

PubMed2026

A dual-reporter mouse for therapeutic discovery in Angelman syndrome.

Angelman syndrome is a neurodevelopmental disorder caused by loss of the maternal UBE3A allele, the sole source of UBE3A in mature neurons owing to epigenetic silencing of the paternal allele. Although emerging therapies are being developed to restore UBE3A expression by activating the dormant paternal UBE3A allele, existing mouse models for such preclinical studies have limited throughput and utility, creating bottlenecks for both in vitro therapeutic screening and in vivo characterization. To address this, we developed the Ube3a-INSG dual-reporter knockin mouse, in which an IRES-Nanoluciferase-T2A-Sun1-sfGFP (INSG) cassette was inserted downstream of the endogenous Ube3a stop codon. The INSG model preserves UBE3A protein levels and function while enabling 2 complementary allele-specific readouts: Sun1-sfGFP and Nanoluciferase. We show that Sun1-sfGFP, a nuclear envelope-localized reporter, enables single-cell fluorescence analysis, whole-brain light-sheet imaging, and nuclear quantification by flow cytometry. Further, Nanoluciferase supports high-throughput luminescence assays for sensitive pharmacological profiling in cultured neurons and noninvasive in vivo bioluminescence imaging for pharmacodynamic assessment. By combining scalable screening, cellular analysis, and real-time in vivo monitoring in a single model, the Ube3a-INSG dual-reporter mouse provides a powerful platform to accelerate therapeutic development centered on UBE3A.

Animals↗

PubMed1995

The genetic and functional basis of purine nucleotide feedback-resistant phosphoribosylpyrophosphate synthetase superactivity.

The genetic and functional basis of phosphoribosylpyrophosphate synthetase (PRS) superactivity associated with purine nucleotide inhibitor-resistance was studied in six families with this X chromosome-linked purine metabolic and neurodevelopmental disorder. Cloning and sequencing of PRS1 and PRS2 cDNAs, derived from fibroblast total RNA of affected male patients by reverse transcription and PCR amplification, demonstrated that each PRS1 cDNA contained a distinctive single base substitution predicting a corresponding amino acid substitution in the PRS1 isoform. Overall, the array of substitutions encompassed a substantial portion of the translated sequence of PRS1 cDNA. Plasmid-mediated expression of variant PRS1 cDNAs in Escherichia coli BL21 (DE3/pLysS) yielded recombinant mutant PRS1s, which, in each case, displayed a pattern and magnitude of purine nucleoside diphosphate inhibitor-resistance comparable to that found in cells of the respective patient. Kinetic analysis of recombinant mutant PRS1s showed that widely dispersed point mutations in the X chromosome-linked PRPS1 gene encoding the PRS1 isoform result in alteration of the allosteric mechanisms regulating both enzyme inhibition by purine nucleotides and activation by inorganic phosphate. The functional consequences of these mutations provide a tenable basis for the enhanced production of phosphoribosylpyrophosphate, purine nucleotides, and uric acid that are the biochemical hallmarks of PRS superactivity.

Base Sequence↗

PubMed2006

Expression of the human PAC1 receptor leads to dose-dependent hydrocephalus-related abnormalities in mice.

Hydrocephalus is a common and potentially devastating birth defect affecting the CNS, and its relationship with G protein-coupled receptors (GPCRs) is unknown. We have expressed 2, 4, or 6 copies of a GPCR--the human PAC1 receptor with a 130-kb transgene in the mouse nervous system in a pattern closely resembling that of the endogenous gene. Consistent with PAC1 actions, PKA and PKC activity were elevated in the brains of Tg mice. Remarkably, Tg mice developed dose-dependent hydrocephalus-like characteristics, including enlarged third and lateral ventricles and reduced cerebral cortex, corpus callosum, and subcommissural organ (SCO). Neuronal proliferation and apoptosis were implicated in hydrocephalus, and we observed significantly reduced neuronal proliferation and massively increased neuronal apoptosis in the developing cortex and SCO of Tg embryos, while neurite outgrowth and neuronal migration in vitro remain uncompromised. Ventricular ependymal cilia are crucial for directing cerebrospinal fluid flow, and ependyma of Tg mice exhibited disrupted cilia with increased phospho-CREB immunoreactivity. These data demonstrate that altered neuronal proliferation/apoptosis and disrupted ependymal cilia are the main factors contributing to hydrocephalus in PAC1-overexpressing mice. This is the first report to our knowledge demonstrating that misregulation of GPCRs can be involved in hydrocephalus-related neurodevelopmental disorders.

Animals↗

PubMed1999

Accumulation of macrophages in the CSF of schizophrenic patients during acute psychotic episodes.

