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Patients with tuberous sclerosis complex (TSC) develop multi-organ disease manifestations, with kidney angiomyolipomas (AML) and cysts being one of the most common and deadly. Early and regular AML/cyst detection and monitoring are vital to lower TSC patient morbidity and mortality. However, the current standard of care involves imaging-based methods that are not designed for rapid screening, posing challenges for early detection. To identify potential diagnostic screening biomarkers of AML/cysts, we performed global untargeted metabolomics in blood samples from 283 kidney AML/cyst-positive or -negative TSC patients using mass spectrometry. We identified 7 highly sensitive chemical features, including octanoic acid, that predict kidney AML/cysts in TSC patients. Patients with elevated octanoic acid have lower levels of very long-chain fatty acids (VLCFAs), suggesting that dysregulated peroxisome activity leads to overproduction of octanoic acid via VLCFA oxidation. These data highlight AML/cysts blood biomarkers for TSC patients and offers valuable metabolic insights into the disease.

BACKGROUND: The TAND (Tuberous Sclerosis Complex [TSC]-Associated Neuropsychiatric Disorders) Checklist was developed as a clinical screener for neurodevelopmental disorders in TSC. Most studies have described patterns in older children and adults. This study sought to better understand behavioral concerns as measured by the TAND Checklist in young children with TSC. METHODS: We examined patterns of caregiver responses to the TAND Checklist in 90 toddlers with TSC (12 to 23 months n = 60; 24 to 36 months n = 30) through data collected during baseline visits across two TSC early intervention studies. RESULTS: Over 90% of caregivers reported at least one behavioral concern related to TAND. The number of concerns increased with age. Delayed language was the most frequently reported concern across ages (12 to 23 months: 58.3%, 24 to 36 months: 86.7%). Questions related to behavioral concerns were largely relevant in this age range, but questions in other areas, such as neuropsychological or academic function, were not. CONCLUSIONS: TAND symptoms are very common in toddlers with TSC, and these symptoms may increase with age. The TAND Checklist is a useful tool for identifying behavioral concerns efficiently, but several items and sections are not suited to younger children. Results support the development of an abbreviated form of the TAND Checklist for toddlers.

Subependymal giant cell astrocytoma (SEGA) is a rare, low‐grade glioma typically associated with tuberous sclerosis (TS) and mutations in the TSC1 or TSC2 genes. It is characterized by an intraventricular location, an expansive growth pattern, and the expression of glial and neural markers. TTF‐1 expression is considered a sensitive marker of SEGA, likely reflecting its origin from progenitor cells in the caudothalamic groove. We report a case of SEGA with unusual immunohistochemical and molecular features in a 20‐year‐old man with no signs or family history of TS. The tumor was located in the anterior horn of the right ventricle and obstructed the foramen of Monro. Histologically, it exhibited an expansive growth pattern and was composed of cells with ovoid nuclei and abundant eosinophilic cytoplasm. Immunohistochemically, the tumor cells were positive for GFAP and S‐100 protein, weakly positive for SOX2, focally positive for synaptophysin, and negative for TTF‐1, neurofilament protein, NeuN, EMA, chromogranin, and BCOR. Scattered OLIG2‐positive neoplastic cells were also observed. Molecular analysis revealed no pathogenic mutations or copy number variations in the analyzed 174 genes, including TSC1/2, except for a variant of unknown significance in BAP1. The histopathological features and immunohistochemical profile suggested SEGA, despite the absence of TTF‐1 expression and TSC1/2 mutations. The diagnosis was confirmed by DNA methylation profiling, which assigned the tumor to the methylation class “subependymal giant cell astrocytoma with TSC1/TSC2 alterations” with a calibrated score of 0.95. This case highlights the potential diagnostic pitfall of SEGA lacking TTF‐1 expression and emphasizes the importance of considering this entity in the differential diagnosis of intraventricular tumors, even in the absence of TS and characteristic molecular alterations. The existence of TTF‐1 negative SEGAs reveals that these tumors might also derive from TTF‐1 negative cells in the subpendymal region. [ABSTRACT FROM AUTHOR]

