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)

Mutations in one of two genes, TSC1 and TSC2, result in a similar disease phenotype by disrupting the normal interaction of their protein products, hamartin and tuberin, which form a functional signaling complex. Disruption of these genes in the brain results in abnormal cellular differentiation, migration, and proliferation, giving rise to the characteristic brain lesions of tuberous sclerosis complex (TSC) called cortical tubers. The most devastating complications of TSC affect the central nervous system and include epilepsy, mental retardation, autism, and glial tumors. Relevant animal models, including conventional and conditional knockout mice, are valuable tools for studying the normal functions of tuberin and hamartin and the way in which disruption of their expression gives rise to the variety of clinical features that characterize TSC. In the future, these animals will be invaluable preclinical models for the development of highly specific and efficacious treatments for children affected with TSC.
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PMID:Tuberous sclerosis complex: molecular pathogenesis and animal models. 1688 89

We studied the magnetic resonance imaging (MRI) findings in a cohort of Chinese children with tuberous sclerosis complex to determine the relationship between age, sex, mental retardation, autism, epilepsy, infantile spasm, and early age at onset of seizures and the numbers and locations of tubers detected. We searched our tuberous sclerosis registry, established in 1985 (N = 44), and performed an analysis of children who had MRIs of the brain performed (n = 22). A neuroradiologist blinded to the clinical findings scored the MRIs according to the total number and site of the tubers. The following factors were analyzed: age, sex, presence of autism (n = 7), presence (n = 19) and severity of mental retardation (mild [n = 12], moderate to severe [n = 7]), presence of epilepsy (n = 21) or infantile spasm (n = 8), and age at onset of seizures less than 1 year (n = 10). There was no significant relationship between the number and site of tubers and the following factors: sex, autism, mental retardation, degree of mental retardation, epilepsy, history of infantile spasm, or age at onset of seizures less than 1 year. Only the presence of cortical tubers in the parietal regions had a significant relationship with the history of infantile spasm (P = .012). Using multiple regression analysis of all of the risk factors, only age is related to the number of tubers in the MRI (P = .047), and a history of infantile spasm is related to the presence of tubers in the parietal (P = .009) and occipital (P = .031) lobes. The associated comorbidities in tuberous sclerosis complex might be explained by more complex underlying genetic or pathologic issues rather than purely by the site of the cortical tubers. We suggest that a developmental approach, by analyzing the age at the appearance of tubers in both symptomatic and asymptomatic cases with the development of other neuropsychiatric comorbidities, should be undertaken to assess the causal relationship.
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PMID:Tuberous sclerosis complex: correlation of magnetic resonance imaging (MRI) findings with comorbidities. 1656 71

Tuberous sclerosis complex (TSC) is an autosomal dominant tumor syndrome that affects approximately 1 in 6000 individuals. It is characterized by the development of tumors, named hamartomas, in the kidneys, heart, skin and brain. The latter often cause seizures, mental retardation, and a variety of developmental disorders, including autism. This disease is caused by mutations within the tumor suppressor gene TSC1 on chromosome 9q34 encoding hamartin or within TSC2 on chromosome 16p13.3 encoding tuberin. TSC patients carry a mutant TSC1 or TSC2 gene in each of their somatic cells, and loss of heterozygosity has been documented in a wide variety of TSC tumors. Recent data suggest that functional inactivation of TSC proteins might also be involved in the development of other diseases not associated with TSC, such as sporadic bladder cancer, breast cancer, ovarian carcinoma, gall bladder carcinoma, non-small-cell carcinoma of the lung, and Alzheimer's disease. Tuberin and hamartin form a heterodimer, suggesting they might affect the same processes. Tuberin is assumed to be the functional component of the complex and has been implicated in the regulation of different cellular functions. The TSC proteins regulate cell size control due to their involvement in the insulin signalling pathway. Furthermore, they are potent positive regulators of the cyclin-dependent kinase inhibitor p27, a major regulator of the mammalian cell cycle. Here we review the current knowledge on how mutations within the TSC genes could trigger deregulation of stability and localization of the tumor suppressor p27.
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PMID:The tuberous sclerosis genes and regulation of the cyclin-dependent kinase inhibitor p27. 1671 32

We report here on a male diagnosed with tuberous sclerosis at 6 months of age. The child was treated with vigabatrin at age 6 months after an abnormal electroencephalogram but before onset of seizures. Vigabatrin was discontinued at age 13 months to avoid possible visual field defects. At 21 months, the child developed partial seizures with secondary generalization and infantile spasms. Standardized developmental assessments were performed at 12, 18, 24, 30, and 36 months of age. Cognitive and social development were normal until age 21 months and the onset of seizures. When assessed at 24 months, the child met criteria for autism and learning disability. This case indicates that the onset of epilepsy during an early stage in brain development can be associated with autistic regression and persistent developmental disorder. The case suggests the need to consider if possible visual field defects with vigabatrin outweigh the potentially deleterious effects of uncontrolled seizures.
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PMID:Autistic regression associated with seizure onset in an infant with tuberous sclerosis. 1742 12

Tuberous sclerosis (TS) is a relatively rare, autosomal dominant syndrome that displays high genetic penetrance in affected families. It is identified by a classic triad of symptoms including epilepsy, skin lesions, and mental retardation. Tuberous sclerosis causes hamartomas in multiple organ systems, including the brain, skin, heart, kidneys, lungs, and liver. Awareness of the signs and symptoms and the organs involved is critical to provide safe and effective anesthesia care. We describe a 10-year-old girl with TS scheduled to receive a general anesthetic for laser treatment of facial angiofibromas. The patient had several coexisting maladies from TS, including hypertension, autism, seizure disorder, cardiac rhabdomyomas, developmental delay, and bilateral polycystic renal disease. The laser procedure was performed, and there were no surgical or anesthetic complications. However, the potential for complications due to TS remained high throughout the provision of anesthesia care. Increased knowledge of TS and diligence in anesthesia practice can greatly reduce these risks.
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PMID:Anesthesia concerns for children with tuberous sclerosis. 1678 16

