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)

L-2-Hydroxyglutaric aciduria (L-2-HGA) is an autosomal recessive neurometabolic disorder characterized by psychomotor delay, ataxia, macrocephaly and typical neuroradiological findings of subcortical leucoencephalopathy. Recently, the disease causing gene has been discovered (L2HGDH) encoding L-2-hydroxyglutarate dehydrogenase. We present a 3-year-old boy with L-2-HGA, who demonstrated macrocephaly, noted already in utero with ultrasound. Cranial MRI demonstrated diffuse subcortical encephalopathy with increased signal of the subcortical white matter. Subsequent metabolic screening revealed increased levels of L-2-HGA, and genomic DNA analysis demonstrated two missense mutations in L-2-HGDG. Patient's further motor development was mildly impaired, whilst his speech development was profoundly impaired (first words at the age of 2 years). Since the age of 2 years he started demonstrating autistic repetitive behaviors and movements, increasing aloofness to his environment and limitations in the variety of spontaneous activity (CARS score: 44/60-severe autism). Autism has not so far been described in L-2-HGA and may be considered as an additional feature of the phenotypic spectrum.
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PMID:L-2-Hydroxyglutaric aciduria presenting with severe autistic features. 1798 16

The phosphatidylinositol 3-kinase (PI3K) signaling pathway modulates growth, proliferation and cell survival in diverse tissue types and plays specialized roles in the nervous system including influences on neuronal polarity, dendritic branching and synaptic plasticity. The tumor-suppressor phosphatase with tensin homology (PTEN) is the central negative regulator of the PI3K pathway. Germline PTEN mutations result in cancer predisposition, macrocephaly and benign hamartomas in many tissues, including Lhermitte-Duclos disease, a cerebellar growth disorder. Neurological abnormalities including autism, seizures and ataxia have been observed in association with inherited PTEN mutation with variable penetrance. It remains unclear how loss of PTEN activity contributes to neurological dysfunction. To explore the effects of Pten deficiency on neuronal structure and function, we analyzed several ultra-structural features of Pten-deficient neurons in Pten conditional knockout mice. Using Golgi stain to visualize full neuronal morphology, we observed that increased size of nuclei and somata in Pten-deficient neurons was accompanied by enlarged caliber of neuronal projections and increased dendritic spine density. Electron microscopic evaluation revealed enlarged abnormal synaptic structures in the cerebral cortex and cerebellum. Severe myelination defects included thickening and unraveling of the myelin sheath surrounding hypertrophic axons in the corpus callosum. Defects in myelination of axons of normal caliber were observed in the cerebellum, suggesting intrinsic abnormalities in Pten-deficient oligodendrocytes. We did not observe these abnormalities in wild-type or conditional Pten heterozygous mice. Moreover, conditional deletion of Pten drastically weakened synaptic transmission and synaptic plasticity at excitatory synapses between CA3 and CA1 pyramidal neurons in the hippocampus. These data suggest that Pten is involved in mechanisms that control development of neuronal and synaptic structures and subsequently synaptic function.
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PMID:Phosphatase and tensin homolog, deleted on chromosome 10 deficiency in brain causes defects in synaptic structure, transmission and plasticity, and myelination abnormalities. 1808 64

Fragile X syndrome, the most common inherited cause of intellectual impairment and the most common single gene associated with autism, generally occurs for fragile X mental retardation 1 (FMR1) alleles that exceed 200 CGG repeats (full-mutation range). Currently, there are no unbiased estimates of the number of full-mutation FMR1 alleles in the general population; a major obstacle is the lack of an effective screening tool for expanded FMR1 alleles in large populations. We have developed a rapid polymerase chain reaction (PCR)-based screening tool for expanded FMR1 alleles. The method utilizes a chimeric PCR primer that targets randomly within the expanded CGG region, such that the presence of a broad distribution of PCR products represents a positive result for an expanded allele. The method is applicable for screening both males and females and for allele sizes throughout the premutation (55 to 200 CGG repeats) and full-mutation ranges. Furthermore, the method is capable of rapid detection of expanded alleles using as little as 1% of the DNA from a single dried blood spot. The methodology presented in this work is suitable for screening large populations of newborn or those at high risk (eg, autism, premature ovarian failure, ataxia, dementia) for expanded FMR1 alleles. The test described herein costs less than $5 per sample for materials; with suitable scale-up and automation, the cost should approach $1 per sample.
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PMID:A rapid polymerase chain reaction-based screening method for identification of all expanded alleles of the fragile X (FMR1) gene in newborn and high-risk populations. 1816 73