Background: Tuberous sclerosis complex (TSC) can present prenatally, often with cardiac rhabdomyomas, which, if large, may cause complications such as hydrops fetalis and reduced cardiac output. Prenatal treatment of these lesions with mTOR inhibitors, approved for other TSC manifestations, is under investigation. We hypothesize that mTOR inhibitors could help manage or prevent other TSC-related conditions, particularly neurological issues like epilepsy and CNS lesions, potentially improving neurodevelopmental outcomes. However, the safety of prenatal mTOR treatment remains a concern, especially for foetal development, and limited data are available on neurological outcomes. Methods: We conducted a literature review using PubMed, EMBASE, and Cochrane CENTRAL, focusing on studies involving mTOR inhibitors for prenatal TSC management. The search included case reports and series involving pregnant women diagnosed with TSC or early manifestations like cardiac rhabdomyomas. Keywords included "mTOR Inhibitor", "Rapamycin", "tuberous sclerosis complex", "prenatal", and "rhabdomyoma". Results: Three prenatal mouse studies and eight papers reporting on ten pregnant women treated with mTOR inhibitors were identified. Conclusions: The literature confirms that prenatal mTOR inhibitors may reduce cardiac rhabdomyomas. However, further studies are needed to explore their broader potential, particularly in preventing neurological complications, while carefully considering their impact on intrauterine growth and neurodevelopment. [ABSTRACT FROM AUTHOR]

Objective: To describe the clinical and ultrasonographic features of uterine perivascular epithelioid cell tumor (PEComa) using standardized terminology. Methods: This was a retrospective analysis of patients with uterine PEComa diagnosed and confirmed by pathology and immunohistochemistry at West China Second University Hospital, Sichuan University, Sichuan, China, between January 2010 and September 2023. The Morphological Uterus Sonographic Assessment (MUSA) consensus and the International Endometrial Tumor Analysis (IETA) consensus were utilized for the standardized description of the sonographic characteristics of uterine PEComa. We summarized the clinical and ultrasound features of uterine PEComa in cases from our center and those found in a review of the literature conducted using PubMed from 1 January 2013 to 30 September 2023 (inclusive). Results: Five patients, aged 33–57 (median, 52) years, with a total of six uterine PEComa lesions were included in our cohort. All cases had complete ultrasonographic and pathological images. None of the patients had a history of tuberous sclerosis complex. Two patients had malignant PEComa (one patient had two lesions) and three had benign PEComa, originating from the cervix, myometrium or uterine cavity. Patients presented with symptoms including increased vaginal discharge, vaginal bleeding and pelvic or abdominal pain. The three patients with benign PEComa underwent total hysterectomy and bilateral adnexectomy, tumor excision and conservative management, respectively, while both malignant cases underwent total hysterectomy and bilateral adnexectomy followed by chemotherapy. Regular follow‐up (from 6 to 24 months) revealed recurrence in one case. Two lesions were misdiagnosed as uterine fibroids, two as cervical cancer, one as metastatic cervical cancer (with myometrial invasion) and one was indeterminate. Ultrasound examination showed that most lesions displayed regular round or ovoid shape (66.7%), uniform echoes (66.7%) and hypoechogenicity (66.7%), with one (16.7%) malignant PEComa showing cystic areas and one (16.7%) benign PEComa showing punctate calcifications. All lesions lacked shadowing and the majority showed moderate to abundant vascularity (color score of 3–4, 83.3%). The color score was 2–4 in the periphery in 100% of cases and internally in 83.3% of cases. The three benign PEComas showed similar characteristics in vascular distribution, with scattered internal vessels and peripheral vessels exhibiting a circular pattern. The literature search identified 11 articles describing the ultrasonographic appearance of 18 cases of uterine PEComa, with similar characteristics to those in our cohort. Conclusions: The sonographic features of uterine PEComa include a uniform or non‐uniform hypoechogenic mass, typically round or ovoid with regular margins, occasionally containing cystic areas or calcifications, lacking shadowing and often showing moderate to abundant vascularity. Although the preoperative ultrasound diagnosis of uterine PEComa remains challenging, particularly given the non‐specific nature of the sonographic characteristics described here, dispersed intratumoral vessels and a peripheral circular vascular distribution may serve as diagnostic clues for uterine PEComa, but more cases are needed for confirmation. © 2024 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Context.--: Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors of uncertain histogenesis expressing smooth muscle and melanocytic markers. The clinicopathologic spectrum in young patients is not well documented. Objective.--: To describe a multi-institutional series of PEComas in children, adolescents, and young adults. Design.--: PEComas, not otherwise specified (NOS); angiomyolipomas (AMLs); lymphangioleiomyomatosis; and clear cell sugar tumors were retrospectively identified from 6 institutions and the authors' files. Results.--: Seventy PEComas in 64 patients (median age, 15 years) were identified. They were more common in females (45 of 64 patients), occurring predominantly in the kidney (53 of 70), followed by the liver (6 of 70). Thirty-four patients had confirmed tuberous sclerosis complex (TSC), 3 suspected TSC mosaicism, 2 Li-Fraumeni syndrome (LFS) and 1 neurofibromatosis type 1. Most common variants were classic (49 of 70) and epithelioid (8 of 70) AML. Among patients with AMLs, most (34 of 47) had TSC, and more TSC patients had multiple AMLs (15 of 36) than non-TSC patients (2 of 13). Two TSC patients developed malignant transformation of classic AMLs: 1 angiosarcomatous and 1 malignant epithelioid. Lymphangioleiomyomatosis (5 of 70) occurred in females only, usually in the TSC context (4 of 5). PEComas-NOS (6 of 70) occurred exclusively in non-TSC patients, 2 of whom had LFS (2 of 6). Three were malignant, 1 had uncertain malignant potential, and 2 were benign. All 4 PEComas-NOS in non-LFS patients had TFE3 rearrangements. Conclusions.--: Compared to the general population, TSC was more prevalent in our cohort; PEComas-NOS showed more frequent TFE3 rearrangements and possible association with LFS. This series expands the spectrum of PEComas in young patients and demonstrates molecular features and germline contexts that set them apart from older patients. [ABSTRACT FROM AUTHOR]

