Burden of disease and unmet needs in tuberous sclerosis complex with neurological manifestations: systematic review

Aberrant TSC-Rheb axis in Oxytocin receptor+ cells mediate stress-induced anxiety

Stress is a major risk for the onset of several maladaptive processes including pathological anxiety, a diffuse state of heightened apprehension over anticipated threats1. Pathological anxiety is prevalent in up to 59% of patients with Tuberous Sclerosis complex (TSC)2, a neurodevelopmental disorder (NDD) caused by loss-of-function mutations in genes for Tuberin (Tsc2) and/or Hamartin (Tsc1) that together comprise the eponymous protein complex. Here, we generated cell type-specific heterozygous knockout of Tsc2 in cells expressing oxytocin receptor (OTRCs) to model pathological anxiety-like behaviors observed in TSC patient population. The stress of prolonged social isolation induces a sustained negative affective state that precipitates behavioral avoidance, often by aberrant oxytocin signaling in the limbic forebrain3,4. In response to social isolation, there were striking sex differences in stress susceptibility in conditional heterozygote mice when encountering situations of approach-avoidance conflict. Socially isolated male mutants exhibited behavioral avoidance in anxiogenic environments and sought more social interaction for buffering of stress. In contrast, female mutants developed resilience during social isolation and approached anxiogenic environments, while devaluing social interaction. Systemic and medial prefrontal cortex (mPFC)-specific inhibition of downstream effector of TSC, the integrated stress response (ISR), rescued behavioral approach toward anxiogenic environments and conspecifics in male and female mutant mice respectively. Further, we found that Tsc2 deletion in OTRCs leads to OTR-signaling elicited network suppression, i.e., hypofrontality, in male mPFC, which is relieved by inhibiting the ISR. Our findings present evidence in support of a sexually dimorphic role of prefrontal OTRCs in regulating emotional responses in anxiogenic environments, which goes awry in TSC. Our work has broader implications for developing effective treatments for subtypes of anxiety disorders that are characterized by cell-autonomous ISR and prefrontal network suppression.

Single variant, yet "double trouble": TSC and KBG syndrome because of a large de novo inversion

Despite the advances in high-throughput sequencing, many rare disease patients remain undiagnosed. In particular, the patients with well-defined clinical phenotypes and established clinical diagnosis, yet missing or partial genetic diagnosis, may hold a clue to more complex genetic mechanisms of a disease that could be missed by available clinical tests. Here, we report a patient with a clinical diagnosis of Tuberous sclerosis, combined with unusual secondary features, but negative clinical tests including TSC1 and TSC2 Short-read whole-genome sequencing combined with advanced bioinformatics analyses were successful in uncovering a de novo pericentric 87-Mb inversion with breakpoints in TSC2 and ANKRD11, which explains the TSC clinical diagnosis, and confirms a second underlying monogenic disorder, KBG syndrome. Our findings illustrate how complex variants, such as large inversions, may be missed by clinical tests and further highlight the importance of well-defined clinical diagnoses in uncovering complex molecular mechanisms of a disease, such as complex variants and "double trouble" effects.

The association between computed tomography attenuation value of renal angiomyolipoma associated with tuberous sclerosis complex and response to everolimus

BACKGROUND

The response to everolimus in patients with renal angiomyolipoma associated with tuberous sclerosis complex (TSC-RAML) varies among individuals. This study aims to identify potential factors associated with the response to everolimus.

METHOD

We retrospectively examined data encompassing age, gender, tumor size, computed tomography attenuation value (CT value), CT enhancement, and tumor reduction rate in patients with TSC-RAML undergoing everolimus in two previously registered clinical trials.

RESULT

A total of 33 participants (29.33 ± 6.63 years old, 20 females) were included. The correlation analysis conducted separately for tumors located in the left and right kidneys revealed significant negative correlations (P < 0.05) between tumor reduction rate and age, as well as tumor size. While significant positive correlations (P < 0.05) were observed between tumor reduction rate and unenhanced CT value as well as CT enhancement. Nonetheless, based on multiple linear regression analysis, unenhanced CT value emerged as the sole-independent predictor of tumor reduction rate among age, gender, tumor size, unenhanced CT value and CT enhancement for both left (coefficient = 0.00319, P < 0.0001) and right kidneys (coefficient = 0.00315, P = 0.0104). Notable reductions were observed in unenhanced CT value (- 3.81 vs - 24.70HU, P < 0.0001) and CT enhancement (48.16 vs 33.56HU, P < 0.0001) following a 3-month administration of everolimus. The decline in both unenhanced CT value and tumor size predominantly occurred within the initial 3 months, subsequently maintaining a relatively stable level throughout the treatment.

CONCLUSION

The unenhanced CT value of TSC-RAML showed an independent correlation with the response to everolimus, suggesting its potential as a predictor of everolimus efficacy in patients with TSC-RAML.

[Genetic diffuse cystic lung disease in adults]

Multiple cystic lung diseases comprise a wide range of various diseases, some of them of genetic origin. Lymphangioleiomyomatosis (LAM) is a disease occurring almost exclusively in women, sporadically or in association with tuberous sclerosis complex (TSC). Patients with LAM present with lymphatic complications, renal angiomyolipomas and cystic lung disease responsible for spontaneous pneumothoraces and progressive respiratory insufficiency. TSC and LAM have been ascribed to mutations in TSC1 or TSC2 genes. Patients with TSC are variably affected by cutaneous, cognitive and neuropsychiatric manifestations, epilepsy, cerebral and renal tumors, usually of benign nature. Birt-Hogg-Dubé syndrome is caused by mutations in FLCN encoding folliculin. This syndrome includes lung cysts of basal predominance, cutaneous fibrofolliculomas and various renal tumors. The main complications are spontaneous pneumothoraces and renal tumors requiring systematic screening. The mammalian target of rapamycin (mTOR) pathway is involved in the pathophysiology of TSC, sporadic LAM and Birt-Hogg-Dubé syndrome. MTOR inhibitors are used in LAM and in TSC while Birt-Hogg-Dubé syndrome does not progress towards chronic respiratory failure. Future challenges in these often under-recognized diseases include the need to reduce the delay to diagnosis, and to develop potentially curative treatments. In France, physicians can seek help from the network of reference centers for the diagnosis and management of rare pulmonary diseases.

International consensus recommendations for the identification and treatment of tuberous sclerosis complex-associated neuropsychiatric disorders (TAND)

BACKGROUND

Tuberous sclerosis complex (TSC) is associated with a wide range of physical manifestations for which international clinical recommendations for diagnosis and management have been established. TSC is, however, also associated with a wide range of TSC-Associated Neuropsychiatric Disorders (TAND) that are typically under-identified and under-treated yet associated with a profound burden of disease. The contemporary evidence base for the identification and treatment of TAND is much more limited and, to date, consensus recommendations for the diagnosis and management of TAND have also been limited and non-specific.

METHODS

The TANDem project was launched with an international, interdisciplinary, and participatory consortium of 24 individuals, including TSC family representatives, from all World Health Organization (WHO) regions but one. One of the aims of the TANDem project was to generate consensus recommendations for the identification and treatment of TAND. At the time of this project, no internationally adopted standard methodology and methodological checklists existed for the generation of clinical practice recommendations. We therefore developed our own systematic procedure for evidence review and consensus-building to generate evidence-informed consensus recommendations of relevance to the global TSC community.

RESULTS

At the heart of the consensus recommendations are ten core principles surrounded by cluster-specific recommendations for each of the seven natural TAND clusters identified in the literature (autism-like, dysregulated behavior, eat/sleep, mood/anxiety, neuropsychological, overactive/impulsive, and scholastic) and a set of wraparound psychosocial cluster recommendations. The overarching recommendation is to "screen" for TAND at least annually, to "act" using appropriate next steps for evaluation and treatment, and to "repeat" the process to ensure early identification and early intervention with the most appropriate biological, psychological, and social evidence-informed approaches to support individuals with TSC and their families.

CONCLUSIONS

The consensus recommendations should provide a systematic framework to approach the identification and treatment of TAND for health, educational, social care teams and families who live with TSC. To ensure global dissemination and implementation of these recommendations, partnerships with the international TSC community will be important. One of these steps will include the generation of a "TAND toolkit" of "what to seek" and "what to do" when difficulties are identified in TAND clusters.