Premutation carriers of repeat expansions in the fragile X mental retardation (FMR1) gene develop kinetic tremor and ataxia or the 'fragile X associated tremor/ataxia syndrome' (FXTAS). Affected FMR1 premutation carriers also have parkinsonism, but have not been reported to meet criteria for Parkinson disease. This case series illustrates that some patients who are FMR1 premutation carriers may appear by history and examination to have idiopathic Parkinson disease. Based on previous studies, it is likely that the genetic mutation and parkinsonism are associated. Although screening all PD patients is likely to be low yield, genetic testing of FMR1 in individuals with PD and a family history of fragile X syndrome, autism or developmental delay, or other related FMR1 phenotypes is warranted.
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PMID:Parkinsonism in FMR1 premutation carriers may be indistinguishable from Parkinson disease. 1856 83

Bipedal locomotion and fine motility of hand and larynx of humans introduced musculoskeletal adaptations, new pyramidal, corticostriatal, corticobulbar, nigrostriatal, and cerebellar pathways and expansions of prefrontal, cingular, parieto-temporal and occipital cortices with derived new brain capabilities. All selectively degenerate in aged homo sapiens following 16 syndromic presentations: (1) Parkinsonism: nigrostriatal control for fast automatic movements of hand, larynx, bipedal posture and gait ("simian gait and hand"). (2) Frontal (highest level) gait disorders (lower body parkinsonism, gait apraxia, retropulsion): prefrontostriatal executive control of bipedal locomotion. (3) ataxia: new synergistic coordination of bipedal gait and fine motility. (4) Dyskinesias (chorea, dystonia, tremor...): intrusions of simian basal ganglia motor subroutines. (5) motoneuron diseases: new proximo-distal and bulbar motoneurones, preserving older ones (oculomotor, abdominal...). (6) Archaic reflexes: prefrontal disinhibition of old mother/tree-climbing-oriented reflexes (sucking, grasping, Babinski/triple retraction, gegenhalten), group alarms (laughter, crying, yawning, grunting...) or grooming (tremor=scratching). (7) Dysautonomia: contextual regulation (orthostatism...). (8) REM sleep disorders of new cortical functions. (9) Corticobasal syndrome: melokinetic control of hand prehension-manipulation and language (retrocession to simian patterns). (10) Frontal/temporal lobe degeneration: medial-orbitofrontal behavioural variant: self monitoring of internal needs and social context: apathy, loss of personal hygiene, stereotypia, disinhibition, loss of concern for consequences of acts, social rules, danger and empathy; dorsolateral executive variant: inadequacy to the context of action (goal, environmental changes...); progressive non-fluent aphasia: executive and praxic processing of speech; temporal variant: abstract concepts for speech, gestures and vision (semantic dementia, progressive nonfluent aphasia) (11) Temporomesial-limbic-paralimbic-associative cortical dementias (Alzheimer's disease, Lewy body, progressive amnesia): processing of explicit cognition: amnesic syndrome, processing of hand, larynx and eye: disorientation, ideomotor apraxia, agnosia, visuospatial processing, transcortical aphasia. (12) Focal posterior atrophy (Benson, progressive apraxia): visuomotor processing of what and where. (13) Macular degeneration: retinal "spot" for explicit symbols. (14) "Psychiatric syndromes": metacognition, self monitoring and regulation of hierarchical processing of metacognition: hallucinations, delusions, magic and mystic logic, delusions, confabulations; drive: impulsivity, obsessive-compulsive disorders, mental automatisms; social interactions: theory of mind, autism, Asperger. (15) Mood disorders: control on emotions: anxio-depressive and bipolar disorders, moria, emotional lability. (16) Musculoskeletal: inclusion body myositis: muscles for bipedal gait and fine motility. Paget's disease: bones for bipedal gait and cranium. Understanding of the genetic mechanisms underlying the evolution of these recent human brain regions and paleoneurology my be the key to the focal, asymmetrical or systemic character of neurodegeneration, the pathologic heterogeneity/overlap of syndromic presentations associating gait, hand, language, cognition, mood and behaviour disorders.
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PMID:Paleoneurology: neurodegenerative diseases are age-related diseases of specific brain regions recently developed by Homo sapiens. 1870 90