Aims: A subset of exceptionally rare primary renal perivascular epithelioid cell tumours (PEComas) that harbour Xp11.2 translocation have been reported, but no larger series devoted to this topic have been published. Methods and Results: We describe the clinicopathological and molecular features of 10 renal PEComas, collected from our routine and consultation files. There were five female and five male patients aged 14–65 (median: 32 years). One patient had a history of childhood neuroblastoma, but no patients were known to have a tuberous sclerosis complex or other hereditary disorder. Complete surgical excision was the treatment for all patients. The available follow‐up in five patients indicated a favourable outcome in 4/5 cases. Tumour size ranged from 2.8 to 15.2 cm (median, 5.2 cm). Immunohistochemistry revealed consistently strong TFE3 expression in all tumours, whereas PAX8 and keratin cocktails were uniformly negative. Other positive markers included HMB45 (7/9 tumours), CathepsinK (7/9 tumours), and CD117 (KIT) (3/5 tumours). TFE3 rearrangements were detected in 8/9 tumours (by targeted RNA sequencing in seven and by FISH in one). The identified fusion partners included SFPQ (n = 2) and one tumour each with ASPSCR1, ZC3H4, MED15, RBMX, and PRCC. One tumour that lacked TFE3 rearrangement by next‐generation sequencing (NGS) and fluorescence in situ hybridization (FISH) revealed a large intrachromosomal deletion involving PKD1 and TSC2 by DNA‐based NGS. Conclusion: This study highlights the morphologic and genetic diversity of TFE3‐rearranged primary renal PEComas and underlines the value of surrogate TFE3 immunohistochemistry in identifying them. The lack of PAX8 and keratin expression represents the mainstay for distinguishing these tumours from MiTF‐associated renal cell carcinomas. In addition, we report rare (ZC3H4, RBMX) and novel (MED15) TFE3 fusion partners in PEComa. [ABSTRACT FROM AUTHOR]

