BACKGROUND AND OBJECTIVES: Multiple factors have been found to contribute to the high risk of epilepsy in infants with tuberous sclerosis complex (TSC), including evolution of EEG abnormalities, TSC gene variant, and MRI characteristics. The aim of this prospective multicenter study was to identify early MRI biomarkers of epilepsy in infants with TSC aged <6 months and before seizure onset, and associate these MRI biomarkers with neurodevelopmental outcomes at 2 years of age. The study was part of the EPISTOP project. METHODS: We evaluated brain MRIs performed in infants younger than 6 months with TSC. We used harmonized MRI protocols across centers and children were monitored closely with neuropsychological evaluation and serial video EEG. MRI characteristics, defined as tubers, radial migration lines, white matter abnormalities, cysts, calcifications, subependymal nodules (SEN), and subependymal giant cell astrocytoma (SEGA), were visually evaluated and lesions were detected semiautomatically. Lesion to brain volume ratios were calculated and associated with epilepsy and neurodevelopmental outcomes at 2 years. RESULTS: Lesions were assessed on MRIs from 77 infants with TSC; 62 MRIs were sufficient for volume analysis. The presence of tubers and higher tuber-brain ratios were associated with the development of clinical seizures, independently of TSC gene variation and preventive treatment. Furthermore, higher tuber-brain ratios were associated with lower cognitive and motor development quotients at 2 years, independently of TSC gene variation and presence of epilepsy. DISCUSSION: In infants with TSC, there is a significant association between characteristic TSC lesions detected on early brain MRI and development of clinical seizures, as well as neurodevelopmental outcomes in the first 2 years of life. According to our results, early brain MRI findings may guide clinical care for young children with TSC. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that in infants with TSC, there is a significant association between characteristic TSC lesions on early brain MRI and the development of clinical seizures and neurodevelopmental outcomes in the first 2 years of life.
- MeSH
- dítě MeSH
- epilepsie * komplikace etiologie MeSH
- kojenec MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- předškolní dítě MeSH
- prospektivní studie MeSH
- tuberózní skleróza * komplikace diagnostické zobrazování genetika MeSH
- záchvaty komplikace MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- předškolní dítě MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- práce podpořená grantem MeSH
AIMS: Tuberous sclerosis complex (TSC) is a genetic disorder associated with dysregulation of the mechanistic target of rapamycin complex 1 (mTORC1) signalling pathway. Neurodevelopmental disorders, frequently present in TSC, are linked to cortical tubers in the brain. We previously reported microRNA-34a (miR-34a) among the most upregulated miRs in tubers. Here, we characterised miR-34a expression in tubers with the focus on the early brain development and assessed the regulation of mTORC1 pathway and corticogenesis by miR-34a. METHODS: We analysed the expression of miR-34a in resected cortical tubers (n = 37) compared with autopsy-derived control tissue (n = 27). The effect of miR-34a overexpression on corticogenesis was assessed in mice at E18. The regulation of the mTORC1 pathway and the expression of the bioinformatically predicted target genes were assessed in primary astrocyte cultures from three patients with TSC and in SH-SY5Y cells following miR-34a transfection. RESULTS: The peak of miR-34a overexpression in tubers was observed during infancy, concomitant with the presence of pathological markers, particularly in giant cells and dysmorphic neurons. miR-34a was also strongly expressed in foetal TSC cortex. Overexpression of miR-34a in mouse embryos decreased the percentage of cells migrated to the cortical plate. The transfection of miR-34a mimic in TSC astrocytes negatively regulated mTORC1 and decreased the expression of the target genes RAS related (RRAS) and NOTCH1. CONCLUSIONS: MicroRNA-34a is most highly overexpressed in tubers during foetal and early postnatal brain development. miR-34a can negatively regulate mTORC1; however, it may also contribute to abnormal corticogenesis in TSC.