Over the last decade, increasing evidence of cognitive functions of the cerebellum during development and learning processes could be ascertained. Posterior fossa malformations such as cerebellar hypoplasia or Joubert syndrome are known to be related to developmental problems in a marked to moderate extent. More detailed analyses reveal special deficits in attention, processing speed, visuospatial functions, and language. A study about Dandy Walker syndrome states a relationship of abnormalities in vermis lobulation with developmental problems. Further lobulation or volume abnormalities of the cerebellum and/or vermis can be detected in disorders as fragile X syndrome, Downs's syndrome, William's syndrome, and autism. Neuropsychological studies reveal a relation of dyslexia and attention deficit disorder with cerebellar functions. These functional studies are supported by structural abnormalities in neuroimaging in these disorders. Acquired cerebellar or vermis atrophy was found in groups of children with developmental problems such as prenatal alcohol exposure or extreme prematurity. Also, focal lesions during childhood or adolescence such as cerebellar tumor or stroke are related with neuropsychological abnormalities, which are most pronounced in visuospatial, language, and memory functions. In addition, cerebellar atrophy was shown to be a bad prognostic factor considering cognitive outcome in children after brain trauma and leukemia. In ataxia teleangiectasia, a neurodegenerative disorder affecting primarily the cerebellar cortex, a reduced verbal intelligence quotient and problems of judgment of duration are a hint of the importance of the cerebellum in cognition. In conclusion, the cerebellum seems to play an important role in many higher cognitive functions, especially in learning. There is a suggestion that the earlier the incorrect influence, the more pronounced the problems.
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PMID:Cerebellar disorders in childhood: cognitive problems. 1905 77

The FMR1 mutations can cause a variety of disabilities, including cognitive deficits, attention-deficit/hyperactivity disorder, autism, and other socioemotional problems, in individuals with the full mutation form (fragile X syndrome) and distinct difficulties, including primary ovarian insufficiency, neuropathy and the fragile X-associated tremor/ataxia syndrome, in some older premutation carriers. Therefore, multigenerational family involvement is commonly encountered when a proband is identified with a FMR1 mutation. Studies of metabotropic glutamate receptor 5 pathway antagonists in animal models of fragile X syndrome have demonstrated benefits in reducing seizures, improving behavior, and enhancing cognition. Trials of metabotropic glutamate receptor 5 antagonists are beginning with individuals with fragile X syndrome. Targeted treatments, medical and behavioral interventions, genetic counseling, and family supports are reviewed here.
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PMID:Advances in the treatment of fragile X syndrome. 1911 5