Understanding speech and language in tuberous sclerosis complex

Tuberous Sclerosis Complex (TSC), is a neurocutaneous disorder, associated with a high prevalence of autism spectrum disorder (ASD; ∼50% of individuals). As TSC is a leading cause of syndromic ASD, understanding language development in this population would not only be important for individuals with TSC but may also have implications for those with other causes of syndromic and idiopathic ASD. In this mini review, we consider what is known about language development in this population and how speech and language in TSC are related to ASD. Although up to 70% of individuals with TSC report language difficulties, much of the limited research to date on language in TSC has been based on summary scores from standardized assessments. Missing is a detailed understanding of the mechanisms driving speech and language in TSC and how they relate to ASD. Here, we review recent work suggesting that canonical babbling and volubility-two precursors of language development that predict the emergence of speech and are delayed in infants with idiopathic ASD-are also delayed in infants with TSC. We then look to the broader literature on language development to identify other early precursors of language development that tend to be delayed in children with autism as a guide for future research on speech and language in TSC. We argue that vocal turn-taking, shared attention, and fast mapping are three such skills that can provide important information about how speech and language develop in TSC and where potential delays come from. The overall goal of this line of research is to not only illuminate the trajectory of language in TSC with and without ASD, but to ultimately find strategies for earlier recognition and treatment of the pervasive language difficulties in this population.

Morphological Features of Language Regions in Individuals with Tuberous Sclerosis Complex

A significant number of individuals with tuberous sclerosis complex (TSC) exhibit language difficulties. Here, we examined the language-related brain morphometry in 59 participants (7 participants with TSC and comorbid autism spectrum disorder (ASD) (TSC + ASD), 13 with TSC but no ASD (TSC-ASD), 10 with ASD-only (ASD), and 29 typically developing (TD) controls). A hemispheric asymmetry was noted in surface area and gray matter volume of several cortical language areas in TD, ASD, and TSC-ASD groups, but not in TSC + ASD group. TSC + ASD group demonstrated increased cortical thickness and curvature values in multiple language regions for both hemispheres, compared to other groups. After controlling for tuber load in the TSC groups, within-group differences stayed the same but the differences between TSC-ASD and TSC + ASD were no longer statistically significant. These preliminary findings suggest that comorbid ASD in TSC as well as tuber load in TSC is associated with changes in the morphometry of language regions. Future studies with larger sample sizes will be needed to confirm these findings.

The Burden of Caring for Individuals with Tuberous Sclerosis Complex (TSC) Who Experience Epileptic Seizures: A Descriptive UK Survey

INTRODUCTION

Tuberous sclerosis complex (TSC) is a rare multisystem genetic condition characterised by benign tumours; prevalent manifestations include epilepsy and neuropsychiatric disorders. This study examined the burden of TSC for primary caregivers and families, exploring the impact of characteristics such as seizures.

METHODS

Primary caregivers of individuals with TSC in the United Kingdom participated in an online survey, comprising the Pediatric Quality of Life Inventory™ Family Impact Module, Hospital Anxiety and Depression Scale (HADS), and TSC-specific items. Responses were analysed using descriptive and regression analysis statistics (closed-ended) or qualitative content analysis (open-ended).

RESULTS

Seventy-three participants partially completed and 59 fully completed the survey; 95% were female, and 90% were parents of an individual with TSC. A median (range) of 2 (1-11) household members were carers. Primary caregivers spent a mean (standard deviation [SD]) of 104.3 (51.7) hours caring in the previous week, reporting high mean (SD) HADS scores of 11.2 (4.8) (anxiety) and 7.9 (4.4) (depression) and considerable family burden. Increased seizure frequency increased hours spent caring by primary caregivers (p = 0.01) and was associated with a decreased mean (SD) family functioning score of 46.2 (23.0) and parent health-related quality of life (HRQL) score of 45.4 (20.3) (both p = 0.03). Multivariable models predicted intellectual disability increased hours spent caring by primary caregivers (p = 0.01-0.04), and neuropsychiatric comorbidities decreased family functioning (p = 0.02) and caregiver HRQL (p < 0.01).

CONCLUSION

These findings highlight the role of epileptic seizures and neuropsychiatric disorders in the considerable burden of TSC on primary caregivers and families.

Empowering Families Through Technology: A Mobile-Health Project to Reduce the TAND Identification and Treatment Gap (TANDem)

INTRODUCTION

Tuberous Sclerosis Complex (TSC) is a multi-system genetic disorder with various TSC-Associated Neuropsychiatric Disorders (TAND) that significantly impact the mental health and wellbeing of individuals with TSC and their caregivers. TAND represents the number one concern to families worldwide, yet is highly under-identified and under-treated. The clinician-administered TAND-Checklist (Lifetime version, TAND-L) has improved identification of TAND in clinical settings. However, many individuals with TSC and their caregivers still have difficulty accessing suitable support for diagnosis and evidence-informed interventions. The TANDem study is a community-based participatory research project with a broad range of TSC stakeholders aimed at reducing the TAND identification and treatment gap.

OBJECTIVES

Participatory research identified three priority next steps: 1) development and validation of a self-report, quantified version of the TAND Checklist (TAND-SQ) and building the TAND-SQ into a smartphone application, 2) generation of consensus clinical recommendations for the identification and treatment of TAND, to be incorporated as a TAND toolkit on the app, and 3) establishment of a global TAND consortium through networking, capacity-building and public engagement activities.

METHODS

TANDem is a four-year project, and includes 24 consortium members from 10 countries representing all World Health Organization regions. Collaborators represent five stakeholder groups (family representatives, technology experts, clinical experts, non-profit organisations and researchers). Here we outline the project study protocol in detail, describing the scientific rationale, the project aims and objectives, the methods involved in participant recruitment, multi-site and multi-phase data collection, data analysis, ethical considerations including informed consent, data protection, privacy and confidentiality considerations related to the European Union General Data Protection Regulation and the USA Health Insurance Portability and Accountability Act. The expected outcomes and potential impact on the TSC community, implementation and dissemination of results, as well as future scale-up and scale-out plans are also discussed.

CONCLUSIONS

The TANDem project has the potential to transform the global TSC community by empowering families living with TSC through an easily accessible digital solution to allow them to document their own TAND needs linked to an evidence-informed toolkit to enhance personalised healthcare, and by providing healthcare professionals with consensus clinical recommendations to prevent, identify and manage TAND manifestations.

Benign tumors in TSC are amenable to treatment by GD3 CAR T cells in mice

Mutations underlying disease in tuberous sclerosis complex (TSC) give rise to tumors with biallelic mutations in TSC1 or TSC2 and hyperactive mammalian target of rapamycin complex 1 (mTORC1). Benign tumors might exhibit de novo expression of immunogens, targetable by immunotherapy. As tumors may rely on ganglioside D3 (GD3) expression for mTORC1 activation and growth, we compared GD3 expression in tissues from patients with TSC and controls. GD3 was overexpressed in affected tissues from patients with TSC and also in aging Tsc2+/^– mice. As GD3 overexpression was not accompanied by marked natural immune responses to the target molecule, we performed preclinical studies with GD3 chimeric antigen receptor (CAR) T cells. Polyfunctional CAR T cells were cytotoxic toward GD3-overexpressing targets. In mice challenged with Tsc2^–/– tumor cells, CAR T cells substantially and durably reduced the tumor burden, correlating with increased T cell infiltration. We also treated aged Tsc2+/^– heterozygous (>60 weeks) mice that carry spontaneous Tsc2^–/– tumors with GD3 CAR or untransduced T cells and evaluated them at endpoint. Following CAR T cell treatment, the majority of mice were tumor free while all control animals carried tumors. The outcomes demonstrate a strong treatment effect and suggest that targeting GD3 can be successful in TSC.

Tumor Syndromes: Neurosurgical Evaluation and Management

There are multiple syndromes associated with tumors of the central nervous system (CNS). The most common CNS tumor syndrome is neurofibromatosis-1, with well-defined major and minor criteria needed for diagnosis. Other syndromes with variable degree of CNS and extra-CNS involvement that the neurosurgeon should be aware of include neurofibromatosis-2; Turcot syndrome; Cowden syndrome; Gorlin syndrome; Li-Fraumeni syndrome; ataxia-telangiectasia; multiple endocrine neoplasia type 1; von Hippel-Lindau syndrome; and tuberous sclerosis complex. Although most CNS tumor syndromes follow an autosomal dominant pattern of inheritance, the genetic underpinnings of each disease are complex and increasingly better understood.