- MeSH
- astrocyty metabolismus MeSH
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé MeSH
- mikro RNA genetika metabolismus MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mozek růst a vývoj patologie MeSH
- mozková kůra patologie MeSH
- myši inbrední C57BL MeSH
- neurony patologie MeSH
- předškolní dítě MeSH
- signální transdukce genetika MeSH
- tuberózní skleróza komplikace genetika patologie MeSH
- zvířata MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVE: To study the association between timing and characteristics of the first electroencephalography (EEG) with epileptiform discharges (ED-EEG) and epilepsy and neurodevelopment at 24 months in infants with tuberous sclerosis complex (TSC). METHODS: Patients enrolled in the prospective Epileptogenesis in a genetic model of epilepsy - Tuberous sclerosis complex (EPISTOP) trial, had serial EEG monitoring until the age of 24 months. The timing and characteristics of the first ED-EEG were studied in relation to clinical outcome. Epilepsy-related outcomes were analyzed separately in a conventionally followed group (initiation of vigabatrin after seizure onset) and a preventive group (initiation of vigabatrin before seizures, but after appearance of interictal epileptiform discharges [IEDs]). RESULTS: Eighty-three infants with TSC were enrolled at a median age of 28 days (interquartile range [IQR] 14-54). Seventy-nine of 83 patients (95%) developed epileptiform discharges at a median age of 77 days (IQR 23-111). Patients with a pathogenic TSC2 variant were significantly younger (P-value .009) at first ED-EEG and more frequently had multifocal IED (P-value .042) than patients with a pathogenic TSC1 variant. A younger age at first ED-EEG was significantly associated with lower cognitive (P-value .010), language (P-value .001), and motor (P-value .013) developmental quotients at 24 months. In the conventional group, 48 of 60 developed seizures. In this group, the presence of focal slowing on the first ED-EEG was predictive of earlier seizure onset (P-value .030). Earlier recording of epileptiform discharges (P-value .019), especially when multifocal (P-value .026) was associated with higher risk of drug-resistant epilepsy. In the preventive group, timing, distribution of IED, or focal slowing, was not associated with the epilepsy outcomes. However, when multifocal IEDs were present on the first ED-EEG, preventive treatment delayed the onset of seizures significantly (P-value <.001). SIGNIFICANCE: Early EEG findings help to identify TSC infants at risk of severe epilepsy and neurodevelopmental delay and those who may benefit from preventive treatment with vigabatrin.
- MeSH
- antikonvulziva terapeutické užití MeSH
- časná diagnóza * MeSH
- elektroencefalografie MeSH
- epilepsie diagnóza farmakoterapie etiologie MeSH
- hamartin genetika MeSH
- kojenec MeSH
- lidé MeSH
- novorozenec MeSH
- tuberin genetika MeSH
- tuberózní skleróza komplikace diagnóza genetika MeSH
- vigabatrin terapeutické užití MeSH
- vývojové poruchy u dětí epidemiologie etiologie MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky MeSH
- práce podpořená grantem MeSH
Tuberous sclerosis complex (TSC) is a dominant autosomal genetic disorder caused by loss-of-function mutations in TSC1 and TSC2, which lead to constitutive activation of the mammalian target of rapamycin C1 (mTORC1) with its decoupling from regulatory inputs. Because mTORC1 integrates an array of molecular signals controlling protein synthesis and energy metabolism, its unrestrained activation inflates cell growth and division, resulting in the development of benign tumors in the brain and other organs. In humans, brain malformations typically manifest through a range of neuropsychiatric symptoms, among which mental retardation, intellectual disabilities with signs of autism, and refractory seizures, which are the most prominent. TSC in the rat brain presents the first-rate approximation of cellular and molecular pathology of the human brain, showing many instructive characteristics. Nevertheless, the developmental profile and distribution of lesions in the rat brain, with neurophysiological and behavioral manifestation, deviate considerably from humans, raising numerous research and translational questions. In this study, we revisit brain TSC in human and Eker rats to relate their histopathological, electrophysiological, and neurobehavioral characteristics. We discuss shared and distinct aspects of the pathology and consider factors contributing to phenotypic discrepancies. Given the shared genetic cause and molecular pathology, phenotypic deviations suggest an incomplete understanding of the disease. Narrowing the knowledge gap in the future should not only improve the characterization of the TSC rat model but also explain considerable variability in the clinical manifestation of the disease in humans.
- MeSH
- druhová specificita MeSH
- duševní poruchy genetika patologie psychologie MeSH
- fenotyp * MeSH
- hamartin genetika MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- mozek patologie MeSH
- TOR serin-threoninkinasy genetika MeSH
- tuberin genetika MeSH
- tuberózní skleróza genetika patologie psychologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
PURPOSE: To perform comprehensive genotyping of TSC1 and TSC2 in a cohort of 94 infants with tuberous sclerosis complex (TSC) and correlate with clinical manifestations. METHODS: Infants were enrolled at age <4 months, and subject to intensive clinical monitoring including electroencephalography (EEG), brain magnetic resonance imaging (MRI), and neuropsychological assessment. Targeted massively parallel sequencing (MPS), genome sequencing, and multiplex ligation-dependent probe amplification (MLPA) were used for variant detection in TSC1/TSC2. RESULTS: Pathogenic variants in TSC1 or TSC2 were identified in 93 of 94 (99%) subjects, with 23 in TSC1 and 70 in TSC2. Nine (10%) subjects had mosaicism. Eight of 24 clinical features assessed at age 2 years were significantly less frequent in those with TSC1 versus TSC2 variants including cortical tubers, hypomelanotic macules, facial angiofibroma, renal cysts, drug-resistant epilepsy, developmental delay, subependymal giant cell astrocytoma, and median seizure-free survival. Additionally, quantitative brain MRI analysis showed a marked difference in tuber and subependymal nodule/giant cell astrocytoma volume for TSC1 versus TSC2. CONCLUSION: TSC2 pathogenic variants are associated with a more severe clinical phenotype than mosaic TSC2 or TSC1 variants in TSC infants. Early assessment of gene variant status and mosaicism might have benefit for clinical management in infants and young children with TSC.