The calcium ion is one of the most versatile, ancient, and universal of biological signaling molecules, known to regulate physiological systems at every level from membrane potential and ion transporters to kinases and transcription factors. Disruptions of intracellular calcium homeostasis underlie a host of emerging diseases, the calciumopathies. Cytosolic calcium signals originate either as extracellular calcium enters through plasma membrane ion channels or from the release of an intracellular store in the endoplasmic reticulum (ER) via inositol triphosphate receptor and ryanodine receptor channels. Therefore, to a large extent, calciumopathies represent a subset of the channelopathies, but include regulatory pathways and the mitochondria, the major intracellular calcium repository that dynamically participates with the ER stores in calcium signaling, thereby integrating cellular energy metabolism into these pathways, a process of emerging importance in the analysis of the neurodegenerative and neuropsychiatric diseases. Many of the calciumopathies are common complex polygenic diseases, but leads to their understanding come most prominently from rare monogenic channelopathy paradigms. Monogenic forms of common neuronal disease phenotypes-such as seizures, ataxia, and migraine-produce a constitutionally hyperexcitable tissue that is susceptible to periodic decompensations. The gene families and genetic lesions underlying familial hemiplegic migraine, FHM1/CACNA1A, FHM2/ATP1A2, and FHM3/SCN1A, and monogenic mitochondrial migraine syndromes, provide a robust platform from which genes, such as CACNA1C, which encodes the calcium channel mutated in Timothy syndrome, can be evaluated for their role in autism and bipolar disease.
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PMID:Genetic calcium signaling abnormalities in the central nervous system: seizures, migraine, and autism. 1915 21

Mutations in the methyl-CpG-binding protein 2 (MeCP2) cause Rett syndrome, a severe neurodevelopmental disease associated with ataxia and other post-natal symptoms similar to autism. Much research interest has focussed on the implications of MeCP2 in disease and neuron physiology. However, little or no attention has been paid to how MeCP2 turnover is regulated. The post-translational control of MeCP2 is of critical importance, especially as subtle increases or decreases in MeCP2 amounts can affect neuron morphology and function. The latter point is of particular importance for gene therapeutic approaches in which exogenous wild-type MeCP2 is being introduced into diseased neurons. Further to this, we propose two hypotheses. The first hypothesis discusses the poly-ubiquitin-mediated post-translational regulation of MeCP2 through its two PEST domains. The second hypothesis explores the use of histone deacetylase inhibitors to modulate the amounts of MeCP2 expressed in conjunction with the aforementioned therapeutic approaches.
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PMID:MeCP2 post-translational regulation through PEST domains: two novel hypotheses: potential relevance and implications for Rett syndrome. 1931 13

CGG repeat expansions in the 5' noncoding region of the fragile X mental retardation 1 gene (FMR1) give rise to both neurodevelopmental and neurodegenerative human diseases depending on the length of the expansion. Expansions beyond 200 repeats (full mutation) generally result in gene silencing and fragile X syndrome (FXS), the leading heritable form of cognitive impairment and autism. Smaller expansions (55-200 CGG repeats; "premutation") give rise to the neurodegenerative disorder fragile X-associated tremor/ataxia syndrome (FXTAS) through an entirely distinct, toxic mRNA gain-of-function mechanism. A rapid means for both high-risk and newborn screening for allele size would provide a greater opportunity for early intervention and family counseling as well as furnish critical data on repeat size distribution and expanded allele frequencies. In the current work, we propose a novel mass spectrometry (MS) based method for the rapid identification of expanded CGG repeats to complement a recently described polymerase chain reaction (PCR) method for large population screening. In this combined approach, the optimized PCR method is used to amplify the relevant region of FMR1, followed by extensive nonspecific nuclease digestion. The resulting oligonucleotides are analyzed by MS in a manner that provides the relative proportion of triplet repeat oligonucleotides in seconds per sample. This assay enables swift and reproducible detection of expanded CGG alleles using a single blood spot and in principle is suitable for large scale studies and newborn screening. Moreover, this analytical scheme establishes a unique new intersection of MS with molecular biology, with potential for significant interdisciplinary impact.
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PMID:Polymerase chain reaction, nuclease digestion, and mass spectrometry based assay for the trinucleotide repeat status of the fragile X mental retardation 1 gene. 1951 25


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