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Rheumatoid arthritis (RA) is a common autoimmune disease. Tuberous sclerosis complex(TSC) is a rare autosomal dominant disorder. We report a case of RA with TSC. The patient was a 46-year-old woman with polyarthritis and cough symptoms, rheumatoid arthritis associated interstitial lung disease (RA-ILD) was initially considered, and after more than 3 months of anti-rheumatic treatment, the patient still had cough, and further examination revealed that the patient had lymphangioleiomyomatosis in the lungs, hepatic and renal angiomyolipomas, multiple subependymal nodules, Vertebral osteosclerotic nodules, as well as facial angiofibromas and periungual fibroma, RA was finally diagnosed with TSC, and everolimus 10mg qd was added to anti-rheumatic therapy for 1 month, and the patient's cough symptoms were relieved. [ABSTRACT FROM AUTHOR]

Objective Methods Results Significance Epilepsy and intellectual disability are common in tuberous sclerosis complex (TSC). Although early life seizures and intellectual disability are known to be correlated in TSC, the differential effects of age at seizure onset and accumulated seizure burden on development remain unclear.Daily seizure diaries, serial neurodevelopmental testing, and brain magnetic resonance imaging were analyzed for 129 TSC patients followed from 0 to 36 months. We used machine learning to identify subgroups of patients based on neurodevelopmental test scores at 36 months of age and assessed the stability of those subgroups at 12 months. We tested the ability of candidate biomarkers to predict 36‐month neurodevelopmental subgroup using univariable and multivariable logistic regression. Candidate biomarkers included age at seizure onset, accumulated seizure burden, tuber volume, sex, and earlier neurodevelopmental test scores.Patients clustered into two neurodevelopmental subgroups at 36 months of age, higher and lower scoring. Subgroup was mostly (75%) the same at 12 months. Significant univariable effects on subgroup were seen only for accumulated seizure burden (largest effect), earlier test scores, and tuber volume. Neither age at seizure onset nor sex significantly distinguished 36‐month subgroups, although for girls but not boys there was a significant effect of age at seizure onset. In the multivariable model, accumulated seizure burden and earlier test scores together predicted 36‐month neurodevelopmental group with 82% accuracy and an area under the curve of .86.These results untangle the contributions of age at seizure onset and accumulated seizure burden to neurodevelopmental outcomes in young children with TSC. Accumulated seizure burden, rather than the age at seizure onset, most accurately predicts neurodevelopmental outcome at 36 months of age. These results emphasize the need to manage seizures aggressively during the first 3 years of life for patients with TSC, not only to promote seizure control but to optimize cognitive function. [ABSTRACT FROM AUTHOR]

DYRK1A, a ubiquitously expressed kinase, is linked to the dominant intellectual developmental disorder, microcephaly, and Down syndrome in humans. It regulates numerous cellular processes such as cell cycle, vesicle trafficking, and microtubule assembly. DYRK1A is a critical regulator of organ growth; however, how it regulates organ growth is not fully understood. Here, we show that the knockdown of DYRK1A in mammalian cells results in reduced cell size, which depends on mTORC1. Using proteomic approaches, we found that DYRK1A interacts with the tuberous sclerosis complex (TSC) proteins, namely TSC1 and TSC2, which negatively regulate mTORC1 activation. Furthermore, we show that DYRK1A phosphorylates TSC2 at T1462, a modification known to inhibit TSC activity and promote mTORC1 activity. We also found that the reduced cell growth upon knockdown of DYRK1A can be rescued by overexpression of RHEB, an activator of mTORC1. Our findings suggest that DYRK1A inhibits TSC complex activity through inhibitory phosphorylation on TSC2, thereby promoting mTORC1 activity. Furthermore, using the Drosophila neuromuscular junction as a model, we show that the mnb, the fly homologs of DYRK1A, is rescued by RHEB overexpression, suggesting a conserved role of DYRK1A in TORC1 regulation. [ABSTRACT FROM AUTHOR]