OBJECTIVE: There have been numerous reports of organic or structural abnormalities in the central nervous system (CNS) of patients with schizophrenia. Given that pathological conditions in the CNS are frequently reflected in the cell profiles of CSF, the authors compared the cytology of CSF from schizophrenic patients with that from a reference population in order to find out trails of elementary pathogenetic events in this serious psychiatric disease. METHOD: CSF samples from 35 patients with acute schizophrenia and 46 comparison subjects were prepared by Millipore filtration. The total and differential counts of CSF mononuclear cells were performed by light microscopy. RESULTS: At the beginning of treatment, the proportion of mononuclear phagocytes/macrophages in the patients' CSF was significantly higher than that in the comparison subjects. During treatment with conventional neuroleptic medication, the cytology returned to normal in several patients. CONCLUSIONS: The high proportion of macrophages in schizophrenia without a significantly higher total cell count may reflect neurodevelopmental disorder, a neurodegenerative process, or subtle CNS immunoactivation with mobilization of microglia.

Acute Disease↗

PubMed2003

Distribution of microtubule-associated protein MAP2-immunoreactive interstitial neurons in the parahippocampal white matter in subjects with schizophrenia.

OBJECTIVE: Evidence suggests that schizophrenia is a neurodevelopmental disorder that may involve abnormal connectivity between various cortical and subcortical brain areas. The parahippocampal gyrus is an area important for higher cognition in which a variety of cytoarchitectural, neuronal morphometric, and innervation abnormalities in schizophrenia have been reported. Previous studies have reported abnormal distributions of interstitial white matter neurons in prefrontal, parietal, and temporal neocortices, which suggests that schizophrenia may be related to prenatal disturbances in the cortical subplate, a transitory structure involved in the formation of connections in the developing cortex from which the interstitial white matter neurons derive. Abnormalities in the distribution of interstitial white matter neurons in the parahippocampal gyrus in schizophrenia may indicate an alteration in the migration of subplate neurons or in the pattern of programmed cell death that could lead to defective cortical circuitry and impaired cognition. METHOD: The authors used a monoclonal antibody against the microtubule-associated protein MAP2 to label interstitial white matter neurons in the anterior region of the parahippocampal gyrus from 41 individuals with schizophrenia and 15 comparison subjects. The distribution of MAP2-labeled neurons in relation to the gray matter/white matter boundary was determined by computer-assisted microscopy. RESULTS: The number of interstitial white matter neurons decreased with increasing white matter depth in both groups, but significantly more slowly in the schizophrenia group, with interstitial white matter neurons located deeper in white matter in schizophrenia subjects. CONCLUSIONS: These findings indicate there is an abnormality in the residua of the cortical subplate in the anterior region of the adult parahippocampal gyrus in schizophrenia subjects.

Adult↗

PubMed2005

Confirmation of association between autism and the mitochondrial aspartate/glutamate carrier SLC25A12 gene on chromosome 2q31.

OBJECTIVE: Autism is a neurodevelopmental disorder with childhood onset and a known major genetic component. A recent study identified a highly significant association between autism and a two-single-nucleotide-polymorphism haplotype in the SLC25A12 gene, with a homozygote genotype relative risk between 2.4 and 4.8. The authors' goal was to investigate this association with autism in Irish affected child-parent trios because replication in an independent sample is essential in the validation of such potentially important findings. METHOD: Markers rs2056202 and rs2292813 were genotyped in a total of 158 trios (442 individuals). The Transmission Disequilibrium Test was used to examine these markers for association with autism. RESULTS: In agreement with the recent study, the authors found significant association between autism and the C alleles of both rs2056202 and rs2292813 as well as the two-marker haplotype. CONCLUSIONS: These findings provide replication of the association between autism and SLC25A12.

Adult↗

PubMed2005

Trends in diagnosis rates for autism and ADHD at hospital discharge in the context of other psychiatric diagnoses.

OBJECTIVE: Concerns have been raised over observed increases in the number of children who are given a diagnosis of a neurodevelopmental disorder. The goal of this study was to examine trends by age and calendar year in the diagnosis of two of these disorders, autism and attention-deficit hyperactivity disorder (ADHD), in the context of other psychiatric disorders in a sample of hospitalized children. METHODS: Data from the Healthcare Cost and Utilization Project (HCUP) were used for descriptive analyses of secular trends of diagnosed psychiatric disorders between 1989 and 2000. Changes over time in rates of diagnosis of autism, ADHD, affective disorders, and substance-related disorders were examined and compared. RESULTS: Substance-related disorders were the most common mental disorders recorded at hospital discharge and increased by 39 percent between 1989 and 2000. Affective disorder was the next most common diagnosis and increased by 138 percent. Although autism and ADHD were far less common, their diagnosis rates nearly quadrupled over the course of the study. Although rates of diagnosis of affective and substance-related disorders generally increased over the lifespan, diagnosis of autism and ADHD followed a very different pattern, with peaks in rates at ages seven and 12. CONCLUSIONS: Increases in rates of diagnosis of etiologically unrelated mental disorders suggest that there have been changes in diagnostic practices over time, increases in community prevalence of these disorders, and increased likelihood of hospitalizations for different mental disorders.