Interleukin-6 mediates PSAT1 expression and serine metabolism in TSC2-deficient cells

Tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis (LAM) are caused by aberrant mechanistic Target of Rapamycin Complex 1 (mTORC1) activation due to loss of either TSC1 or TSC2 Cytokine profiling of TSC2-deficient LAM patient-derived cells revealed striking up-regulation of Interleukin-6 (IL-6). LAM patient plasma contained increased circulating IL-6 compared with healthy controls, and TSC2-deficient cells showed up-regulation of IL-6 transcription and secretion compared to wild-type cells. IL-6 blockade repressed the proliferation and migration of TSC2-deficient cells and reduced oxygen consumption and extracellular acidification. U-¹³C glucose tracing revealed that IL-6 knockout reduced 3-phosphoserine and serine production in TSC2-deficient cells, implicating IL-6 in de novo serine metabolism. IL-6 knockout reduced expression of phosphoserine aminotransferase 1 (PSAT1), an essential enzyme in serine biosynthesis. Importantly, recombinant IL-6 treatment rescued PSAT1 expression in the TSC2-deficient, IL-6 knockout clones selectively and had no effect on wild-type cells. Treatment with anti-IL-6 (αIL-6) antibody similarly reduced cell proliferation and migration and reduced renal tumors in Tsc2 ^+/- mice while reducing PSAT1 expression. These data reveal a mechanism through which IL-6 regulates serine biosynthesis, with potential relevance to the therapy of tumors with mTORC1 hyperactivity.

Whole Exome Sequencing in a Series of Patients with a Clinical Diagnosis of Tuberous Sclerosis Not Confirmed by Targeted TSC1/TSC2 Sequencing

BACKGROUND

Approximately fifteen percent of patients with tuberous sclerosis complex (TSC) phenotype do not have any genetic disease-causing mutations which could be responsible for the development of TSC. The lack of a proper diagnosis significantly affects the quality of life for these patients and their families.

METHODS

The aim of our study was to use Whole Exome Sequencing (WES) in order to identify the genes responsible for the phenotype of nine patients with clinical signs of TSC, but without confirmed tuberous sclerosis complex 1/ tuberous sclerosis complex 2 (TSC1/TSC2) mutations using routine molecular genetic diagnostic tools.

RESULTS

We found previously overlooked heterozygous nonsense mutations in TSC1, and a heterozygous intronic variant in TSC2. In one patient, two heterozygous missense variants were found in polycystic kidney and hepatic disease 1 (PKHD1), confirming polycystic kidney disease type 4. A heterozygous missense mutation in solute carrier family 12 member 5 (SLC12A5) was found in one patient, which is linked to cause susceptibility to idiopathic generalized epilepsy type 14. Heterozygous nonsense variant ring finger protein 213 (RNF213) was identified in one patient, which is associated with susceptibility to Moyamoya disease type 2. In the remaining three patients WES could not reveal any variants clinically relevant to the described phenotypes.

CONCLUSION

Patients without appropriate diagnosis due to the lack of sensitivity of the currently used routine diagnostic methods can significantly profit from the wider application of next generation sequencing technologies in order to identify genes and variants responsible for their symptoms.

Genetic and Environmental Contributions to Autism Spectrum Disorder Through Mechanistic Target of Rapamycin

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects an individual’s reciprocal social interaction and communication ability. Numerous genetic and environmental conditions are associated with ASD, including tuberous sclerosis complex, phosphatase and tensin homolog hamartoma tumor syndrome, fragile X syndrome, and neurofibromatosis 1. The pathogenic molecular mechanisms of these diseases are integrated into the hyperactivation of mTORC1 (mechanistic target of rapamycin complex 1). Rodent models of these diseases have shown high mTORC1 activity in the brain and ASD-related behavioral deficits, which were reversed by the mTORC1 inhibitor rapamycin. Environmental stress can also affect this signaling pathway. In utero exposure to valproate caused ASD in offspring and enhanced mTORC1 activity in the brain, which was sensitive to mTORC1 inhibition. mTORC1 is a signaling hub for diverse cellular functions, including protein synthesis, through the phosphorylation of its targets, such as ribosomal protein S6 kinases. Metabotropic glutamate receptor 5–mediated synaptic function is also affected by the dysregulation of mTORC1 activity, such as in fragile X syndrome and tuberous sclerosis complex. Reversing these downstream changes that are associated with mTORC1 activation normalizes behavioral defects in rodents. Despite abundant preclinical evidence, few clinical studies have investigated the treatment of ASD and cognitive deficits. Therapeutics other than mTORC1 inhibitors failed to show efficacy in fragile X syndrome and neurofibromatosis 1. mTORC1 inhibitors have been tested mainly in tuberous sclerosis complex, and their effects on ASD and neuropsychological deficits are promising. mTORC1 is a promising target for the pharmacological treatment of ASD associated with mTORC1 activation.

Tuberous sclerosis complex for the pulmonologist

Tuberous sclerosis complex (TSC) is a rare multisystem genetic disorder affecting almost all organs with no sex predominance. TSC has an autosomal-dominant inheritance and is caused by a heterozygous mutation in either the TSC1 or TSC2 gene leading to hyperactivation of the mammalian target of rapamycin (mTOR). TSC is associated with several pulmonary manifestations including lymphangioleiomyomatosis (LAM), multifocal micronodular pneumocyte hyperplasia (MMPH) and chylous effusions. LAM is a multisystem disorder characterised by cystic destruction of lung parenchyma, and may occur in either the setting of TSC (TSC-LAM) or sporadically (S-LAM). LAM occurs in 30–40% of adult females with TSC at childbearing age and is considered a nonmalignant metastatic neoplasm of unknown origin. TSC-LAM is generally milder and, unlike S-LAM, may occur in males. It manifests as multiple, bilateral, diffuse and thin-walled cysts with normal intervening lung parenchyma on chest computed tomography. LAM is complicated by spontaneous pneumothoraces in up to 70% of patients, with a high recurrence rate. mTOR inhibitors are the treatment of choice for LAM with moderately impaired lung function or chylous effusion. MMPH, manifesting as multiple solid and ground-glass nodules on high-resolution computed tomography, is usually harmless with no need for treatment.

Tuberous sclerosis complex is associated with diverse pulmonary manifestations including LAM, multiple micronodular pneumocyte hyperplasia and chylous effusions. LAM occurs in 30–40% of adult females with tuberous sclerosis complex.https://bit.ly/3iLqZ08

Direct and indirect costs and cost-driving factors of Tuberous sclerosis complex in children, adolescents, and caregivers: a multicenter cohort study

BACKGROUND

Tuberous sclerosis complex (TSC), a multisystem genetic disorder, affects many organs and systems, characterized by benign growths. This German multicenter study estimated the disease-specific costs and cost-driving factors associated with various organ manifestations in TSC patients.

METHODS

A validated, three-month, retrospective questionnaire was administered to assess the sociodemographic and clinical characteristics, organ manifestations, direct, indirect, out-of-pocket, and nursing care-level costs, completed by caregivers of patients with TSC throughout Germany.

RESULTS

The caregivers of 184 patients (mean age 9.8 ± 5.3 years, range 0.7-21.8 years) submitted questionnaires. The reported TSC disease manifestations included epilepsy (92%), skin disorders (86%), structural brain disorders (83%), heart and circulatory system disorders (67%), kidney and urinary tract disorders (53%), and psychiatric disorders (51%). Genetic variations in TSC2 were reported in 46% of patients, whereas 14% were reported in TSC1. Mean total direct health care costs were EUR 4949 [95% confidence interval (95% CI) EUR 4088-5863, median EUR 2062] per patient over three months. Medication costs represented the largest direct cost category (54% of total direct costs, mean EUR 2658), with mechanistic target of rapamycin (mTOR) inhibitors representing the largest share (47%, EUR 2309). The cost of anti-seizure drugs (ASDs) accounted for a mean of only EUR 260 (5%). Inpatient costs (21%, EUR 1027) and ancillary therapy costs (8%, EUR 407) were also important direct cost components. The mean nursing care-level costs were EUR 1163 (95% CI EUR 1027-1314, median EUR 1635) over three months. Total indirect costs totaled a mean of EUR 2813 (95% CI EUR 2221-3394, median EUR 215) for mothers and EUR 372 (95% CI EUR 193-586, median EUR 0) for fathers. Multiple regression analyses revealed polytherapy with two or more ASDs and the use of mTOR inhibitors as independent cost-driving factors of total direct costs. Disability and psychiatric disease were independent cost-driving factors for total indirect costs as well as for nursing care-level costs.

CONCLUSIONS

This study revealed substantial direct (including medication), nursing care-level, and indirect costs associated with TSC over three months, highlighting the spectrum of organ manifestations and their treatment needs in the German healthcare setting.

TRIAL REGISTRATION

DRKS, DRKS00016045. Registered 01 March 2019, http://www.drks.de/DRKS00016045.

Predictors and Long-term Outcome of Resective Epilepsy Surgery in Patients with Tuberous Sclerosis Complex: A Single-centre Retrospective Cohort Study

OBJECTIVE

To identify prognostic factors and long-term seizure outcomes for patients with tuberous sclerosis complex (TSC) who underwent resective treatment for epilepsy.