Background: Tuberous Sclerosis complex (TSC) is a multisystemic neurocutaneous genetic condition with high rates of morbidity and mortality from subependymal giant cell astrocytoma (SEGA), renal angiomyolipoma, and renal cyst complications. Everolimus is an inhibitor for mTORC1 and is currently used to treat TSC for its main role in rapidly reducing SEGA volume and seizure burden, although mainly studied in the adult population. It has also been shown to stabilize estimated glomerular filtration rate and reduce renal angiomyolipoma size in the adult population. Case presentation: This case report illustrates three pediatric patients placed on everolimus for SEGA and seizure control with incidental findings of the disappearance of or decreased burden of cystic kidney disease after everolimus therapy. In one patient, the cyst burden remained stable even after the cessation of everolimus while the SEGA resumed growth. Conclusions: This report demonstrates the utility of everolimus in not only renal angiomyolipomas but also cystic kidney disease particularly in pediatric patients with a promising role in preserving renal function and preventing long term sequelae such as hematuria and hemorrhage from larger renal cysts especially if used early on in disease course. [ABSTRACT FROM AUTHOR]

Benign tumors, but rarely cancer, are common in patients with tuberous sclerosis complex (TSC). Blood samples from patients undergoing treatment for TSC at our institution were analyzed for their individual sensitivity to ionizing radiation. Blood samples were collected from 13 adult patients with TSC. The samples were irradiated ex vivo and analyzed by 3-color fluorescence in situ hybridization. In each patient, aberrations were analyzed in 200 metaphases of chromosomes 1, 2, and 4 and scored as breaks. Radiosensitivity was determined by mean breaks per metaphase (B/M) and compared to both healthy donors and oncologic patients. The radiosensitivity (B/M) of the TSC patient cohort (n = 13; female: 46.2%, B/M: 0.48 ± 0.11) was clearly increased compared to healthy individuals of similar age (n = 90; female: 54.4%; B/M: 0.40 ± 0.09; p = 0.001). There was no difference compared to age-matched oncological patients (n = 78; female: 67.9%; B/M 0.49 ± 0.14; p = 0.246). Similarly, the proportion of radiosensitive (B/M > 0.5) and distinctly radiosensitive individuals (B/M > 0.6) was increased in the TSC and oncological patient cohorts (TSC: 30.8% and 7.7%, oncological patients: 46.2% and 14.1%) compared to the healthy individuals (11.1% and 2.2%). Although patients with TSC develop mostly benign and rarely malignant tumors, they are similarly sensitive to radiation as patients with malignant tumors. [ABSTRACT FROM AUTHOR]

Tuberous sclerosis complex (TSC) is a variable multisystem disorder. The "no mutations identified" (NMI) group are reportedly phenotypically milder than those with an identified molecular cause, and often have mosaic or intronic variants not detected by standard sequencing methods. Methods: We describe the phenotypes in an Australian TSC NMI group (n = 18) and a molecular testing strategy implementable in a diagnostic laboratory. Massively parallel sequencing (MPS) of the whole genomic regions of TSC1 and TSC2 was performed using DNA extracted from multiple tissue samples per participant. Results: Our study showed that the phenotype in TSC NMI individuals can be similar to those with heterozygous, particularly TSC1, variants. Although neurodevelopmental outcomes can be less severe, the number of organ systems involved was similar to the non‐mosaic groups. A diagnostic yield of 72% (13/18) was achieved, with the majority (10/13) being mosaic variants and the remainder heterozygous variants missed on previous testing. Conclusion: Testing DNA from multiple tissue samples allowed for validation of otherwise discarded low‐level mosaic variants and detection of mosaic variants by MPS without excessive cost or the need for specialised techniques. Implementing this approach in a diagnostic setting is viable and allows optimal clinical care of patients with NMI TSC. [ABSTRACT FROM AUTHOR]