Adolescent↗

PubMed2003

Preventing filicide in families with autistic children.

Autism is a complex neurodevelopmental disorder that affects social behaviors and parent-child interaction. It has been associated with an increased risk of social victimization, and a recent rise in number of acts of filicide of developmentally disabled children has included several cases of autism. In this article, possible risk factors for filicidal behavior in families with autistic children and prevention strategies are reviewed.

Adult↗

PubMed2002

Rett syndrome: clinical manifestations in males with MECP2 mutations.

Rett syndrome is a neurodevelopmental disorder characterized by cognitive and adaptive regression with autistic features, loss of acquired skills, and stereotypic hand movements that almost exclusively affects females. It is an X-linked dominant disorder, with presumed lethality in males. Nonetheless, there are a few descriptions of males suspected of having Rett syndrome. With the recent discovery that the MECP2 gene is responsible for most cases of Rett syndrome, it is possible to molecularly assess cases of affected males by direct sequencing analysis. We describe an Israeli family consisting of a female having classic Rett syndrome and a male sibling with severe neonatal encephalopathy. Molecular analysis revealed that both sister and brother have the same MECP2 gene mutation; however, their mother does not. This case, as well as other published studies of males with MECP2 mutations, reveals that the clinical manifestations in viable males vary from neonates with severe encephalopathy to adults with mental retardation and demonstrate genotype-phenotype correlations.

Abnormalities, Multiple↗

PubMed2002

Mutation analysis of MECP2 and clinical characterization in Korean patients with Rett syndrome.

Rett syndrome is a progressive neurodevelopmental disorder occurring predominantly in females. Recently, mutations in the MECP2 gene on Xq28, which encodes methyl-CpG binding protein 2, were identified as responsible for some cases of Rett syndrome. In the present study, we analyzed the entire coding sequence of the MECP2 gene in 20 sporadic cases of Rett syndrome in Korea. Of the 20 patients, 14 (70%) had pathogenic mutations, which included 10 different mutations. Altogether, there were five missense mutations (D97Y, L100V, R133C, T158M, R306C), four nonsense mutations (R168X, R255X, R270X, R294X), and one frameshift mutation (a 41-bp deletion at 1157-1197). Two of these were novel mutations (D97Y, L100V). Most of the nucleotide substitutions involved C to T transitions at CpG hotspots. We could find no clear phenotype-genotype correlation according to the type of mutation. However, there was a tendency for patients with no MECP2 mutation (30%) to show more severe symptoms and more rapid clinical progression than patients with mutations. Further studies are necessary to identify the other possible genetic causes of Rett syndrome.

Adolescent↗

PubMed2002

Rett syndrome phenotype following infantile acute encephalopathy.

Rett syndrome is a progressive neurodevelopmental disorder with a well-defined clinical spectrum and course. Recently, mutations in the gene encoding X-linked methyl-CpG binding protein 2 (MECP2) have been identified as the cause of Rett syndrome. Along with the classic form, variant forms of Rett syndrome and Rett syndrome phenotypes are also recognized. We report on a girl who, at age 2 months, developed an acute encephalopathy with destructive brain damage 12 hours after acellular pertussis vaccination. Peripheral lymphocyte subset analysis revealed the existence of T lymphocytes double positive for CD4 and CD8 markers. This pattern normalized over the following 3 months. Months later, the girl manifested a Rett syndrome phenotype. DNA screening of the MECP2 gene was unrevealing in the child and her parents. This previously unreported association emphasizes the notion that Rett syndrome phenotypes can result from different (either genetic or environmental) causes.

Acute Disease↗

PubMed2003

MECP2 and beyond: phenotype-genotype correlations in Rett syndrome.

The association of Rett syndrome with pathogenic mutations of the methyl-CpG binding protein 2 (MECP2) gene was first made in 1999. Since that time, it has been found that the clinical phenotype can, at least in part, be explained in terms of the type and location of the MECP2 mutation and epigenetic factors such as skewing of X-chromosome inactivation. In addition, MECP2 mutations may be associated with non-Rett syndrome clinical phenotypes, including nonsyndromic and syndromic X-linked mental retardation and Angelman-like phenotypes. Intense research efforts are currently focused on understanding the pathogenesis of Rett syndrome, using sophisticated techniques such as microarray analysis, and the development of mouse models, with an ultimate aim being the development of targeted therapies that could ameliorate or even prevent the devastating consequences of this enigmatic neurodevelopmental disorder.