METHODS

We enrolled 81 patients with TSC who had undergone resective epilepsy surgery at Sanbo Brain Hospital, Capital Medical University, between April 2004 and June 2019. We estimated cumulative probability of remaining seizure-free and plotted survival curves. Variables were compared using Mann-Whitney U, Pearson's correlation, continuity correction, and Fisher's exact chi-square tests. Prognostic predictors were analysed using log-rank (Mantel-Cox) tests and Cox regression models.

RESULTS

At the last follow-up, 48 (59.3%) patients were classified as International League Against Epilepsy Class 1 (including 14 patients who had seizures <3 times postoperatively on the same or different day and were seizure-free at all other times). The estimated cumulative probability of remaining seizure-free postoperatively was 69.0% (95% confidence interval [CI] 58.8-79.2%), 61.9% (95% CI 51.1-72.7%), and 55.0% (95% CI 42.8-67.2%) at 2, 5, and 10 years, respectively. The mean time of remaining seizure-free was 7.24 ± 0.634 years (95% CI 6.00-8.49); en bloc resection was an essential positive predictor of postoperative seizure freedom, as was age at seizure onset, regional interictal video-electroencephalography pattern, and temporal lobe surgery. The longer the seizure-free time, the less likely a relapse. Patients who postoperatively experienced seizures remained likely to recover.

CONCLUSIONS

We demonstrated the efficacy of surgical treatment for patients with TSC and intractable epilepsy. Detailed perioperative tests are a reliable predictor of postoperative seizure freedom.

Economic burden associated with tuberous sclerosis complex in patients with epilepsy

OBJECTIVES

Data on the economic burden associated with tuberous sclerosis complex (TSC) among patients with epilepsy in the United States (US) are limited. This study aimed to assess all-cause and epilepsy-related healthcare resource utilization (HRU) and healthcare costs in the US among patients with epilepsy and TSC compared with patients with epilepsy but without TSC.

METHODS

This retrospective study was conducted using the Symphony Health Solutions claims database (April 1, 2017-June 30, 2019). Patients with ≥1 medical claim with a diagnosis code representing epilepsy or seizures were assigned to the cohort with TSC if they had ≥1 medical claim for TSC; the remaining patients were assigned to the cohort without TSC. Patients in the cohort with TSC were exactly matched 1:5 on demographics to patients in the cohort without TSC. All-cause and epilepsy-related HRU, medical charges, prescription drug costs, and the use of antiepileptic drugs (AEDs) were compared between the matched cohorts over the 1-year study period.

RESULTS

A total of 2028 patients with epilepsy and TSC were matched to 10,140 patients with epilepsy but without TSC. Patients with TSC were more likely to have a diagnosis code for refractory epilepsy (38.7% vs. 10.2%, p < 0.001) and more likely to have used an AED (89.5% vs. 71.2%, p < 0.001) than patients without TSC over the study period. On average, patients with TSC received 2.1 distinct AEDs versus 1.3 distinct AEDs among patients without TSC. Compared with patients without TSC, patients with TSC had numerically but not statistically higher incidence rates of all-cause outpatient, clinic, office, and other visits; significantly lower rates of all-cause inpatient and emergency room visits (p < 0.001); and statistically significantly higher incidence rates of epilepsy-related outpatient, inpatient, office, and other visits (p ≤ 0.001). All-cause prescription drug costs were significantly higher among patients with TSC than patients without TSC (cost difference per patient: $14,179, p < 0.001). All-cause medical service charges were numerically higher for patients with TSC, but the differences were not statistically significant (charge difference per patient: $4293 for medical services, p = 0.707). Epilepsy-related costs were significantly higher for patients with TSC; the cost difference per patient was $14,639 for prescription costs (p < 0.001), and the charge difference per patient was $16,838 for medical charges (p = 0.019).

CONCLUSION

The results of this study underscore the high epilepsy-related HRU and costs incurred by patients with epilepsy and TSC relative to those incurred by patients with epilepsy but without TSC.

Current trends in the management of subependymal giant cell astrocytomas in tuberous sclerosis

INTRODUCTION

The management of subependymal giant cells astrocytomas (SEGAs) has been traditionally represented by surgical treatment through an open craniotomic approach. Though open surgery still represents a major option in the management of this kind of tumors, the introduction of mTOR inhibitors in the clinical practice, technological advances in neuroendoscopy and the more recent use of laser interstitial therapy have significantly enlarged the range of available management opportunities.

METHODS

A thorough review of the literature has been performed. Accordingly, current views in open surgical treatment, medical therapy, endoscopic tumor removal and new trends (such as laser interstitial thermal therapy) are discussed.

RESULTS

The risk of significant neurological morbidity (5-50%) complicating open surgery has been for a long time representing a main drawback in the management of SEGAs. More recent series report a significant reduction of morbidity and mortality. The mTOR inhibitors have demonstrated efficacy in both warranting a tumor reduction by up to 60% of the tumor size and helping the control of seizures. However, the reported rate of side effects is as high as 30% and tumor recurrence is a documented occurrence at the time of mTOR inhibitor discontinuation. Endoscopic tumor removal has been more extensively considered an option due to the acquisition of new tools. Limits are still represented by tumor size (< 3 cm) and broad attachment of the tumor to the basal ganglia. Laser interstitial thermal therapy (LITT) is the more recently considered option. Though promising, only short follow-up is available so far, while data on medium- and long-term results of this treatment are completely lacking to date.

CONCLUSIONS

Surgical treatment remains a mainstay of the management of SEGAs. The indication for an open craniotomic approach should be balanced with an endoscopic tumor removal or LITT according to patient conditions, presence or not of an active hydrocephalus and extension of the attachment of the tumor to the basal ganglia. The mTOR inhibitors do have a definite role both as primary and as adjuvant treatment, but consistent limitations are represented up to now by a not negligible rate of complications and the uncertainties related to the possibility of tumor recurrence once the medical treatment is discontinued.

Prevalence, mortality and healthcare economic burden of tuberous sclerosis in Hong Kong: a population-based retrospective cohort study (1995-2018)

Background

We aim to elucidate the disease impact by accounting the prevalence, survival rate, genetics, mTOR inhibitor use and direct costs of tuberous sclerosis complex (TSC) in our local setting. TSC patients with documented visits to our local public hospitals in 1995–2018 were identified. The public hospitals captured most if not all local TSC patients. Demographics such as age, sex, death, genetic profiles were retrieved from the central electronic database. Data including prevalence, age distribution and survival rate were analysed. Direct cost was calculated with reference to the drug use and number of visits to various public hospital facilities.

Results

We identified 284 surviving TSC patients (55.3% male) in Hong Kong. The age range was from 4.5 months to 89.9 years, with a median age of 27.2 years. Paediatrics (< 18 years) to adult (≥18 years) ratio was 1:2.84. The overall prevalence of TSC patients was 3.87 in 100,000 (i.e. 1 in 25,833). Genetically, TSC1:TSC2 ratio is 1:2.7.

Thirty seven patients died within the study period. The age of death ranged from 7.6 years to 77.8 years, with a median age of death at 36.6 years (IQR: 24.7–51.1 years). Most patients survived till adulthood. Survival rate at 20 and 50 years follow-up was 98.6 and 79.5% respectively.

Two hundred and twenty nine TSC patients (71.3%) had neurological manifestations, sixteen patients (5.0%) had chronic kidney diseases and five patients (1.6%) had pulmonary lymphangioleiomyomatosis. Forty seven (16.5%) TSC patients were prescribed with mTOR inhibitors within the study period. Healthcare facility utilization was further analysed in the 2008–2018 cohort. In particular, the mean number of specialist out-patient clinic visits per patient-year was 9.23 per patient-year, which was 4.91 times more than that of local general population.

Conclusions

Prevalence of local TSC patients is within the range of that reported in the literature. Local TSC patients have fair long term survival, but they require disproportionally high healthcare cost when compared with the general population, particularly in terms of outpatient (OP) visits. Although effective disease-modifying agent (i.e. mTOR inhibitor) is available, it was not widely used yet in Hong Kong despite the fact that Government approved and supported its use recently. Further research on quality of life and setting up a comprehensive patient registry are necessary for more accurate assessment of cost and benefit.