For >30 years, the Eilat Conference on New Antiepileptic Drugs and Devices has provided a forum for the discussion of advances in the development of new therapies for seizures and epilepsy. The EILAT XVII conference took place in Madrid, Spain, on May 5–8, 2024. Participants included basic scientists and clinical investigators from industry and academia, other health care professionals, and representatives from lay organizations. We summarize in this article information on treatments in preclinical and in early clinical development discussed at the conference. These include AMT‐260, a gene therapy designed to downregulate the expression of Glu2K subunits of kainate receptors, in development for the treatment of drug‐resistant seizures associated with mesial temporal sclerosis; BHV‐7000, a selective activator of heteromeric Kv7.2/7.3 potassium channels, in development for the treatment of focal epilepsy; ETX101, a recombinant adeno‐associated virus serotype 9 designed to increase NaV1.1 channel density in inhibitory γ‐aminobutyric acidergic (GABAergic) neurons, in development for the treatment of SCN1A‐positive Dravet syndrome; GAO‐3‐02, a compound structurally related to synaptamide, which exerts antiseizure activity at least in part through an action on cannabinoid type 2 receptors; LRP‐661, a structural analogue of cannabidiol, in development for the treatment of seizures associated with Lennox–Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex; OV329, a selective inactivator of GABA aminotransferase, in development for the treatment of drug‐resistant seizures; PRAX‐628, a functionally selective potent sodium channel modulator with preference for the hyperexcitable state of sodium channels, in development for the treatment of focal seizures; RAP‐219, a selective negative allosteric modulator of transmembrane α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor regulatory protein γ‐8, in development for the treatment of focal seizures; and rozanolixizumab, a humanized anti‐neonatal Fc receptor monoclonal antibody, in development for the treatment of LGI1 autoimmune encephalitis. Treatments in more advanced development are summarized in Part II of this report. [ABSTRACT FROM AUTHOR]

Pediatric genetic epilepsies, such as CDKL5 Deficiency Disorder (CDD), are severely debilitating, with early-onset seizures occurring more than ten times daily in extreme cases. Existing antiseizure drugs frequently prove ineffective, which significantly impacts child development and diminishes the quality of life for patients and caregivers. The relaxation of cannabis legislation has increased research into potential therapeutic properties of phytocannabinoids such as cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC). CBD's antiseizure properties have shown promise, particularly in treating drug-resistant genetic epilepsies associated with Lennox–Gastaut syndrome (LGS), Dravet syndrome (DS), and Tuberous Sclerosis Complex (TSC). However, specific research on CDD remains limited. Much of the current evidence relies on anecdotal reports of artisanal products lacking accurate data on cannabinoid composition. Utilizing model systems like patient-derived iPSC neurons and brain organoids allows precise dosing and comprehensive exploration of cannabinoids' pharmacodynamics. This review explores the potential of CBD, THC, and other trace cannabinoids in treating CDD and focusing on clinical trials and preclinical models to elucidate the cannabinoid's potential mechanisms of action in disrupted CDD pathways and strengthen the case for further research into their potential as anti-epileptic drugs for CDD. This review offers an updated perspective on cannabinoid's therapeutic potential for CDD. [ABSTRACT FROM AUTHOR]

Simple Summary: Subependymal giant cell astrocytoma is a slow-growing brain tumor affecting children and young adults. Despite the characteristic molecular and clinical features, the severity of the disease varies from patient to patient, and, in addition, tumors in their early stages can be asymptomatic for a long time. Morbidity and mortality are due to the location of the tumor, which can obstruct the flow of cerebrospinal fluid, leading to progressive hydrocephalus and even death. The etiology and the response to treatment are still poorly understood due to the diversity of the background and the course of the disease. Therefore, this review aims to present and discuss the latest research on SEGA, its diagnosis, and treatment. Subependymal giant cell astrocytoma (SEGA) is most often found in patients with TSC (Tuberous Sclerosis Complex). Although it has been classified as a benign tumor, it may create a serious medical problem leading to grave consequences, including young patient demise. Surgery and chemotherapy belong to the gold standard of treatment. A broader pharmacological approach involves the ever-growing number of rapalogs and ATP-competitive inhibitors, as well as compounds targeting other kinases, such as dual PI3K/mTOR inhibitors and CK2 kinase inhibitors. Novel approaches may utilize noncoding RNA-based therapeutics and are extensively investigated to this end. The purpose of our review was to characterize SEGA and discuss the latest trends in the diagnosis and therapy of this disease. [ABSTRACT FROM AUTHOR]

