Tuberous Sclerosis Research Articles

Carbonic Anhydrase 2 Deletion Delays the Growth of Kidney Cysts Whereas Foxi1 Deletion Completely Abrogates Cystogenesis in TSC.

Tuberous sclerosis complex (TSC) presents with renal cysts and benign tumors, which eventually lead to kidney failure. The factors promoting kidney cyst formation in TSC are poorly understood. Inactivation of carbonic anhydrase 2 (Car2) significantly reduced, whereas, deletion of Foxi1 completely abrogated the cyst burden in Tsc1 KO mice. In these studies, we contrasted the ontogeny of cyst burden in Tsc1/Car2 dKO mice vs. Tsc1/Foxi1 dKO mice. Compared to Tsc1 KO, the Tsc1/Car2 dKO mice showed few small cysts at 47 days of age. However, by 110 days, the kidneys showed frequent and large cysts with overwhelming numbers of A-intercalated cells in their linings. The magnitude of cyst burden in Tsc1/Car2 dKO mice correlated with the expression levels of Foxi1 and was proportional to mTORC1 activation. This is in stark contrast to Tsc1/Foxi1 dKO mice, which showed a remarkable absence of kidney cysts at both 47 and 110 days of age. RNA-seq data pointed to profound upregulation of Foxi1 and kidney-collecting duct-specific H+-ATPase subunits in 110-day-old Tsc1/Car2 dKO mice. We conclude that Car2 inactivation temporarily decreases the kidney cyst burden in Tsc1 KO mice but the cysts increase with advancing age, along with enhanced Foxi1 expression.

Molecular Mechanisms and Roles of MiR-136-5p in Human Cancer and Other Disorders.

MiR-136-5p plays a vital function in regulating developmental processes as well as in the pathophysiology of diseases, with a notable record in tumor suppression. This article summarizes the latest findings on the physiological and pathophysiological processes of miR-136-5p in diseases. We searched for relevant studies and selected research articles from the last five years on PubMed with miR-136-5p as the keyword. MiR-136-5p represents a class of microRNAs (miRNAs) that are involved in various human maladies, encompassing cancers, cardio-cerebrovascular disease, diabetes, inflammatory disease, tuberous sclerosis, idiopathic pulmonary fibrosis, and polycystic ovary syndrome. Altered expression of miR-136-5p in specific ailments results in downstream gene expression imbalance, influencing cellular behaviors, such as migration, proliferation, and invasion. Furthermore, miR-136-5p is implicated in five signaling pathways, where it is critical in the onset and advancement of a number of illnesses. Additionally, it has the potential to promote drug resistance to a variety of medications. The current review aims to elucidate the role of miR-136-5p in both cancer progression and non-cancerous disorders, emphasizing dysregulated signaling pathways. It also sheds light on the potential of this miRNA as a prognostic biomarker in cancer, offering valuable insights and directions for future research.

The effectiveness of MRI in the management of pediatric epilepsy at a tertiary care hospital in Taif, Saudi Arabia

BackgroundEpilepsy is one of the most common disorders, affecting over 50 million individuals globally, with an incidence rate of 8.8 per 10,000 in Saudi Arabia. The study aimed to look into structural abnormalities in children with epilepsy using magnetic resonance imaging (MRI). Materials and methodsThis study used a cross-sectional design. Performed between July 2021 and March 2023, 107 patients (under the age of 12) who presented with epilepsy at Children's Hospital in Taif were randomly sampled. ResultsThe patients' mean age was 2 years and 4 months. Males (69.2%) were impacted more frequently than females (30.8%). The majority of the patients' MRI results (75.7%) were negative, whereas 24.3% had positive results with identifiable abnormalities. Approximately 65.4% exhibited aberrant electroencephalogram findings, while 34.6% had normal findings. The majority of seizures were generalized (65.4%), with focal seizures accounting for 9.3%. The most common cause of epilepsy revealed with MRI was white matter disease (6.5%), followed by mesial temporal sclerosis (2.8%), hippocampal pathology (1.9%), and hydrocephalus (1.9%). Tuberous sclerosis, grey matter heterotopia, Sturge-Weber Syndrome, and schizencephaly were the infrequent neuroimaging findings (0.9%) in this investigation. ConclusionMRI is critical for accurately identifying and controlling epilepsy in pediatric patients, since it provides precise classifications that assist in treatment planning and prognosis.