Mutation landscape of TSC1/TSC2 in Chinese patients with tuberous sclerosis complex

Genetic testing of TSC1 and TSC2 is important for the diagnosis of tuberous sclerosis complex (TSC), an autosomal dominant neurocutaneous disease. This study retrospectively reviewed 347 samples from patients with clinically suspected TSC being tested for mutations in TSC1 and TSC2 genes using next-generation sequencing and multiplex ligation-dependent probe amplification. Two hundred eighty-one patients (80.98%) were classified as definite/possible/uncertain diagnosis of TSC and the mutational spectrum of TSC1/TSC2 was described. Two hundred eighteen unique nonsynonymous SNVs/Indels (64 in TSC1, 154 in TSC2) and 13 copy number variants (CNVs) were identified in 241 samples (85.77%), including 82 novel variants. CNVs involving 12 large deletions and one duplication were detected exclusively in TSC2. Both TSC1 and TSC2 mutations were nearly uniformly distributed in their protein-coding regions. Furthermore, a string of non-TSC1/TSC2 deleterious variants in 12 genes was identified in the patients, especially overwhelmingly present in the patients with no mutation identified (NMI) in TSC1/TSC2. Our study provides a comprehensive TSC1/TSC2 mutation landscape and reveal some potential risk non-TSCs variants present in patients with NMI.

Natural clusters of tuberous sclerosis complex (TSC)-associated neuropsychiatric disorders (TAND): new findings from the TOSCA TAND research project

Background

Tuberous sclerosis complex (TSC)-associated neuropsychiatric disorders (TAND) have unique, individual patterns that pose significant challenges for diagnosis, psycho-education, and intervention planning. A recent study suggested that it may be feasible to use TAND Checklist data and data-driven methods to generate natural TAND clusters. However, the study had a small sample size and data from only two countries. Here, we investigated the replicability of identifying natural TAND clusters from a larger and more diverse sample from the TOSCA study.

Methods

As part of the TOSCA international TSC registry study, this embedded research project collected TAND Checklist data from individuals with TSC. Correlation coefficients were calculated for TAND variables to generate a correlation matrix. Hierarchical cluster and factor analysis methods were used for data reduction and identification of natural TAND clusters.

Results

A total of 85 individuals with TSC (female:male, 40:45) from 7 countries were enrolled. Cluster analysis grouped the TAND variables into 6 clusters: a scholastic cluster (reading, writing, spelling, mathematics, visuo-spatial difficulties, disorientation), a hyperactive/impulsive cluster (hyperactivity, impulsivity, self-injurious behavior), a mood/anxiety cluster (anxiety, depressed mood, sleep difficulties, shyness), a neuropsychological cluster (attention/concentration difficulties, memory, attention, dual/multi-tasking, executive skills deficits), a dysregulated behavior cluster (mood swings, aggressive outbursts, temper tantrums), and an autism spectrum disorder (ASD)-like cluster (delayed language, poor eye contact, repetitive behaviors, unusual use of language, inflexibility, difficulties associated with eating). The natural clusters mapped reasonably well onto the six-factor solution generated. Comparison between cluster and factor solutions from this study and the earlier feasibility study showed significant similarity, particularly in cluster solutions.

Conclusions

Results from this TOSCA research project in an independent international data set showed that the combination of cluster analysis and factor analysis may be able to identify clinically meaningful natural TAND clusters. Findings were remarkably similar to those identified in the earlier feasibility study, supporting the potential robustness of these natural TAND clusters. Further steps should include examination of larger samples, investigation of internal consistency, and evaluation of the robustness of the proposed natural clusters.

Burden of Illness and Quality of Life in Tuberous Sclerosis Complex: Findings From the TOSCA Study

Research on tuberous sclerosis complex (TSC) to date has focused mainly on the physical manifestations of the disease. In contrast, the psychosocial impact of TSC has received far less attention. The aim of this study was therefore to examine the impact of TSC on health, quality of life (QoL), and psychosocial well-being of individuals with TSC and their families. Questionnaires with disease-specific questions on burden of illness (BOI) and validated QoL questionnaires were used. After completion of additional informed consent, we included 143 individuals who participated in the TOSCA (TuberOus SClerosis registry to increase disease Awareness) study. Our results highlighted the substantial burden of TSC on the personal lives of individuals with TSC and their families. Nearly half of the patients experienced negative progress in their education or career due to TSC (42.1%), as well as many of their caregivers (17.6% employed; 58.8% unemployed). Most caregivers (76.5%) indicated that TSC affected family life, and social and working relationships. Further, well-coordinated care was lacking: a smooth transition from pediatric to adult care was mentioned by only 36.8% of adult patients, and financial, social, and psychological support in 21.1, 0, and 7.9%, respectively. In addition, the moderate rates of pain/discomfort (35%) and anxiety/depression (43.4%) reported across all ages and levels of disease demonstrate the high BOI and low QoL in this vulnerable population.

Mutational analysis of TSC1 and TSC2 in Danish patients with tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by hamartomas in the skin and other organs, including brain, heart, lung, kidney and bones. TSC is caused by mutations in TSC1 and TSC2. Here, we present the TSC1 and TSC2 variants identified in 168 Danish individuals out of a cohort of 327 individuals suspected of TSC. A total of 137 predicted pathogenic or likely pathogenic variants were identified: 33 different TSC1 variants in 42 patients, and 104 different TSC2 variants in 126 patients. In 40 cases (24%), the identified predicted pathogenic variant had not been described previously. In total, 33 novel variants in TSC2 and 7 novel variants in TSC1 were identified. To assist in the classification of 11 TSC2 variants, we investigated the effects of these variants in an in vitro functional assay. Based on the functional results, as well as population and genetic data, we classified 8 variants as likely to be pathogenic and 3 as likely to be benign.

Impacting development in infants with tuberous sclerosis complex: Multidisciplinary research collaboration

The Tuberous Sclerosis Complex Autism Center of Excellence Network (TACERN) is a 6-site collaborative conducting longitudinal research on infants with tuberous sclerosis complex (TSC), focused on identifying early biomarkers for autism spectrum disorder (ASD). A multidisciplinary research team that includes the specialties of psychology, neurology, pediatrics, medical genetics, and speech-language pathology, its members work together to conduct studies on neurological status, brain structure and function, neurodevelopmental phenotype, and behavioral challenges in this population. This article provides insights into the roles of the multidisciplinary multisite team and lessons learned from the collaboration, in terms of research as well as training of future researchers and clinicians. In addition, the authors detail the major findings to date, including those related to the identification and measurement of early symptoms of ASD, relationship between seizures and early development, and early biomarkers for epilepsy and developmental delay in infants and young children with TSC. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Counselling in tuberous sclerosis complex: A survey on content and satisfaction in the Netherlands

BACKGROUND

Tuberous sclerosis complex (TSC) is a highly variable condition and its clinical features cannot reliably be predicted from the genotype. Counselling of parents of a child with TSC is challenging because of the variability of the condition and the changing outlook due to new treatment options. This study explored current counselling strategies in TSC in the Netherlands, with the aim of developing a recommendation for counselling.

METHOD

We performed a nationwide survey using digital questionnaires. Questionnaires were sent to parents of children diagnosed with TSC, and to medical doctors involved in counselling, both no more than ten years prior to the study. Questions focused on general information about the child with TSC, medical doctors involved in counselling, type of information provided, mode of providing information, and recommendations for improvement of counselling.

RESULTS

Parents of 34 children diagnosed with TSC (7 prenatally) and 18 medical doctors from different departments responded to the questionnaires. Almost all parents were informed on the neurological and cardiac symptoms of TSC, other symptoms were mentioned less often. Satisfaction on counselling was higher when more information on the variability of TSC was provided, preferentially during a clinical visit, when emotional support was provided, and when parents were notified of the TSC patient society.

CONCLUSIONS

Information on the variability in expression and quality of life is highly demanded by (expecting) parents of a child with TSC. Furthermore, reference should be made to institutions such as the support organisation for patients and social services for questions and support.

A systematic review on the burden of illness in individuals with tuberous sclerosis complex (TSC)

Objective

This review will summarize current knowledge on the burden of illness (BOI) in tuberous sclerosis complex (TSC), a multisystem genetic disorder manifesting with hamartomas throughout the body, including mainly the kidneys, brain, skin, eyes, heart, and lungs.

Methods

We performed a systematic analysis of the available literature on BOI in TSC according to the PRISMA guidelines. All studies irrespective of participant age that reported on individual and societal measures of disease burden (e.g. health care resource use, costs, quality of life) were included.

Results

We identified 33 studies reporting BOI in TSC patients. Most studies (21) reported health care resource use, while 14 studies reported quality of life and 10 studies mentioned costs associated with TSC. Only eight research papers reported caregiver BOI. Substantial BOI occurs from most manifestations of the disorder, particularly from pharmacoresistant epilepsy, neuropsychiatric, renal and skin manifestations. While less frequent, pulmonary complications also lead to a high individual BOI. The range for the mean annual direct costs varied widely between 424 and 98,008 International Dollar purchasing power parities (PPP-$). Brain surgery, end-stage renal disease with dialysis, and pulmonary complications all incur particularly high costs. There is a dearth of information regarding indirect costs in TSC. Mortality overall is increased compared to general population; and most TSC related deaths occur as a result of complications from seizures as well as renal complications. Long term studies report mortality between 4.8 and 8.3% for a follow-up of 8 to 17.4 years.