Children with tuberous sclerosis complex (TSC) are at high risk for drug-resistant epilepsy (DRE). The ability to stratify those at highest risk for DRE is important for counseling and prompt, aggressive management, necessary to optimize neurocognitive outcomes. Using the extensively phenotyped PREVeNT cohort, we aimed to characterize whether the TSC genotype was associated with DRE. The study group (N = 70) comprised participants with TSC enrolled at age less than or equal to six months with detailed epilepsy and other phenotypic and genotypic data, prospectively collected as part of the PREVeNT trial. Genotype-phenotype correlations of DRE, time to first abnormal electroencephalography, and time to epilepsy onset were compared using Fisher exact test and regression models. Presence of a TSC2 pathogenic variant was significantly associated with DRE, compared with TSC1 and participants with no pathogenic mutation identified. In fact, all participants with DRE had a TSC2 pathogenic variant. Furthermore, TSC2 variants expected to result in no protein product were associated with higher risk for DRE. Finally, TSC1 pathogenic variants were associated with later-onset epilepsy, on average 21.2 months later than those with other genotypes. Using a comprehensively phenotyped cohort followed from infancy, this study is the first to delineate genotype-phenotype correlations for epilepsy severity and onset in children with TSC. Patients with TSC2 pathogenic variants, especially TSC2 pathogenic variants predicted to result in lack of TSC2 protein, are at highest risk for DRE, and are likely to have earlier epilepsy onset than those with TSC1. Clinically, these insights can inform counseling, surveillance, and management. [ABSTRACT FROM AUTHOR]

Background: Tuberous sclerosis (TSC)–associated kidney disease is a leading cause of mortality in adults with TSC. This study aimed to understand TSC features in children, particularly kidney involvement, to inform clinical care for this specific group. Methods: This retrospective cohort study included all paediatric (< 19 years) TSC cases at a large tertiary paediatric nephrology centre. Relevant data were collected from patients' records, statistical analyses were performed to identify associations between variables, survival probabilities were estimated with Kaplan‒Meier curves, and log-rank tests were conducted to assess survival differences among genetic mutations. Results: A total of 182 children with TSC were included. Among the 145 children with available kidney imaging data, 78.6% (114/145) exhibited kidney lesions. Angiomyolipomas (AMLs) were significantly more prevalent in the TSC2 mutation group (p = 0.018). Children with TSC2 mutations generally had poorer lesion-free survival than those with TSC1 mutations, but this difference was only significant for AMLs (p = 0.030). The change in size of largest AMLs increased with age and doubled in children above 9 years; a similar pattern was observed when stratified by genetic mutation. In contrast, kidney cysts exhibited two peaks: one in children under 5 years (2.31 mm/year) and the second in children between 15–19 years (2.82 mm/year). Chronic kidney disease was observed in 12.3% (10/81) of children, and high-risk AMLs above 3 cm were observed in 9% (13/145). Conclusions: While TSC kidney disease emerges later in the disease course than neurological features, our findings emphasise the importance of kidney surveillance during childhood, including routine kidney imaging, kidney function, and blood pressure monitoring. [ABSTRACT FROM AUTHOR]

Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder caused by mutations in the TSC1 or TSC2 gene. The aim of this study was to analyze the genotypes and phenotypes of Korean patients diagnosed with TSC and expand our understanding of this disorder. This retrospective observational study included 331 patients clinically diagnosed with TSC between November 1990 and April 2023 at Severance Children's Hospital, Seoul, South Korea. The demographic and clinical characteristics of the patients were investigated. Thirty novel variants were identified. Of the 331 patients, 188 underwent genetic testing, and genotype-phenotype variation was analyzed according to the type of gene mutation and functional domain. Fourty-nine patients (49/188, 26%) were had TSC1 mutations, 103 (55%) had TSC2 mutations, and 36 (19%) had no mutation identified (NMI). Hotspots were identified in exons 8 of TSC1 and exons 35 and 41 of TSC2. Patients with TSC2 mutations exhibited a significantly younger age at the time of seizure onset and had refractory epilepsy. Infantile epileptic spasms syndrome (IESS) was more common in the middle mutation domain of TSC2 than in the hamartin domain. Additionally, retinal hamartoma, cardiac rhabdomyoma, and renal abnormalities were significantly associated with TSC2 compared with other gene types. This study contributes to our understanding of TSC by expanding the genotypic spectrum with novel variants and providing insights into the clinical spectrum of patients with TSC in Korea. [ABSTRACT FROM AUTHOR]