Tuberous sclerosis complex: clinical features, diagnosis, and prevalence within Northern Ireland

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.

Early patterns of functional brain development associated with autism spectrum disorder in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a rare genetic disorder that confers a high risk for autism spectrum disorders (ASD), with behavioral predictors of ASD emerging early in life. Deviations in structural and functional neural connectivity are highly implicated in both TSC and ASD. For the first time, we explore whether electroencephalographic (EEG) measures of neural network function precede or predict the emergence of ASD in TSC. We determine whether altered brain function (a) is present in infancy in TSC, (b) differentiates infants with TSC based on ASD diagnostic status, and (c) is associated with later cognitive function. We studied 35 infants with TSC (N = 35), and a group of typically developing infants (N = 20) at 12 and 24 months of age. Infants with TSC were later subdivided into ASD and non-ASD groups based on clinical evaluation. We measured features of spontaneous alpha oscillations (6-12 Hz) that are closely associated with neural network development: alpha power, alpha phase coherence (APC), and peak alpha frequency (PAF). Infants with TSC demonstrated reduced interhemispheric APC compared to controls at 12 months of age, and these differences were found to be most pronounced at 24 months in the infants who later developed ASD. Across all infants, PAF at 24 months was associated with verbal and nonverbal cognition at 36 months. Associations between early network function and later neurodevelopmental and cognitive outcomes highlight the potential utility of early scalable EEG markers to identify infants with TSC requiring additional targeted intervention initiated very early in life. Autism Res 2019, 12: 1758-1773. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Approximately half of infants with tuberous sclerosis complex (TSC) develop autism. Here, using EEG, we find that there is a reduction in communication between brain regions during infancy in TSC, and that the infants who show the largest reductions are those who later develop autism. Being able to identify infants who show early signs of disrupted brain development may improve the timing of early prediction and interventions in TSC, and also help us to understand how early brain changes lead to autism.

Epilepsy, impaired functioning, and quality of life in patients with tuberous sclerosis complex

OBJECTIVE

To estimate health-related quality of life (HRQoL) in patients with tuberous sclerosis complex (TSC) and associated manifestations and to identify potential factors associated with HRQoL in this population of patients.

METHODS

We performed a retrospective chart review of adults with TSC who attended the outpatient clinic of the University Medical Center Utrecht in the Netherlands from 1990 to 2015 (N = 363; on average 33.6 years of follow-up). HRQoL data were assessed in 2012 using the Health Utility Index version 3 (HUI-3) questionnaire completed by patients or caregivers (N = 214 with HUI score and ≥1 TSC manifestation, including renal angiomyolipomas [rAMLs], subependymal giant cell astrocytoma [SEGA], or epilepsy).

RESULTS

Of 214 patients in the study sample, 171 had TSC-associated epilepsy (with or without rAML/SEGA), 37 had TSC and rAML (without epilepsy or SEGA), and 6 had other combinations of manifestations. The median HUI score for the 214 patients with ≥1 TSC manifestation was 0.51 (-0.371 to 1 scale, 1 = perfect health, 0 = death, <0 = worse than death). Among all components used to build the overall HUI score, the cognition component had the lowest score (mean = 0.47; 0-1 scale). Patients with TSC-epilepsy had significantly lower overall HUI than patients with TSC and rAML only (median HUI = 0.31 vs 0.95, P < .05), especially those who were in refractory state for prolonged periods of time (median HUI = -0.11 among patients with seizures during the entire duration of their follow-up time). In multivariate analyses, severe impairment of daily functioning was the strongest predictor of HRQoL decrement (adjusted HUI difference between patients with severe vs. no impairment = -0.55, P < .05).

SIGNIFICANCE

This study showed that TSC-related epilepsy is associated with lower HUI, especially for patients who have refractory seizures for prolonged periods of time. Early and effective interventions to control or reduce seizures and preserve patients' cognitive functions may help to improve patients' quality of life.

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.