- MeSH
- fenotyp MeSH
- hamartin genetika MeSH
- kojenec MeSH
- lidé MeSH
- mozaicismus MeSH
- mutace MeSH
- předškolní dítě MeSH
- tuberin genetika MeSH
- tuberózní skleróza * diagnostické zobrazování genetika MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- předškolní dítě MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited neurocutaneous disorder caused by inactivating mutations in TSC1 or TSC2, key regulators of the mechanistic target of rapamycin complex 1 (mTORC1) pathway. In the CNS, TSC is characterized by cortical tubers, subependymal nodules and subependymal giant cell astrocytomas (SEGAs). SEGAs may lead to impaired circulation of CSF resulting in hydrocephalus and raised intracranial pressure in patients with TSC. Currently, surgical resection and mTORC1 inhibitors are the recommended treatment options for patients with SEGA. In the present study, high-throughput RNA-sequencing (SEGAs n = 19, periventricular control n = 8) was used in combination with computational approaches to unravel the complexity of SEGA development. We identified 9400 mRNAs and 94 microRNAs differentially expressed in SEGAs compared to control tissue. The SEGA transcriptome profile was enriched for the mitogen-activated protein kinase (MAPK) pathway, a major regulator of cell proliferation and survival. Analysis at the protein level confirmed that extracellular signal-regulated kinase (ERK) is activated in SEGAs. Subsequently, the inhibition of ERK independently of mTORC1 blockade decreased efficiently the proliferation of primary patient-derived SEGA cultures. Furthermore, we found that LAMTOR1, LAMTOR2, LAMTOR3, LAMTOR4 and LAMTOR5 were overexpressed at both gene and protein levels in SEGA compared to control tissue. Taken together LAMTOR1-5 can form a complex, known as the 'Ragulator' complex, which is known to activate both mTORC1 and MAPK/ERK pathways. Overall, this study shows that the MAPK/ERK pathway could be used as a target for treatment independent of, or in combination with mTORC1 inhibitors for TSC patients. Moreover, our study provides initial evidence of a possible link between the constitutive activated mTORC1 pathway and a secondary driver pathway of tumour growth.
- MeSH
- adaptorové proteiny signální transdukční genetika metabolismus MeSH
- astrocytom etiologie genetika metabolismus MeSH
- astrocyty účinky léků metabolismus MeSH
- butadieny farmakologie MeSH
- dítě MeSH
- dospělí MeSH
- extracelulárním signálem regulované MAP kinasy antagonisté a inhibitory genetika metabolismus MeSH
- hamartin genetika MeSH
- inhibitory enzymů farmakologie MeSH
- intracelulární signální peptidy a proteiny genetika metabolismus MeSH
- kojenec MeSH
- lidé MeSH
- MAP kinasový signální systém genetika MeSH
- mechanistické cílové místo rapamycinového komplexu 1 MeSH
- messenger RNA metabolismus MeSH
- mikro RNA metabolismus MeSH
- mladiství MeSH
- mladý dospělý MeSH
- nádorové buňky kultivované MeSH
- nádory mozku komplikace genetika metabolismus MeSH
- nitrily farmakologie MeSH
- předškolní dítě MeSH
- sekvenční analýza RNA MeSH
- sekvenování transkriptomu MeSH
- stanovení celkové genové exprese MeSH
- tuberin genetika MeSH
- tuberózní skleróza komplikace genetika MeSH
- výměnné faktory guaninnukleotidů genetika metabolismus MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIM: We aimed to identify early predictors of intractable epilepsy, intellectual disability (ID) and autism spectrum disorders (ASD) in the cohort of TSC patients initially diagnosed with cardiac rhabdomyomas (CR). METHOD: Over the period of twelve years we prospectively obtained clinical, neuropsychological, electrophysiological and neuroimaging data in a group of 22 TSC patients (9 females, 13 males) with the pre/perinatal diagnosis of CR, included to the study at the time of diagnosis. Afterwards, we statistically determined variables associated with ID, ASD and intractable epilepsy. RESULTS: Development of ID was predicted by severe epilepsy (a higher number of anti-epileptic drugs used), a higher number of dysplastic lesions on MRI, and abnormal background activity on EEG (p < 0.05). Predictors of ASD included early developmental delay, abnormal background activity on EEG at the end of follow-up and a higher number of areas with dysplastic features on MRI (p < 0.05). Intractable epilepsy was associated with a higher number of areas with dysplastic features on MRI, ID and with TSC2 genotype. CONCLUSION: Adverse mental and clinical outcome was associated with intractable epilepsy and the severe anatomical brain involvement; therefore, our centre developed a tailored protocol for early identification of TSC patients at a higher risk of developing intractable epilepsy with its deleterious effect on cognitive outcome.