The tuberous sclerosis complex: a review of the literature

Tuberous sclerosis complex (TSC) is a neurocutaneous autosomal dominant genetic disorder characterized by mutations in the TSC1 and TSC2 genes, this leads to dysregulation of the mechanistic target of rapamycin (mTOR) pathway resulting in cellular hyperplasia and the formation of benign tumors in various organs, including the brain and skin. Clinical manifestations encompass a wide range of mainly neurological and dermatological symptoms, often presenting during early childhood and posing diagnostic challenges due to phenotypic variability. Recent advancements in diagnostic criteria, genetic testing, and imaging techniques have facilitated earlier diagnosis and increased disease incidence awareness. Neurologically, TSC commonly presents with cortical tubers, subependymal nodules (SENs), and epilepsy, with seizure control being paramount in preventing long-term neurodevelopmental sequelae. Dermatologically, hypomelanotic macules, facial angiofibromas, and ungual fibromas are hallmark features, often causing significant psychological distress due to disfigurement. Management of TSC requires a multidisciplinary approach, with emerging therapies such as mTOR inhibitors showing promise in addressing both neurological and dermatological manifestations. Early intervention, including epilepsy surgery and targeted treatments for skin lesions, is essential for optimizing outcomes and improving the quality of life for patients with TSC. Continued research into novel therapeutic modalities holds potential for further enhancing the management and prognosis of this complex disorder.

CBD in the Treatment of Epilepsy.

It has been several years since highly purified cannabidiol (CBD) was registered as a medication that can be used in children of at least 2 years of age to treat different types of seizures related to Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS), and more recently tuberous sclerosis complex (TSC). During this time, 39 randomized clinical trials (RCTs) and 13 meta-analyses on the efficacy and safety of CBD treatment have been published. Each of the meta-analyses had its own criteria for the RCTs' inclusion and, therefore, slightly different interpretations of the analyzed data. Each of them contributed in its own way to the understanding of CBD pharmacology, mechanisms of therapeutic action, development of adverse reactions, and drug-drug interactions. Hence, it seemed reasonable to gather the most relevant data in one article and present all the current knowledge on the use of CBD in epilepsy. The results of the 13 meta-analyses presented herein confirmed the effectiveness and safety of CBD in children and adolescents with DREs. In adults, reliable conclusions cannot be drawn due to insufficient data.

Lymphangioleiomyomatosis as a potent lung cancer risk factor: Insights from a Japanese large cohort study.

Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease associated with the functional tumour suppressor genes TSC1 and TSC2 and causes structural destruction in the lungs, which could potentially increase the risk of lung cancer. However, this relationship remains unclear because of the rarity of the disease. We investigated the relative risk of developing lung cancer among patients diagnosed with LAM between 2001 and 2022 at a single high-volume centre in Japan, using data from the Japanese Cancer Registry as the reference population. Next-generation sequencing (NGS) was performed in cases where tumour samples were available. Among 642 patients diagnosed with LAM (sporadic LAM, n = 557; tuberous sclerosis complex-LAM, n = 80; unclassified, n = 5), 13 (2.2%) were diagnosed with lung cancer during a median follow-up period of 5.13 years. All patients were female, 61.5% were never smokers, and the median age at lung cancer diagnosis was 53 years. Eight patients developed lung cancer after LAM diagnosis. The estimated incidence of lung cancer was 301.4 cases per 100,000 person-years, and the standardized incidence ratio was 13.6 (95% confidence interval, 6.2-21.0; p = 0.0008). Actionable genetic alterations were identified in 38.5% of the patients (EGFR: 3, ALK: 1 and ERBB2: 1). No findings suggested loss of TSC gene function in the two patients analysed by NGS. Our study revealed that patients diagnosed with LAM had a significantly increased risk of lung cancer. Further research is warranted to clarify the carcinogenesis of lung cancer in patients with LAM.