Conclusions

TSC patients and their caregivers have a high burden of illness, and TSC patients incur high costs in health care systems. At the same time, the provision of inadequate treatment that does not adhere to published guidelines is common and centralized TSC care is received by no more than half of individuals who need it, especially adults. Further studies focusing on the cost effectiveness and BOI outcomes of coordinated TSC care as well as of new treatment options such as mTOR inhibitors are necessary.

Quality of life of children with tuberous sclerosis complex

AIM

Evaluation of impaired quality of life (QOL) of Malaysian children with tuberous sclerosis complex (TSC) and its possible risk factors.

METHOD

Cross-sectional study on 68 parents of Malaysian children aged 2-18 years with TSC. QOL was assessed using proxy-report Paediatric Quality of Life Inventory (PedsQL) V.4.0, and scores compared with those from a previous cohort of healthy children. Parents also completed questionnaires on child behaviour (child behaviour checklist (CBCL)) and parenting stress (parenting stress index-short form). Multiple regression analysis was used to determine sociodemographic, medical, parenting stress and behavioural factors that impacted on QOL.

RESULTS

The mean proxy-report PedsQL V.4.0 total scale score, physical health summary score and psychosocial health summary score of the patients were 60.6 (SD 20.11), 65.9 (SD 28.05) and 57.8 (SD 19.48), respectively. Compared with healthy children, TSC patients had significantly lower mean PedsQL V.4.0 total scale, physical health and psychosocial health summary scores (mean difference (95% CI): 24 (18-29), 20 (12-27) and 26 (21-31) respectively). Lower total scale scores were associated with clinically significant CBCL internalising behaviour scores, age 8-18 years and Chinese ethnicity. Lower psychosocial health summary scale scores were associated with clinically significant CBCL internalising behaviour scores, Chinese ethnicity or >1 antiepileptic drug (AED).

CONCLUSION

Parents of children with TSC reported lower PedsQL V.4.0 QOL scores in all domains, with psychosocial health most affected. Older children, those with internalising behaviour problems, of Chinese ethnicity or on >1 AED was at higher risk of lower QOL. Clinicians need to be vigilant of QOL needs among children with TSC particularly with these additional risk factors.

Resting-State fMRI Networks in Children with Tuberous Sclerosis Complex

BACKGROUND AND PURPOSE

There are no published studies examining resting state networks (RSNs) and their relationship with neurodevelopmental metrics in tuberous sclerosis complex (TSC). We aimed to identify major resting-state functional magnetic resonance imaging (rs-fMRI) networks in infants with TSC and correlate network analyses with neurodevelopmental assessments, autism diagnosis, and seizure history.

METHODS

Rs-fMRI data from 34 infants with TSC, sedated with propofol during the scan, were analyzed to identify auditory, motor, and visual RSNs. We examined the correlations between auditory, motor, and visual RSNs at approximately 11.5 months, neurodevelopmental outcome at approximately 18.5 months, and diagnosis of autism spectrum disorders at approximately 36 months of age.

RESULTS

RSNs were obtained in 76.5% (26/34) of infants. We observed significant negative correlations between auditory RSN and auditory comprehension test scores (p = .038; r = -.435), as well as significant positive correlations between motor RSN and gross motor skills test scores (p = .023; r = .564). Significant positive correlations between motor RSNs and gross motor skills (p = .012; r = .754) were observed in TSC infants without autism, but not in TSC infants with autism, which could suggest altered motor processing. There were no significant differences in RSNs according to seizure history.

CONCLUSIONS

Negative correlation between auditory RSN, as well as positive correlation between motor RSN and developmental outcome measures might reflect different brain mechanisms and, when identified, may be helpful in predicting later function. A larger study of TSC patients with a healthy control group is needed before auditory and motor RSNs could be considered as neurodevelopmental outcome biomarkers.

Severe Hypocalcemia in a Patient with Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder affecting multiple organs, including the brain, skin, lung, and kidney. Among the multiple comorbidities in TSC, bone mineral disturbances remain relatively unrecognized, and only a few studies have reported alteration in calcium homeostasis. Hypocalcemia is a serious medical condition in patients with TSC who are at high risk for seizures. Therefore, hypocalcemia should be thoroughly evaluated by obtaining a history of associated medication use and measuring vitamin D levels. Here, we report the case of a patient with TSC who presented with severe hypocalcemia which may have been related to a history of anticonvulsant use and a recent decline in kidney function, and was successfully treated with calcium and vitamin D replacement.

A step-wise approach for establishing a multidisciplinary team for the management of tuberous sclerosis complex: a Delphi consensus report

Background

Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disorder associated with mutations in TSC1 and TSC2 genes, upregulation of mammalian target of rapamycin signaling, and subsequent tumor formation in various organs. Due to the many manifestations of TSC and their potential complications, management requires the expertise of multiple medical disciplines. A multidisciplinary care approach is recommended by consensus guidelines. Use of multidisciplinary teams (MDTs) has been shown to be beneficial in treating other complex diseases, such as cancer. In a lifelong disease such as TSC, an MDT may facilitate the transition from pediatric to adult care. However, little guidance exists in the literature regarding how to organize an MDT in TSC.

Methods

To discuss the best approach to assembling an MDT, this project was initiated in October 2017 with a meeting of 12 physicians from various specialties and various countries. Following this first meeting, the experts generated statements on the most important aspects to implement in establishing an MDT for TSC by 3 rounds of selection using a Delphi process via electronic correspondence. Finally, TSC patient advocates reviewed the findings and provided additional insights from a patient perspective.

Results

A 3-step roadmap was recommended, starting with identifying a single individual to begin organizing care (Step 1), then establishing a small core team (Step 2), and finally, establishing a larger multi-disciplinary team (Step 3). Because of the multisystemic nature of TSC, the MDT should include specialists such as a neurologist, a neurosurgeon, a nephrologist, a urologist, a pulmonologist, an ophthalmologist, a cardiologist, a dermatologist, a geneticist, and a psychiatrist/psychologist. The MDT should recommend a care plan for each patient based on the individual’s needs and in consultation with him/her or his/her family. Some of the most important aspects of an MDT that were agreed upon included identifying a case manager to help coordinate care, providing access to health care professionals of varying specialties, and including a lead physician who takes medical responsibility for patients’ overall care.

Conclusions

The results of our consensus provide guidance to support the initiation of an MDT in TSC.

Health utilities and quality of life in individuals with tuberous sclerosis complex (TSC) who experience epileptic seizures: A web-based survey

OBJECTIVES

Individuals with tuberous sclerosis complex (TSC) experience a wide range of health impacts, including epileptic seizures, negatively impacting their health-related quality of life (HRQoL). Health state utility values (HSUVs) are index values representing HRQoL and are used as key inputs for health economic analyses. Such data are currently very limited in the TSC population. The objective of this study was to generate HSUVs for TSC health states, defined by the number and type of seizures experienced in the previous week, and to compare with UK normative values.

METHODS

This cross-sectional study involved 186 participants (individuals with TSC = 61, caregivers reporting for individuals with TSC = 125) from Europe and North America who completed a web-based survey. Participants completed the [EuroQol - 5 dimensions - 3 levels] (self-report version for individuals with TSC or proxy version 1 for caregivers).

RESULTS

The mean age of individuals with TSC was 27.3 years (self-reported: 41.3 years, caregiver-reported: 20.5 years); 56% were males. Most individuals with TSC (71%) reported experiencing between one and ten seizures in the week prior to participating in the study. The most frequently reported type of seizure was focal: simple partial (50%). Across all participants (combined self-report and caregiver-report), the mean HSUV was 0.474 (95% confidence interval [CI]: 0.424-0.524), significantly lower than the UK norm (0.856, 95%CI: 0.848-0.864) [1]. Mean HSUV and HRQoL scores were consistently lower when reported by caregivers than when self-reported by individuals with TSC (HSUV = 0.351 vs. 0.727). This is in part because caregivers reported for individuals with TSC who experienced more frequent and severe seizures than those who were able to self-report. HSUVs incrementally decreased with the experience of more frequent (1-5 per week: HSUV = 0.666 vs. >20: HSUV = 0.290) and more severe seizures (focal: simple partial: HSUV = 0.450 vs. generalized: convulsive: HSUV = 0.194).

