Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0036572 (seizures)
80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tuberous Sclerosis Complex (TSC) is a multi-system disorder that is highly variable in its clinical presentation. Current molecular diagnostic methods permit identification of mutations in either TSC1 or TSC2 in 75-85% of TSC patients. Here we examine the clinical characteristics of those TSC patients who have no mutation identified (NMI). A retrospective review of our patient population that had comprehensive testing for mutations in TSC1/TSC2 identified 23/157 (15%) that were NMI. NMI patients had a lower incidence of brain findings on imaging studies, neurological features, and renal findings than those with TSC2 mutations. In contrast, NMI patients had a lower incidence of seizures than TSC patients with TSC1 mutations, but had a higher incidence of both renal angiomyolipomas and pulmonary lymphangioleiomyomatosis. This distinct constellation of findings suggest that NMI patients may have a unique molecular pathogenesis, different from that seen in TSC patients with the usual mutations in TSC1 and TSC2. We suggest that the mechanisms of disease in these patients include both mosaicism for a TSC2 mutation, and unusual non-coding region mutations in TSC2.
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PMID:Distinct clinical characteristics of tuberous sclerosis complex patients with no mutation identified. 1913 41

Tuberous sclerosis complex is an autosomal dominant disorder affecting primarily the central nervous system, skin, and kidney caused by mutations in the TSC1 and TSC2 genes. Diagnosis is established with the identification of various neurocutaneous symptoms and multiple organ system hamartomas. The authors report on a 9-year-old patient with episodes of vertigo and headache followed by full spontaneous recovery. There was no history of seizures, mental retardation, or other neurologic sequelae, and psychomotor development was normal. Magnetic resonance imaging revealed pial angiomatosis of the left cerebellum and calcifications in the left parieto-occipital lobe consistent with the diagnosis of Sturge-Weber syndrome. At the age of 13, multiple renal angiomyolipomas and a single hypomelanotic macule were found, and subsequent imaging revealed several cortical tuberi. The diagnosis was confirmed by sequence analysis, which identified a novel missense mutation p.Ala460Thr in exon 13 of the TSC2 gene. Thus, mild tuberous sclerosis due to a hypomorphic mutation in TSC2 may present with isolated leptomeningeal angiomatosis.
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PMID:Unusual radiological presentation of tuberous sclerosis complex with leptomeningeal angiomatosis associated with a hypomorphic mutation in the TSC2 gene. 1925 84

Cortical tubers are the hallmark of tuberous sclerosis. Their presence is expected on brain imaging, especially when seizures begin before 1 year of age with concomitant significant developmental delay. Increased tuber counts have been reported to be associated with seizures and poor cognitive outcome. We present a 3-year-old girl with intractable seizures that started as infantile spasms at 2 months of age and who was diagnosed with clinically definitive tuberous sclerosis. Poor prognostic signs included multiple seizure types, seizure onset before 1 year of age, and multifocal electroencephalographic abnormalities. However, on repeated brain magnetic resonance imaging scans, the known radiological findings associated with tuberous sclerosis complex were absent, raising a diagnostic dilemma. Therefore, genetic analysis was performed. A mutation was detected in the TSC2 gene, confirming the diagnosis. To the best of our knowledge, this is the first reported case of tuberless tuberous sclerosis complex associated with intractable epilepsy and developmental delay.
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PMID:Unusual clinical presentation of tuberless tuberous sclerosis complex. 1925 98

[Case records of Epileptic Disorders. Anatomo-electro clinical correlations. Case 01-2009]. Tuberous sclerosis complex (TSC) is a multisystem genetic disorder with variable phenotypic expression, caused by mutations in one of the two tumor suppressor genes, TSC1 or TSC2. Epilepsy is the most common neurological presentation and seizures are often medically intractable. Definition of the epileptogenic zone during presurgical evaluation is challenging given the multiple potentially epileptogenic lesions visible on MRI. However, TSC patients may nevertheless achieve seizure freedom, when preoperative evaluation yields concordant results. The strategies used in these patients vary substantially among different epilepsy surgery centres. We present a 21-year-old right-handed, intellectually not impaired woman with TSC and medically intractable seizures since the age of 15 years. Careful multi-stage presurgical evaluation, including prolonged video-EEG-monitoring, cerebral high resolution MRI, ictal and interictal [99m Tc]HMPAO-SPECT, [18 F]FDG-PET and further invasive recordings with subdural and depth electrodes led to the identification of an epileptogenic tuber with concordant seizure onset zone in the right neocortical temporal lobe. A tailored resection was performed leading to excellent surgical outcome (follow-up 12 months, Engel class I).
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PMID:Successful surgery in late onset epilepsy with tuberous sclerosis complex. 1934 55