Preventative treatment of tuberous sclerosis complex with sirolimus: Phase I safety and efficacy results

AbstractObjectiveTuberous sclerosis complex (TSC) results from overactivity of the mechanistic target of rapamycin (mTOR). Sirolimus and everolimus are mTOR inhibitors that treat most facets of TSC but are understudied in infants. We sought to understand the safety and potential efficacy of preventative sirolimus in infants with TSC.MethodsWe conducted a phase 1 clinical trial of sirolimus, treating five patients until 12 months of age. Enrolled infants had to be younger than 6 months of age with no history of seizures and no clinical indication for sirolimus treatment. Adverse events (AEs), tolerability, and blood concentrations of sirolimus measured by tandem mass spectrometry were tracked through 12 months of age, and clinical outcomes (seizure characteristics and developmental profiles) were tracked through 24 months of age.ResultsThere were 92 AEs, with 34 possibly, probably, or definitely related to treatment. Of those, only two were grade 3 (both elevated lipids) and all AEs were resolved by the age of 24 months. During the trial, 94% of blood sirolimus trough levels were in the target range (5–15 ng/mL). Treatment was well tolerated, with less than 8% of doses held because of an AE (241 of 2941). Of the five patients, three developed seizures (but were well controlled on medications) at 24 months of age. Of the five patients, four had normal cognitive development for age. One was diagnosed with possible autism spectrum disorder.InterpretationThese results suggest that sirolimus is both safe and well tolerated by infants with TSC in the first year of life. Additionally, the preliminary work suggests a favorable efficacy profile compared with previous TSC cohorts not exposed to early sirolimus treatment. Results support sirolimus being studied as preventive treatment in TSC, which is now underway in a prospective phase 2 clinical trial (TSC‐STEPS).

Exploring an objective measure of overactivity in children with rare genetic syndromes

BackgroundOveractivity is prevalent in several rare genetic neurodevelopmental syndromes, including Smith-Magenis syndrome, Angelman syndrome, and tuberous sclerosis complex, although has been predominantly assessed using questionnaire techniques. Threats to the precision and validity of questionnaire data may undermine existing insights into this behaviour. Previous research indicates objective measures, namely actigraphy, can effectively differentiate non-overactive children from those with attention-deficit hyperactivity disorder. This study is the first to examine the sensitivity of actigraphy to overactivity across rare genetic syndromes associated with intellectual disability, through comparisons with typically-developing peers and questionnaire overactivity estimates.MethodsA secondary analysis of actigraphy data and overactivity estimates from The Activity Questionnaire (TAQ) was conducted for children aged 4-15 years with Smith-Magenis syndrome (N=20), Angelman syndrome (N=26), tuberous sclerosis complex (N=16), and typically-developing children (N=61). Actigraphy data were summarized using the M10 non-parametric circadian rhythm variable, and 24-hour activity profiles were modelled via functional linear modelling. Associations between actigraphy data and TAQ overactivity estimates were explored. Differences in actigraphy-defined activity were also examined between syndrome and typically-developing groups, and between children with high and low TAQ overactivity scores within syndromes.ResultsM10 and TAQ overactivity scores were strongly positively correlated for children with Angelman syndrome and Smith-Magenis syndrome. M10 did not substantially differ between the syndrome and typically-developing groups. Higher early morning activity and lower evening activity was observed across all syndrome groups relative to typically-developing peers. High and low TAQ group comparisons revealed syndrome-specific profiles of overactivity, persisting throughout the day in Angelman syndrome, occurring during the early morning and early afternoon in Smith-Magenis syndrome, and manifesting briefly in the evening in tuberous sclerosis complex.DiscussionThese findings provide some support for the sensitivity of actigraphy to overactivity in children with rare genetic syndromes, and offer syndrome-specific temporal descriptions of overactivity. The findings advance existing descriptions of overactivity, provided by questionnaire techniques, in children with rare genetic syndromes and have implications for the measurement of overactivity. Future studies should examine the impact of syndrome-related characteristics on actigraphy-defined activity and overactivity estimates from actigraphy and questionnaire techniques.

Validation of the Index for Facial Angiofibromas: Data analysis from a randomized controlled trial of sirolimus gel treatment in patients with tuberous sclerosis complex.

