Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tuberous sclerosis complex (TSC) is a tumor suppressor gene syndrome characterized by seizures, mental retardation, autism, and tumors of the brain, kidney, heart, retina, and skin. TSC is caused by mutations in either TSC1 or TSC2, both of which are tumor suppressor genes. Hamartin, the protein product of TSC1, was found to interact with the ezrin-radixin-moesin family of cytoskeletal proteins and to activate the small GTPase Rho. To determine whether tuberin, the TSC2 product, can also activate Rho, we stably expressed full-length human tuberin in two cell types: MDCK cells and ELT3 cells. ELT3 cells lack endogenous tuberin expression. We found that expression of human tuberin in both MDCK and ELT3 cells was associated with an increase in the amount of Rho-GTP, but not in Rac1-GTP or cdc42-GTP. Tuberin expression increased cell adhesion in both cell types, and decreased chemotactic cell migration in ELT3 cells. In MDCK cells, there was a decrease in the amount of total Focal Adhesion Kinase (FAK) and an increase in the fraction of phosphorylated FAK. These findings demonstrate for the first time that tuberin activates Rho and regulates cell adhesion and migration. Pathways involving Rho activation may have relevance to the clinical manifestations of TSC, including pulmonary lymphangioleiomyomatosis.
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PMID:Tuberin, the tuberous sclerosis complex 2 tumor suppressor gene product, regulates Rho activation, cell adhesion and migration. 1246 66

NRCAM (Neuronal Cell Adhesion Molecule) has an important role in axonal guidance and the organization of neural circuitry during brain development. Association analyses in human populations have identified NRCAM as a candidate gene for autism susceptibility. In the present study, we evaluated Nrcam-null mice for sociability, social novelty preference, and reversal learning as a model for the social deficits, repetitive behavior, and cognitive rigidity characteristic of autism. Prepulse inhibition of acoustic startle responses was also measured, to reflect sensorimotor-gating deficits in autism spectrum disorders. Assays for anxiety-like behavior in an elevated plus maze and open field, motor coordination, and olfactory ability in a buried food test were conducted to provide control measures for the interpretation of results. Overall, the loss of Nrcam led to behavioral alterations in sociability, acquisition of a spatial task, and reversal learning, dependent on sex. In comparison to male wild type mice, male Nrcam-null mutants had significantly decreased sociability in a three-chambered choice task. Low sociability in the male null mutants was not associated with changes in anxiety-like behavior, activity, or motor coordination. Male, but not female, Nrcam-null mice had small decreases in prepulse inhibition. Nrcam deficiency in female mice led to impaired acquisition of spatial learning in the Morris water maze task. Reversal learning deficits were observed in both male and female Nrcam-null mice. These results provide evidence that NRCAM mediates domains of function relevant to symptoms observed in autism.
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PMID:Impaired sociability and cognitive function in Nrcam-null mice. 1954 Feb 69

We report on a pedigree with a pair of brothers each with minor anomalies, developmental delay, and autistic-symptoms who share an unbalanced translocation (not detectable by karyotype). The unbalanced translocation involves a 7.1 Mb loss of the terminal portion of 10q, and a 4.2 Mb gain of 11q. One of the brothers also developed a cerebellar juvenile pilocytic astrocytoma. The father was found to be a balanced carrier and the couple had a previous miscarriage. We demonstrate that the breakpoint for the triplicated region from chromosome 11 is adjacent to two IgLON genes, namely Neurotrimin (NTM) and Opioid Binding Protein/Cell Adhesion Molecule-like (OPCML). These genes are highly similar neural cell adhesion molecules that have been implicated in synaptogenesis and oncogenesis, respectively. The children also have a 10q deletion and are compared to other children with the 10q deletion syndrome which generally does not involve autism spectrum disorders (ASDs) or cancer. Together these data support a role for NTM and OPCML in developmental delay and potentially in cancer susceptibility.
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PMID:An unbalanced translocation involving loss of 10q26.2 and gain of 11q25 in a pedigree with autism spectrum disorder and cerebellar juvenile pilocytic astrocytoma. 2349 67