CONCLUSIONS

The HRQoL and HSUV index scores indicate substantial impairment among individuals with TSC; HSUVs were shown to decrease considerably with increases in seizure frequency or seizure severity, indicating that more burdensome seizure health states are associated with poorer HRQoL.

Factors affecting epilepsy prognosis in patients with tuberous sclerosis

PURPOSE

We aimed to determine the characteristics of epileptic seizures that significantly affect the cognitive functions of 83 patients followed with tuberous sclerosis complex (TSC), their resistance to treatment and risk factors causing this resistance.

MATERIALS-METHODS

In order to determine the prognosis, the seizure-free/seizure-controlled group and the group with refractory seizures were compared. In addition, risk factors affecting cognitive functions in the patients were determined.

RESULTS

There was a statistical significance between the presence of a history of seizures in the neonatal period, the age of onset of seizures being less than 2 years of age, autism, status epilepticus, Lennox-Gastaut syndrome (LGS), presence of infantile spasm, generalization of the electroencephalography (EEG) findings, the number of tubers in cerebral imaging being more than three and refractory seizures (p < 0.05). Statistically significant relationship was found between presence of a history of seizures in the neonatal period, the age of onset of seizures, autism, LGS, presence of infantile spasm, presence of status epilepticus history, history of using more than three antiepileptic drugs, generalization of EEG findings, presence of SEGA in cerebral imaging, number of tubers being more than three and the patient's mental retardation (p < 0.05).

CONCLUSION

In logistic regression analysis, the age of the seizure onset being less than 2 years of age, the presence of autism and number of tubers being more than three in cerebral magnetic resonance imaging (MRI) are determined to be the risk factors that most likely to increase the seizures to be more resistant.

The Impact of Psychiatric Symptoms on Tuberous Sclerosis Complex and Utilization of Mental Health Treatment

BACKGROUND

Tuberous sclerosis complex (TSC) is a multisystem, neurocutaneous disorder with a spectrum of TSC-associated neuropsychiatric disorders. The most common neuropsychiatric manifestations in the pediatric and adult populations are cognitive concerns, depression, and anxiety. Previous research suggests that while 90% of individuals with TSC have some TSC-associated neuropsychiatric disorders features, only 20% receive treatment, leading to a 70% treatment gap.

METHODS

This web-based study used validated measures in conjunction with researcher-designed questions to evaluate perception of disease severity, presence of anxiety and depression, and the utilization and barriers toward mental health services among adults with TSC.

RESULTS

The Beck Anxiety Inventory, Beck Depression Inventory-II, and Brief Illness Perception Questionnaire indicated that our overall study population had mild symptoms of anxiety, minimal depression, and a moderate perception of disease severity. Notably, the difference between the median depression score for men and women was statistically significant with men scoring higher than women (P = 0.02). Of 69 respondents, 57% (n = 39) reported receiving mental health treatment at some point over their lifetime. In both the mental health treatment group and the nonmental health treatment group, cost was more often indicated as a barrier to accessing mental health resources (treatment group: cost = 51% and stigma = 21%; nontreatment group: cost = 27% and stigma = 20%).

CONCLUSIONS

TSC disease severity had a moderate and low-moderate association with anxiety and depression, respectively. Regardless of past utilization, respondents had a positive outlook towards the use of mental health services with the major barrier being cost.

Lymphangioleiomyomatosis (LAM) presenting as recurrent pneumothorax in an infant with tuberous sclerosis: treated successfully with sirolimus

Lymphangioleiomyomatosis (LAM) either sporadic or a part of tuberous sclerosis complex is rare in paediatric age group. Here, we report a case of LAM with tuberous sclerosis in an infant. She was referred to our institute at the age of 4 months as a case of recurrent bilateral pneumothorax requiring intercostal tube drainage. Detailed history revealed that patient was symptomatic since 1 month of age in the form of seizures. She had respiratory symptoms for last 15 days. General physical examination revealed whitish macular patches. Brain imaging was suggestive of cortical tubers and subependymal nodules. The echocardiography showed right atrial rhabdomyoma. Chest CT revealed multiple cysts suggesting LAM. On the basis of above findings, a diagnosis of tuberous sclerosis complex with LAM was made. The infant was started on sirolimus and there was significant clinical and radiological improvement over a period of 2 and half years without any side effects.

Economic burden, work, and school productivity in individuals with tuberous sclerosis and their families

AIMS

Tuberous sclerosis complex (TSC) is a multi-organ autosomal-dominant, genetic disorder with incomplete penetrance. The multiple manifestations of TSC and impacts to numerous organ systems represent significant disease, healthcare, and treatment burden. The economic and employment burden of the disease on individuals and their families is poorly understood. This study assessed the cost of illness and work and school productivity burden associated with TSC in a cross-sectional web-survey sample.

MATERIALS AND METHODS

Eligible TSC individuals and caregivers were invited through the Tuberous Sclerosis Alliance advocacy group to complete a web-based survey about illness characteristics, treatment, disease burden, direct and indirect healthcare costs, work and school impairment.

RESULTS

Data from 609 TSC adults or caregiver respondents with no cognitive impairments were analyzed. TSC adults (>18 years of age) had significantly higher direct out-of-pocket costs for ER visits, expenses for medical tests and procedures, alternative treatments, medications and lifetime cost of surgeries compared to TSC pediatric individuals. Both TSC adults and TSC caregivers reported work and school absenteeism and presenteeism; however, adults reported significantly higher absenteeism and presenteeism and overall activity impairment due to TSC, as might be expected, compared to TSC caregivers. TSC adults had significantly higher absenteeism and presenteeism rates compared to adults with moderate-to-severe plaque psoriasis and muscular sclerosis.

CONCLUSIONS

TSC results in considerable direct out-of-pocket medical costs and impairment to work productivity, especially for adults. Future studies should include the comparator group and examine direct cost burden in the US using electronic medical records and insurance databases.

A clinical update on tuberous sclerosis complex-associated neuropsychiatric disorders (TAND)

Tuberous sclerosis complex (TSC) is associated with a wide range of behavioral, psychiatric, intellectual, academic, neuropsychological, and psychosocial difficulties, which are often underdiagnosed and undertreated. Here, we present a clinical update on TSC-associated neuropsychiatric disorders, abbreviated as "TAND," to guide screening, diagnosis, and treatment in practice. The review is aimed at clinical geneticists, genetic counselors, pediatricians, and all generalists involved in the assessment and treatment of children, adolescents and adults with TSC, and related disorders. The review starts with a summary of the construct and levels of TAND, before presenting up-to-date information about each level of investigation. The review concludes with a synopsis of current and future TAND research.

Burden of renal angiomyolipomas associated with tuberous sclerosis complex: results of a patient and caregiver survey

Background

Tuberous sclerosis complex (TSC) is a rare genetic disorder characterized by benign tumors in multiple organs, including non-cancerous kidney lesions known as renal angiomyolipomas. This study’s objective is to describe the age-stratified morbidity, treatment patterns, and health-related quality of life of TSC patients with renal angiomyolipomas in the United States. A cross-sectional, anonymous web-based survey was conducted with a convenience sample of TSC patients and caregivers identified through a patient advocacy organization.

Results

Out of the total sample of 676, 182 respondents reported having kidney complications with 33% of the pediatric group and 25% of the adult group with TSC reporting them. Of those with kidney complications, 110 (60%) reported a diagnosis of renal angiomyolipomas, of which 79 (72%) were adult patients and 31 (28%) were pediatric age patients. Eighty-four percent of the pediatric group and 76% of the adult group reported lesions on both kidneys. Of the patients experiencing involvement of only one kidney, 60% of the pediatric group and 21% of the adult group reported having multiple tumors within the affected kidney. Almost all of the sample (99%) reported seeing a physician and having a procedure or test for TSC in the past year. Less than half the respondents (44%) reported being hospitalized in the past year. Thirty-nine percent reported an emergency room visit as well. Compared to scores for patients with kidney disease, the angiomyolipoma adult patients reported significantly lower Mental Component Summary scores on the SF-12.

Conclusions

Renal angiomyolipomas burden leads to frequent healthcare resource use including hospitalization, invasive treatments, and surgical procedures, which result in an impaired mental health related quality of life.