Tuberous sclerosis complex (TSC) is a multiorgan genetic disease caused by inactivation of either the TSC1 or TSC2 genes. The disorder typically has profound neurologic involvement and often presents early in life with epilepsy, developmental delay, mental retardation, and autism. These features are generally accepted to result from structural brain abnormalities that are found in patients with TSC. Although much progress has recently been made in discerning the function(s) of the TSC genes, many questions remain as to the role of these genes in brain development and homeostasis. This review will summarize recent progress and suggest future avenues of basic science research.
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PMID:The neurobiology of tuberous sclerosis complex. 1681 74

Few autistic brain samples are available for study, limiting investigations into molecular and histopathological abnormalities associated with this common disease. To facilitate distribution of samples, we have constructed a tissue array containing cerebral and cerebellar cores from 5 autistic children, 1 girl with Rett syndrome, and 5 age-matched controls. To demonstrate the utility of this resource, we examined phosphorylation of the S6 ribosomal protein, a signaling event regulated by the genes mutated in tuberous sclerosis and Cowden disease. We hypothesized that the molecular pathways altered in these inherited conditions associated with autism might be dysregulated in sporadic autistic cases as well. However, no consistent alterations in S6 phosphorylation were detected in autistic tissues compared to controls in the brain regions analyzed.
J Autism Dev Disord 2006 Nov
PMID:Brief report: S6 ribosomal protein phosphorylation in autistic frontal cortex and cerebellum: a tissue array analysis. 1684 79

We evaluated a 11-year-old male patient with mental delay, autism and brownish and whitish skin spots. The former resembled those of neurofibromatosis, the latter those of tuberous sclerosis. The patient received a complete clinical work-up to exclude neurofibromatosis, tuberous sclerosis, or any other known neurocutaneous disease, with biochemistry, chromosome analysis and analysis of skin specimens. Being all the other tests not significant, two main ultrastructural defects were observed. The first was a blockage in intracellular vescicular trafficking with sparing of the mitochondria; the second an aberrant presence of melanosomes in vacuoles of several cell lines and abnormal transfer of these organelles to keratinocytes. This patient presented with a unique clinical picture distinct from neurofibromatosis or tuberous sclerosis or any other known neurocutaneous disease. The ultrastructural abnormalities suggested a defect in cell trafficking involving several cell lines and compartments.
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PMID:Neurocutaneous syndrome with mental delay, autism, blockage in intracellular vescicular trafficking and melanosome defects. 1687 94

We assessed the structural and functional imaging features of cerebellar lesions and their neurobehavioral correlates in a large cohort of patients with tuberous sclerosis complex. A consecutive series of 78 patients with tuberous sclerosis complex underwent magnetic resonance imaging (MRI) and positron emission tomography (PET) studies with [(18)F]fluorodeoxyglucose (FDG) and alpha-[(11)C]methyl-l-tryptophan (AMT) as part of their evaluation for epilepsy surgery. Neurobehavioral assessment included the Gilliam Autism Rating Scales (GARS) and the Vineland Adaptive Behavior Scales (VABS). Twenty-one patients (27%) had cerebellar lesions (10 boys; mean age 9 +/- 8 years; 9 had right-sided, 10 had left-sided, and 2 had bilateral cerebellar lesions). The lesions showed decreased glucose metabolism (0.79 +/- 0.10) and increased (1.04 +/- 0.10) AMT uptake compared with the normal (nonlesional) cerebellar cortex. Comparisons between patients with (n = 20) and without (n = 57) a cerebellar lesion on neurobehavioral functioning, controlling for the number and location of cortical tubers, revealed that the cerebellar lesion group had higher overall autistic symptomatology. Within-group analyses of the cerebellar lesion group revealed that children with right-sided cerebellar lesions had higher social isolation and communicative and developmental disturbance compared with children with left-sided cerebellar lesions. The side of the cerebellar lesion was not related to adaptive behavior functioning. These findings provide additional empiric support for a role of the cerebellum in autistic symptomatology. Further investigation of the potential role of the right cerebellum in autism, particularly with regard to the dentatothalamofrontal circuit, is warranted.
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PMID:Cerebellar lesions in tuberous sclerosis complex: neurobehavioral and neuroimaging correlates. 1700 99

Tuberous sclerosis complex (TSC) is a multisystem disorder that affects numerous organ systems. Brain lesions that form during development, known as tubers, are highly associated with epilepsy, cognitive disability, and autism. Following the identification of two genes and their encoded proteins, TSC1 (hamartin) and TSC2 (tuberin), responsible for TSC, identification of several downstream protein cascades that might be affected in TSC have been discovered. Of primary importance is the mammalian target of rapamycin pathway that controls cell growth and protein synthesis. The mechanisms governing brain lesion growth have not been fully identified but likely altered regulation of the mammalian target of rapamycin cascade by hamartin and tuberin during development leads to aberrant cell growth. Secondary effects of TSC gene mutations might disrupt normal neuronal migration and cerebral cortical lamination. Numerous studies have identified changes in gene and protein expression in animal models of TSC and in human TSC brain specimens that contribute to altered brain cytoarchitecture. This review will provide an overview of the neurobiological aspects of TSC.
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PMID:The neurobiology of the tuberous sclerosis complex. 1702 74


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