- MeSH
- genotyp MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mentální retardace etiologie MeSH
- poruchy autistického spektra etiologie MeSH
- předškolní dítě MeSH
- prospektivní studie MeSH
- refrakterní epilepsie etiologie MeSH
- tuberózní skleróza komplikace genetika psychologie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder causing benign tumors in the brain and other vital organs. The genes implicated in disease development are TSC1 and TSC2. Here, we have performed mutational analysis followed by a genotype-phenotype correlation study based on the clinical characteristics of the affected individuals. Twenty unrelated probands or families from Greece have been analyzed, of whom 13 had definite TSC, whereas another 7 had a possible TSC diagnosis. Using direct sequencing, we have identified pathogenic mutations in 13 patients/families (6 in TSC1 and 7 in TSC2), 5 of which were novel. The mutation identification rate for patients with definite TSC was 85%, but only 29% for the ones with a possible TSC diagnosis. Multiplex ligation-dependent probe amplification (MLPA) did not reveal any genomic rearrangements in TSC1 and TSC2 in the samples with no mutations identified. In general, TSC2 disease was more severe than TSC1, with more subependymal giant cell astrocytomas and angiomyolipomas, higher incidence of pharmacoresistant epileptic seizures, and more severe neuropsychiatric disorders. To our knowledge, this is the first comprehensive TSC1 and TSC2 mutational analysis carried out in TSC patients in Greece.
- MeSH
- delece genu MeSH
- dítě MeSH
- dospělí MeSH
- exony MeSH
- genetické asociační studie MeSH
- hamartin genetika MeSH
- lidé MeSH
- missense mutace MeSH
- mutační analýza DNA MeSH
- rodokmen MeSH
- terciární struktura proteinů MeSH
- tuberin genetika MeSH
- tuberózní skleróza genetika patologie MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Řecko MeSH
Tuberous Sclerosis Complex (TSC) is a rare genetic disorder that results from a mutation in the TSC1 or TSC2 genes leading to constitutive activation of the mechanistic target of rapamycin complex 1 (mTORC1). TSC is associated with autism, intellectual disability and severe epilepsy. Cortical tubers are believed to represent the neuropathological substrates of these disabling manifestations in TSC. In the presented study we used high-throughput RNA sequencing in combination with systems-based computational approaches to investigate the complexity of the TSC molecular network. Overall we detected 438 differentially expressed genes and 991 differentially expressed small non-coding RNAs in cortical tubers compared to autopsy control brain tissue. We observed increased expression of genes associated with inflammatory, innate and adaptive immune responses. In contrast, we observed a down-regulation of genes associated with neurogenesis and glutamate receptor signaling. MicroRNAs represented the largest class of over-expressed small non-coding RNA species in tubers. In particular, our analysis revealed that the miR-34 family (including miR-34a, miR-34b and miR-34c) was significantly over-expressed. Functional studies demonstrated the ability of miR-34b to modulate neurite outgrowth in mouse primary hippocampal neuronal cultures. This study provides new insights into the TSC transcriptomic network along with the identification of potential new treatment targets.
- MeSH
- dítě MeSH
- dospělí MeSH
- epilepsie genetika MeSH
- genetická transkripce genetika MeSH
- hamartin genetika MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mechanistické cílové místo rapamycinového komplexu 1 genetika MeSH
- mikro RNA genetika MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mozková kůra fyziologie MeSH
- mutace genetika MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- neurony fyziologie MeSH
- předškolní dítě MeSH
- signální transdukce genetika MeSH
- tuberin genetika MeSH
- tuberózní skleróza genetika MeSH
- zvířata MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- myši MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