Cortical tubers in patients with tuberous sclerosis complex are associated with disabling neurological manifestations, including intractable epilepsy. While these malformations are believed to result from the effects of TSC1 or TSC2 gene mutations, the molecular mechanisms leading to tuber formation, as well as the onset of seizures, remain largely unknown. We used the Affymetrix Gene Chip platform to provide the first genome-wide investigation of gene expression in surgically resected tubers, compared with histological normal perituberal tissue from the same patients or autopsy control tissue. We identified 2501 differentially expressed genes in cortical tubers compared with autopsy controls. Expression of genes associated with cell adhesion, for example, VCAM1, integrins and CD44, or with the inflammatory response, including complement factors, serpinA3, CCL2 and several cytokines, was increased in cortical tubers, whereas genes related to synaptic transmission, for example, the glial glutamate transporter GLT-1, and voltage-gated channel activity, exhibited lower expression. Gene expression in perituberal cortex was distinct from autopsy control cortex suggesting that even in the absence of tissue pathology the transcriptome is altered in TSC. Changes in gene expression yield insights into new candidate genes that may contribute to tuber formation or seizure onset, representing new targets for potential therapeutic development.
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PMID:Gene expression analysis of tuberous sclerosis complex cortical tubers reveals increased expression of adhesion and inflammatory factors. 1991 35

Of 105 children with epilepsy who had presurgical evaluation because of solitary extratemporal focal cortical dysplasia, the 5 cases reported here had a final diagnosis of tuberous sclerosis complex without classic findings on magnetic resonance imaging (MRI). Four were infants with spasms (n = 2) or partial seizures (n = 2); the fifth was a 12-year-old boy with right motor seizures. Cranial MRI indicated solitary left frontal dysplasia in two cases (one with calcification) and right frontal, left parietal, and right parietal dysplasia in one case each. Tuberous sclerosis complex was considered based on hypopigmented macules in three cases, on cardiac rhabdomyomas on echocardiography for hypotension in one case, and on calcification in the dysplastic region and a family history of seizures in one case. Four of the patients had mutations in the TSC1 (n = 2) and TSC2 (n = 2) genes. No mutation was found in the fifth patient, who had only TSC1 sequencing. Four had epilepsy surgery, and were seizure-free on one (three cases) or two antiepileptic drugs (one case) at 1-2 year follow-up. Pathologic examination revealed cortical dysplasia without any characteristic features of tuberous sclerosis complex. These findings suggest that, in tuberous sclerosis complex, solitary focal cortical dysplasia may be the only cranial MRI finding. Tuberous sclerosis complex should be considered when focal cortical dysplasia is associated with seizure onset in infancy, family history of seizures, and peridysplastic calcification.
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PMID:Tuberous sclerosis complex with a single brain lesion on MRI mimicking focal cortical dysplasia. 2039 89

Until recently, the neuropsychiatric phenotype of tuberous sclerosis complex (TSC) was presumed to be caused by the structural brain abnormalities and/or seizures seen in the disorder. However, advances in the molecular biology of the disorder have shown that TSC is a mammalian target of rapamycin (mTOR) overactivation syndrome, and that direct molecular pathways exist between gene mutation and cognitive/neurodevelopmental phenotype. Molecularly-targeted treatments using mTOR inhibitors (such as rapamycin) are showing great promise for the physical and neurological phenotype of TSC. Pre-clinical and early-phase clinical studies of the cognitive and neurodevelopmental features of TSC suggest that some of the neuropsychiatric phenotypes might also be reversible, even in adults with the disorder. TSC, fragile X, neurofibromatosis type 1, and disorders associated with phosphatase and tensin homo (PTEN) mutations, all signal through the mTOR signaling pathway, with the TSC1-TSC2 protein complex as a molecular switchboard at its center. Together, these disorders represent as much as 14% of autism spectrum disorders (ASD). Therefore, we suggest that this signaling pathway is a key to the underlying pathophysiology of a significant subset of individuals with ASD. The study of molecularly targeted treatments in TSC and related disorders, therefore, may be of scientific and clinical value not only to those with TSC, but to a larger population that may have a neuropsychiatric phenotype attributable to mTOR overactivation or dysregulation.
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PMID:Targeted treatments for cognitive and neurodevelopmental disorders in tuberous sclerosis complex. 2064 80