Angelman Syndrome↗

PubMed2004

Effect of topiramate on seizures and respiratory dysrhythmia in Rett syndrome.

Rett syndrome, a neurodevelopmental disorder, manifests in the first few years of life with developmental arrest, stereotyped behaviors, and respiratory abnormalities. Seizures occur in 70 to 80% of patients. Clinical drug trials have not demonstrated the superiority of any specific antiepilepsy drug. We report our experience with topiramate in eight patients with Rett syndrome. Topiramate was initiated as monotherapy in two patients and as adjunctive therapy in six patients. Seven patients had improved seizure control. Respiratory abnormalities improved by 50 to 75% in two patients and by 20 to 50% in two others. In our cohort, seven of eight patients showed improvement in seizure control and/or respiratory abnormalities on topiramate. Topiramate was well tolerated. The effect of topiramate, a broad-spectrum drug, could be due to its gamma-aminobutyric acid (GABA)ergic and glutaminergic effects, both systems thought to be disordered in Rett syndrome.

Adolescent↗

PubMed2005

Health service use in Rett syndrome.

Rett syndrome is a severe neurodevelopmental disorder affecting girls, caused by mutations in the MECP2 gene. There are no population-based data on the extent and determinants of health service use in this disorder. The population-based registry, the Australian Rett Syndrome database, was the source of phenotype data. This also contains data from mutation screening and X-inactivation studies. Data on retrospective (n = 152) and prospective (n = 162) health service use were collected in 2000 from a questionnaire and a calendar study, respectively. Health service use was highest in younger cases (P = .001) and lowest in cases with milder phenotypes (P < .001). Random X-inactivation was associated with service use (P = .02). Maternal education, phenotype, and individual mutations were determinants of health service use. The use of a retrospective and prospective data set enabled accurate assessment of service use in Rett syndrome. Both genetic and sociodemographic determinants of health service use were identified, with important implications for the optimal and equitable management of children with Rett syndrome.

Adolescent↗

PubMed2005

MECP2 abnormality phenotypes: clinicopathologic area with broad variability.

Rett syndrome is a neurodevelopmental disorder that occurs worldwide and predominantly affects girls. The MECP2 gene has been put forward as the underlying gene. Interestingly, other clinical presentations in addition to Rett syndrome have been reported to be the results of deviations in MECP2. This prompted us to outline a working hypothesis of how these diverse phenotypes are connected. Our aim was to summarize the clinical picture of deviations in MECP2 at this moment to obtain a comprehensive overview. Thus, we have attempted to create a gradient, starting at the left with the most severely affected MECP2-deviant subgroups, represented by boys who are diseased in the intrauterine phase or as neonates, and at the right, the most mildly affected subgroup, female asymptomatic carriers. In the center, with dominant numbers, we have placed classic Rett syndrome presentations, together with the late-onset Rett syndrome variant and preserved speech variant. In conclusion, we feel that it is important to emphasize that Rett syndrome is a strictly clinical diagnosis that is not identical to the far broader concept of MECP2 deviations.

Angelman Syndrome↗

PubMed2005

Neurophysiology of Rett syndrome.

Rett syndrome is a neurodevelopmental disorder that in most cases is consequent to a mutation in the MECP2 gene. The central nervous system is the primary organ system involved in Rett syndrome. Neurophysiologic evaluations provide information concerning the developmental aspects of Rett syndrome and the character and extent of involvement of the central, peripheral, and autonomic nervous system pathways. Evoked potentials typically demonstrate intactness of peripheral auditory and visual pathways and suggest dysfunction of central or "higher" cortical pathways. Somatosensory evoked potentials can be characterized by "giant" responses, suggesting cortical hyperexcitability. Cortical hyperexcitability is further suggested by the findings of the electroencephalogram (EEG), which are primarily characterized by a loss of expected developmental features; the appearance of focal, multifocal, and generalized epileptiform abnormalities; and the occurrence of rhythmic slow (theta) activity, primarily in the frontal-central regions. Epileptic seizures are reported to occur frequently in Rett syndrome. However, many events presumed to be seizures have no EEG correlate during video-EEG monitoring. Impairment of the autonomic nervous system in Rett syndrome is suggested by an increased incidence of long Q-T intervals during electrocardiographic recordings and diminished heart rate variability. Autonomic nervous system dysfunction can contribute to the increased incidence of sudden unexpected death in Rett syndrome.

Afferent Pathways↗