Schizophrenia (SZ) and autism spectrum disorders (ASDs) are complex neurodevelopmental disorders that may share an underlying pathology suggested by shared genetic risk variants. We sequenced the exonic regions of 215 genes in 147 ASD cases, 273 SZ cases and 287 controls, to identify rare risk mutations. Genes were primarily selected for their function in the synapse and were categorized as: (1) Neurexin and Neuroligin Interacting Proteins, (2) Post-synaptic Glutamate Receptor Complexes, (3) Neural Cell Adhesion Molecules, (4) DISC1 and Interactors and (5) Functional and Positional Candidates. Thirty-one novel loss-of-function (LoF) variants that are predicted to severely disrupt protein-coding sequence were detected among 2 861 rare variants. We found an excess of LoF variants in the combined cases compared with controls (P=0.02). This effect was stronger when analysis was limited to singleton LoF variants (P=0.0007) and the excess was present in both SZ (P=0.002) and ASD (P=0.001). As an individual gene category, Neurexin and Neuroligin Interacting Proteins carried an excess of LoF variants in cases compared with controls (P=0.05). A de novo nonsense variant in GRIN2B was identified in an ASD case adding to the growing evidence that this is an important risk gene for the disorder. These data support synapse formation and maintenance as key molecular mechanisms for SZ and ASD.
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PMID:Excess of rare novel loss-of-function variants in synaptic genes in schizophrenia and autism spectrum disorders. 2412 26

Here we report three patients affected with neurodevelopmental disorders and harbouring 21q21 deletions involving NCAM2 gene. NCAM (Neural Cell Adhesion Molecule) proteins are involved in axonal migration, synaptic formation and plasticity. Poor axonal growth and fasciculation is observed in animal models deficient for NCAM2. Moreover, this gene has been proposed as a candidate for autism, based on genome-wide association studies. In this report, we provide a comprehensive molecular and phenotypical characterisation of three deletion cases giving additional clues for the involvement of NCAM2 in neurodevelopment.
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PMID:21q21 deletion involving NCAM2: report of 3 cases with neurodevelopmental disorders. 2546 10

Adhesion molecules of the immunoglobulin superfamily (IgSF) are essential for neuronal synapse development across evolution and control various aspects of synapse formation and maturation. Neph2, also known as Kirrel3, is an IgSF adhesion molecule implicated in synapse formation, synaptic transmission and ultrastructure. In humans, defects in the NEPH2 gene have been associated with neurodevelopmental disorders such as Jacobsen syndrome, intellectual disability, and autism-spectrum disorders. However, the precise role in development and function of the nervous system is still unclear. Here, we present the histomorphological and phenotypical analysis of a constitutive Neph2-knockout mouse line. Knockout mice display defects in auditory sensory processing, motor skills, and hyperactivity in the home-cage analysis. Olfactory, memory and metabolic testing did not differ from controls. Despite the wide-spread expression of Neph2 in various brain areas, no gross anatomic defects could be observed. Neph2 protein could be located at the cerebellar pinceaux. It interacted with the pinceau core component neurofascin and other synaptic proteins thus suggesting a possible role in cerebellar synapse formation and circuit assembly. Our results suggest that Neph2/Kirrel3 acts on the synaptic ultrastructural level and neuronal wiring rather than on ontogenetic events affecting macroscopic structure. Neph2-knockout mice may provide a valuable rodent model for research on autism spectrum diseases and neurodevelopmental disorders.
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PMID:Neph2/Kirrel3 regulates sensory input, motor coordination, and home-cage activity in rodents. 3013 26

Developmental synaptic remodeling is important for the formation of precise neural circuitry, and its disruption has been linked to neurodevelopmental disorders such as autism and schizophrenia. Microglia prune synapses, but integration of this synapse pruning with overlapping and concurrent neurodevelopmental processes, remains elusive. Adhesion G protein-coupled receptor ADGRG1/GPR56 controls multiple aspects of brain development in a cell type-specific manner: In neural progenitor cells, GPR56 regulates cortical lamination, whereas in oligodendrocyte progenitor cells, GPR56 controls developmental myelination and myelin repair. Here, we show that microglial GPR56 maintains appropriate synaptic numbers in several brain regions in a time- and circuit-dependent fashion. Phosphatidylserine (PS) on presynaptic elements binds GPR56 in a domain-specific manner, and microglia-specific deletion of Gpr56 leads to increased synapses as a result of reduced microglial engulfment of PS+ presynaptic inputs. Remarkably, a particular alternatively spliced isoform of GPR56 is selectively required for microglia-mediated synaptic pruning. Our present data provide a ligand- and isoform-specific mechanism underlying microglial GPR56-mediated synapse pruning in the context of complex neurodevelopmental processes.
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PMID:A splicing isoform of GPR56 mediates microglial synaptic refinement via phosphatidylserine binding. 3245 62