Tuberous sclerosis complex is a genetic multisystem disease characterized by hamartic development of many organs, most notably the brain, heart, kidneys, lungs, and skin. This autosomic dominant disorder results from mutations in one of two genes, TSC1 and TSC2, coding for hamartin and tuberin, respectively. The hamartin-tuberin complex inhibits the mammalian target of rapamycin pathway, which controls cell growth and proliferation. The clinical presentation is highly variable and most features of tuberous sclerosis become evident only in childhood after the child is several years of age, limiting their usefulness for early diagnosis. The aim of this article is to define the pediatric clinical manifestations of tuberous sclerosis in correlation with patient age. Sometimes, a prenatal diagnosis can be made based on fetal ultrasound and MRI, which show cardiac and brain lesions. However, newborns are most often asymptomatic. In the 1st year, seizures are the most common symptoms, with a high incidence of infantile spasms. In children between 2 and 10 years of age, neurological symptoms are the most frequent with epilepsy, mental retardation, and autism, but extraneurological manifestations can be diagnosed. In adolescents, most features of tuberous sclerosis become evident and renal and pulmonary manifestations must be sought. The knowledge of age-dependent clinical features of tuberous sclerosis can provide an earlier diagnosis and improve the management of these patients with a special role for multidisciplinary consultation.
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PMID:[Characteristics of tuberous sclerosis in children]. 2070 8

Tuberous Sclerosis Complex (TSC) is an autosomal dominant, multi-system disorder, typically involving severe neurological symptoms, such as epilepsy, cognitive deficits and autism. Two genes, TSC1 and TSC2, encoding the proteins hamartin and tuberin, respectively, have been identified as causing TSC. Although there is a substantial overlap in the clinical phenotype produced by TSC1 and TSC2 mutations, accumulating evidence indicates that TSC2 mutations cause more severe neurological manifestations than TSC1 mutations. In this study, the neurological phenotype of a novel mouse model involving conditional inactivation of the Tsc2 gene in glial-fibrillary acidic protein (GFAP)-positive cells (Tsc2(GFAP1)CKO mice) was characterized and compared with previously generated Tsc1(GFAP1)CKO mice. Similar to Tsc1(GFAP1)CKO mice, Tsc2(GFAP1)CKO mice exhibited epilepsy, premature death, progressive megencephaly, diffuse glial proliferation, dispersion of hippocampal pyramidal cells and decreased astrocyte glutamate transporter expression. However, Tsc2(GFAP1)CKO mice had an earlier onset and higher frequency of seizures, as well as significantly more severe histological abnormalities, compared with Tsc1(GFAP1)CKO mice. The differences between Tsc1(GFAP1)CKO and Tsc2(GFAP1)CKO mice were correlated with higher levels of mammalian target of rapamycin (mTOR) activation in Tsc2(GFAP1)CKO mice and were reversed by the mTOR inhibitor, rapamycin. These findings provide novel evidence in mouse models that Tsc2 mutations intrinsically cause a more severe neurological phenotype than Tsc1 mutations and suggest that the difference in phenotype may be related to the degree to which Tsc1 and Tsc2 inactivation causes abnormal mTOR activation.
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PMID:Tsc2 gene inactivation causes a more severe epilepsy phenotype than Tsc1 inactivation in a mouse model of tuberous sclerosis complex. 2106 1

Tuberous sclerosis complex (TSC) is a genetic condition characterized by the growth of benign tumours in multiple organs, including the brain and kidneys, alongside intellectual disability and seizures. Identification of a causative mutation in TSC1 or TSC2 is important for accurate genetic counselling in affected families, but it is not always clear from genetic data whether a sequence variant is pathogenic or not. In vitro functional analysis could provide support for determining whether an unclassified TSC1 or TSC2 variant is disease-causing. We have performed a detailed functional analysis of four patient-derived TSC2 mutations, E92V, R505Q, H597R and L1624P. One mutant, E92V, functioned similarly to wild-type TSC2, whereas H597R and L1624P had abnormal function in all assays, consistent with available clinical and segregation information. One TSC2 mutation, R505Q, was identified in a patient with intellectual disability, seizures and autistic spectrum disorder but who did not fulfil the diagnostic criteria for TSC. The R505Q mutation was also found in two relatives, one with mild learning difficulties and one without apparent phenotypic abnormality. R505Q TSC2 exhibited partially disrupted function in our assays. These data highlight the difficulties of assessing pathogenicity of a mutation and suggest that multiple lines of evidence, both genetic and functional, are required to assess the pathogenicity of some mutations.
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PMID:Determining the pathogenicity of patient-derived TSC2 mutations by functional characterization and clinical evidence. 2140 64


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