The Index for Facial Angiofibromas (IFA), a novel scoring system for angiofibromas, has been validated in patients with tuberous sclerosis complex (TSC). The objective of this analysis was to further validate the IFA using data from a clinical trial of topical sirolimus in patients with TSC. This was an analysis of photographs from a Phase III trial conducted in Japan (NCT02635789). Patients (n = 62) were randomized 1:1 to receive sirolimus or placebo gel for 12 weeks. Changes in angiofibromas were independently assessed using the primary composite endpoint, the Facial Angiofibroma Severity Index (FASI), and the IFA. Thresholds for a clinically meaningful change in IFA score were evaluated using receiver operating characteristic (ROC) analysis. The IFA scores had good-to-excellent inter-assessor reliability, very high intra-assessor reliability, and could be used to evaluate the distribution of disease severity at baseline. High correlations were observed between the categorized change from baseline in IFA scores and the primary composite endpoint (Kendall's coefficient of concordance, W = 0.8655, p < 0.0001), and between the change from baseline in IFA and FASI scores (Kendall's coefficient of concordance, W = 0.745, p < 0.0001). By ROC analysis, an optimal IFA cut-off point of 1.667 was determined to distinguish patients with markedly improved or improved angiofibromas from those with slightly improved or unchanged angiofibromas (area under the curve 0.937) as determined by the primary composite endpoint. The IFA score is potentially clinically useful because of its high validity and reliability. A decrease in score from baseline of ≥1.667 may be considered clinically meaningful.

Osteocytes/Osteoblasts Produce SAA3 to Regulate Hepatic Metabolism of Cholesterol.

Hypercholesterolaemia is a systemic metabolic disease, but the role of organs other than liver in cholesterol metabolism is unappreciated. The phenotypic characterization of the Tsc1Dmp1 mice reveal that genetic depletion of tuberous sclerosis complex 1 (TSC1) in osteocytes/osteoblasts (Dmp1-Cre) triggers progressive increase in serum cholesterol level. The resulting cholesterol metabolic dysregulation is shown to be associated with upregulation and elevation of serum amyloid A3 (SAA3), a lipid metabolism related factor, in the bone and serum respectively. SAA3, elicited from the bone, bound to toll-like receptor 4 (TLR4) on hepatocytes to phosphorylate c-Jun, and caused impeded conversion of cholesterol to bile acids via suppression on cholesterol 7 α-hydroxylase (Cyp7a1) expression. Ablation of Saa3 in Tsc1Dmp1 mice prevented the CYP7A1 reduction in liver and cholesterol elevation in serum. These results expand the understanding of bone function and hepatic regulation of cholesterol metabolism and uncover a potential therapeutic use of pharmacological modulation of SAA3 in hypercholesterolaemia.

Glycoprotein non-metastatic melanoma protein B promotes tumor growth and is a biomarker for lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a rare, progressive cystic lung disease affecting almost exclusively female-sexed individuals. The cysts represent regions of lung destruction caused by smooth muscle tumors containing mutations in one of the two tuberous sclerosis (TSC) genes. mTORC1 inhibition slows but does not stop LAM advancement. Furthermore, monitoring disease progression is hindered by insufficient biomarkers. Therefore, new treatment options and biomarkers are needed. LAM cells express melanocytic markers, including glycoprotein non-metastatic melanoma protein B (GPNMB). The function of GPNMB in LAM is currently unknown; however, GPNMB's unique cell surface expression on tumor versus benign cells makes GPNMB a potential therapeutic target, and persistent release of its extracellular ectodomain suggests potential as a serum biomarker. Here, we establish that GPNMB expression is dependent on mTORC1 signaling, and that GPNMB regulates TSC2-null tumor cell invasion in vitro. Further, we demonstrate that GPNMB enhances TSC2-null xenograft tumor growth in vivo, and that ectodomain release is required for this xenograft growth. We also show that GPNMB's ectodomain is released from the cell surface of TSC2-null cells by proteases ADAM10 and 17, and we identify the protease target sequence on GPNMB. Finally, we demonstrate that GPNMB's ectodomain is present at higher levels in LAM patient serum compared to healthy controls and that ectodomain levels decrease with mTORC1 inhibition, making it a potential LAM biomarker.