Familial genetic tuberous sclerosis complex associated with bilateral giant renal angiomyolipoma: A case report

Tuberous sclerosis complex (TSC) is an autosomal dominant disease involving multiple organs, but there are a limited number of reports on family TSC. In the present report, a case of a 52-year-old female with a familial genetic TSC, associated with bilateral giant renal angiomyolipoma, was described. The mother, second elder brother and daughter of the patient all exhibited TSC, but the clinical manifestations, and therapeutic prognosis between the family members were not the same. The present case report aimed at identifying an effective diagnostic method and treatment through additional study of familial genetic TSC, in order to prolong and improve the quality of life for patients with TSC. According to the present case and relevant literature reviews, it is suggested that fetal gene detection during pregnancy could prevent the passing of this disease onto further generations. Furthermore, early application of drug treatment may control the development of the disease in diagnosed patients. The combination of classical treatments with a small dose of mammalian target of rapamycin inhibitors is the typical recommendation, which may control the development of the disease more effectively and decrease adverse side-effects.

Outcome of childhood-onset epilepsy from adolescence to adulthood: Transition issues

This is the second of three papers that summarize the second symposium on Transition in Epilepsies held in Paris in June 2016. This paper addresses the outcome for some particularly challenging childhood-onset epileptic disorders with the goal of recommending the best approach to transition. We have grouped these disorders in five categories with a few examples for each. The first group includes disorders presenting in childhood that may have late- or adult-onset epilepsy (metabolic and mitochondrial disorders). The second group includes disorders with changing problems in adulthood (tuberous sclerosis complex, Rett syndrome, Dravet syndrome, and autism). A third group includes epilepsies that change with age (Childhood Absence Epilepsy, Juvenile Myoclonic Epilepsy, West Syndrome, and Lennox-Gastaut syndrome). A fourth group consists of epilepsies that vary in symptoms and severity depending on the age of onset (autoimmune encephalitis, Rasmussen's syndrome). A fifth group has epilepsy from structural causes that are less likely to evolve in adulthood. Finally we have included a discussion about the risk of later adulthood cerebrovascular disease and dementia following childhood-onset epilepsy. A detailed knowledge of each of these disorders should assist the process of transition to be certain that attention is paid to the most important age-related symptoms and concerns.

The economic burden of tuberous sclerosis complex in the UK: A retrospective cohort study in the Clinical Practice Research Datalink

BACKGROUND

Tuberous sclerosis complex (TSC) is a multi-system genetic disorder characterized by the development of diverse clinical manifestations. The complexity of this disease is likely to result in substantial challenges and costs in disease management throughout the patient's lifetime. This retrospective database study aims to quantify healthcare resources utilized by TSC patients.

METHODS

TSC patients in the Clinical Practice Research Datalink linked to the Hospital Episodes Statistics database were identified between January 1987 and June 2013. Analyses were conducted over the most recent 3-year period of data and stratified by pediatric (< 18) and adult patients. Prescriptions, procedures, diagnostic tests, and healthcare encounters were reported in comparison with a matched comparator cohort. Costs and key economic drivers by primary organ system manifestations were also examined.

RESULTS

A total of 286 patients with TSC were identified and consistently reported 2-fold greater resource use than the matched presumably healthy controls. Despite this comparatively greater resource use, half of TSC patients did not record any procedures, and 20% of patients did not record any diagnostic tests; however, inpatient hospitalizations were greater for the TSC cohort (3.1 vs 1.3), but length of stay was comparable. TSC patients had costs totaling £12,681 per patient over the 3-year period, a figure 2.7-fold greater than the total costs in the comparator cohort (£4,777). Costs for patients with specific primary manifestations were even greater, with brain manifestations incurring £22,139 per affected patient. Kidney and nervous system manifestations were the main cost drivers.

CONCLUSIONS

The economic burden of TSC and its impact on NHS healthcare resources is mostly attributable to the broad spectrum of manifestations that develop within multiple organ systems. TSC patients may benefit from co-ordinated care based on their requirement for high numbers of healthcare visits across specialties.

Roles of mTOR complexes in the kidney: implications for renal disease and transplantation

The mTOR pathway has a central role in the regulation of cell metabolism, growth and proliferation. Studies involving selective gene targeting of mTOR complexes (mTORC1 and mTORC2) in renal cell populations and/or pharmacologic mTOR inhibition have revealed important roles of mTOR in podocyte homeostasis and tubular transport. Important advances have also been made in understanding the role of mTOR in renal injury, polycystic kidney disease and glomerular diseases, including diabetic nephropathy. Novel insights into the roles of mTORC1 and mTORC2 in the regulation of immune cell homeostasis and function are helping to improve understanding of the complex effects of mTOR targeting on immune responses, including those that impact both de novo renal disease and renal allograft outcomes. Extensive experience in clinical renal transplantation has resulted in successful conversion of patients from calcineurin inhibitors to mTOR inhibitors at various times post-transplantation, with excellent long-term graft function. Widespread use of this practice has, however, been limited owing to mTOR-inhibitor- related toxicities. Unique attributes of mTOR inhibitors include reduced rates of squamous cell carcinoma and cytomegalovirus infection compared to other regimens. As understanding of the mechanisms by which mTORC1 and mTORC2 drive the pathogenesis of renal disease progresses, clinical studies of mTOR pathway targeting will enable testing of evolving hypotheses.

Tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects multiple organ systems and is caused by loss-of-function mutations in one of two genes: TSC1 or TSC2. The disorder can affect both adults and children. First described in depth by Bourneville in 1880, it is now estimated that nearly 2 million people are affected by the disease worldwide. The clinical features of TSC are distinctive and can vary widely between individuals, even within one family. Major features of the disease include tumours of the brain, skin, heart, lungs and kidneys, seizures and TSC-associated neuropsychiatric disorders, which can include autism spectrum disorder and cognitive disability. TSC1 (also known as hamartin) and TSC2 (also known as tuberin) form the TSC protein complex that acts as an inhibitor of the mechanistic target of rapamycin (mTOR) signalling pathway, which in turn plays a pivotal part in regulating cell growth, proliferation, autophagy and protein and lipid synthesis. Remarkable progress in basic and translational research, in addition to several randomized controlled trials worldwide, has led to regulatory approval of the use of mTOR inhibitors for the treatment of renal angiomyolipomas, brain subependymal giant cell astrocytomas and pulmonary lymphangioleiomyomatosis, but further research is needed to establish full indications of therapeutic treatment. In this Primer, we review the state-of-the-art knowledge in the TSC field, including the molecular and cellular basis of the disease, medical management, major knowledge gaps and ongoing research towards a cure.

An estimation of the incidence of tuberous sclerosis complex in a nationwide retrospective cohort study (1997-2010)

BACKGROUND

Tuberous sclerosis complex (TSC) is caused by mutations in TSC1 and TSC2, leading to mammalian target of rapamycin hyperactivation. Patients with TSC develop hamartomas in brain, lungs, liver and skin. Two epidemiological studies, performed in Minnesota, U.S.A., have estimated the incidence of TSC to be 0·28-0·56 per 100 000 person-years (PY), based on < 12 patients. Furthermore, whether common comorbidities are associated with this rare disease is not known.

OBJECTIVES

To estimate the incidence of TSC and investigate the associations of TSC with other comorbidities, including diabetes, peptic ulcers, stroke and myocardial infarction.

METHODS

We estimated the incidence and prevalence of TSC and its comorbidities from 1997 to 2010, based on the Catastrophic Illness Certificate disease database and a beneficiary cohort of 1 million people.

RESULTS

The incidence of TSC in Taiwan is 0·153 per 100 000 PY. The number of patients identified with TSC in Taiwan doubled from 206 in 2006 to 471 in 2010. In 2010, the prevalence of TSC in Taiwan was estimated to be 1·58 in 100 000. We confirmed that female patients with TSC are more likely to develop renal tumours than male patients. Surprisingly, patients with TSC have a significantly decreased risk of developing peptic ulcers compared with controls.

CONCLUSIONS

This is the first large-scale and longitudinal incidence study of TSC. This study provides compelling evidence that TSC mutations in humans are associated with a decreased risk of peptic ulcers.

Tuberous Sclerosis Australia: a case study of a maturing patient-driven organisation

Purpose

– Tuberous Sclerosis Australia (TSA) is a small rare disease organisation with a large scope. TSA was established in 1981 as a peer support organisation. Since then, its role has evolved to meet the needs of its members: individuals living with tuberous sclerosis complex (TSC), their families and health professionals. The paper aims to discuss these issues.

Design/methodology/approach

– This case study describes the diverse activities of TSA which include, but are not limited to: the provision of information and support services; sponsorship of research and fostering a network of TSC health professionals. The benefits of collaborations forged under the umbrella organisation TSC International are highlighted.

Findings

– The case study demonstrates some of the key challenges TSA faces, challenges shared by many similar health charities. These include: funding of health education and promotion activities; working with a large range of health professionals and the challenge of research fatigue.

Originality/value

– There is little research published describing the work of small disease specific organisations similar to TSA. This case study provides insight for those collaborating with similar organisations including health professionals and researchers.