Long-term Effectiveness of Cannabidiol (CBD) Against Focal Seizures in Tuberous Sclerosis Complex (TSC): Results from the GWPCARE6 Open-label Extension (OLE) Trial (P8-1.001)

Long-term Effectiveness of Cannabidiol (CBD) Against Focal Seizures in Tuberous Sclerosis Complex (TSC): Results from the GWPCARE6 Open-label Extension (OLE) Trial (P8-1.001)

Morphological and Electrophysiological Characterization of Balloon and Giant Cells in Pediatric Cortical Dysplasia Type IIB and Tuberous Sclerosis Complex (P1-1.002)

Morphological and Electrophysiological Characterization of Balloon and Giant Cells in Pediatric Cortical Dysplasia Type IIB and Tuberous Sclerosis Complex (P1-1.002)

Functional Connectivity Between Tubers and the Somatomotor Areas and Cerebellum Is Associated with Impaired Social Affect in Tuberous Sclerosis Complex (S8.001)

Functional Connectivity Between Tubers and the Somatomotor Areas and Cerebellum Is Associated with Impaired Social Affect in Tuberous Sclerosis Complex (S8.001)

Caregiver-reported Nonseizure Outcomes with Real-world Use of Cannabidiol (CBD) in Tuberous Sclerosis Complex (TSC): Interim Results from the BECOME-TSC Survey (P8-1.010)

Caregiver-reported Nonseizure Outcomes with Real-world Use of Cannabidiol (CBD) in Tuberous Sclerosis Complex (TSC): Interim Results from the BECOME-TSC Survey (P8-1.010)

Caregiver-reported Seizure Outcomes with Real-world Use of Cannabidiol (CBD) in Tuberous Sclerosis Complex (TSC): Interim Results From the BECOME-TSC Survey (P8-1.005)

Caregiver-reported Seizure Outcomes with Real-world Use of Cannabidiol (CBD) in Tuberous Sclerosis Complex (TSC): Interim Results From the BECOME-TSC Survey (P8-1.005)

Clinicopathologic and Molecular Characterization of Xanthomatous Giant Cell Renal Cell Carcinomas: Further Support for a Close Morphologic Spectrum to Eosinophilic Solid and Cystic Renal Cell Carcinomas.

A recent study described a rare subtype of tuberous sclerosis complex ( TSC )-mutated renal cell carcinoma primarily characterized by Xanthomatous giant cell morphology. Only 2 cases in young individuals have been reported so far, making the correct diagnosis challenging from a pathological perspective. It remains unknown whether this tumor represents an independent subtype or belongs to other TSC -mutated tumors. We conducted a clinicopathologic evaluation and immunohistochemical profiling of 5 cases of Xanthomatous Giant Cell Renal Cell Carcinoma (XGC RCC) with confirmed TSC2 mutations through targeted DNA sequencing. In addition, we analyzed transcriptomic profiles using RNA-seq for the following samples: XGC RCC, Low-grade Oncocytic tumors (LOT), High-grade Oncocytic tumors/Eosinophilic Vacuolar Tumors (HOT/EVT), Eosinophilic Solid and Cystic Renal Cell Carcinomas (ESC RCC), Chromophobe cell Renal Cell Carcinomas (ChRCC), Renal Oncocytomas (RO), clear cell Renal Cell Carcinomas (ccRCC), and normal renal tissues. There were 2 female and 3 male patients, aged 22 to 58 years, who underwent radical nephrectomy for tumor removal. The tumor sizes ranged from 4.7 to 9.5cm in diameter. These tumors exhibited ill-defined boundaries, showed an expansive growth pattern, and featured distinctive tumor giant cells with abundant eosinophilic to Xanthomatous cytoplasm and prominent nucleoli. All tumors had low Ki-67 proliferation indices (<1%) and demonstrated immune reactivity for CD10, PAX8, CK20, CathepsinK, and GPNMB. Next-generation sequencing confirmed TSC2 mutations in all cases. RNA sequencing-based clustering indicated a close similarity between the tumor and ESC RCC. One patient (1/5) died of an accident 63 months later, while the remaining patients (4/5) were alive without tumor recurrences or metastases at the time of analysis, with a mean follow-up duration of 43.4 months. Our research supports the concept that Xanthomatous giant cell renal cell carcinoma (XGC RCC) shares clinicopathological and molecular characteristics with ESC RCC and shows a relatively positive prognosis, providing further support for a close morphologic spectrum between the two. We propose considering XGC RCC as a distinct subtype of ESC RCC.

Unusual presentation of cutaneous angiomyolipoma in the umbilical region: A case report

Background: Cutaneous angiomyolipoma (CAML) is a rare benign tumour originating from the perivascular cells of the smooth muscle and fat. Owing to its rarity, clinical presentation, size, and location, we report a case of interest. Case report: A 59-years-old male patient from the Etawah district presented with a lump in the anterior abdominal wall of the umbilical region for the past 5 months. The patient was asymptomatic, but was concerned about the nature of the lump and agreed to undergo excision of the lump, which revealed angiomyolipoma of the anterior abdominal wall on histopathological examination. The patient experienced no complications from the excision and was discharged from the hospital. This particular subsite is rare and lacks association with tuberous sclerosis, a clinical entity commonly associated with renal angiomyolipoma Conclusion: The final diagnosis was confirmed by histopathology based on the traditional criteria of the presence of blood vessels, fat tissue, and smooth muscles. Surgery is the preferred course of treatment, and complete resection is important because incomplete resection may cause recurrence. Keywords: benign; smooth muscle; tumor; blood vessel; adipose tissue

A Novel TSC2 c.2489T>C Missense Variant Associated With Tuberous Sclerosis Complex: Case Report.

Tuberous sclerosis complex (TSC) is a genetic disorder caused by a TSC1 or TSC2 gene variation characterized by widespread hamartomas in organs such as the skin, brain, heart, lungs, liver, and kidneys. We report a case of a patient with TSC who presented with broad clinical manifestations, including epilepsy. An 18-year-old man was diagnosed with recurrent drug-resistant epilepsy. Neuroimaging revealed bilateral cortical and subcortical tubers with multiple calcified subependymal nodules. His skin involvement and psychomotor retardation raised the suspicion of TSC. Genetic testing confirmed the diagnosis, and a combined treatment including mTOR inhibitors was initiated. TSC, although considered rare, needs to be considered when evaluating patients with broad clinical manifestations. Our report has significant implications for understanding the impact of genotype on the prognosis of TSC and the selection of treatment strategies for TSC-related refractory epilepsy.

183 Earlier Surgery is Associated With Improved Post-operative Language Development in Children With Tuberous Sclerosis Complex (TSC)

INTRODUCTION: Early life epilepsy in TSC has been strongly associated with lifelong intellectual disability. While improved seizure control correlates with improvements in quality of life and cognition, the importance of surgery timing in young children has not been well-studied. METHODS: Changes in patients’ preoperative (0-12 months) to postoperative (36 months) scores in neuropsychologic tests—including the Mullen Scales of Early Learning (MSEL), Vineland Adaptive Behavior Scales, Second Edition (VABS-II), and the Preschool Language Scales, 5th addition (PLS-5)—were calculated. Pearson correlation and multivariate linear regression models were used to correlate changes in test scores with age at surgery and separately with duration of epilepsy prior to surgery. Analysis was limited to those patients who demonstrated improved seizure control post-operatively (n = 18). RESULTS: Age at surgery had a statistically significant negative correlation with changes in the combined verbal sub-tests of the MSEL (R = -0.41, p = 0.04) and predicted the change in that measure outcome in a multivariate linear regression model (β: -0.09, p = 0.03). Similar trends were seen for the change in the total language score of the PLS-5 (R = -0.38, p = 0.06; β: -0.21, p = 0.07). Results were similar when the duration of epilepsy prior to surgery was assessed as the independent variable. However there were no clear trends with the VABS-II questionnaires, even in language domains. CONCLUSIONS: Our data shows that successful earlier surgery and shorter epilepsy duration prior to surgery are both associated with improved post-operative language development in a small cohort of patients with TSC. Prospective clinical trials are necessary to further elucidate this relationship.