Sleep disorders in rare genetic syndromes: a meta-analysis of prevalence and profile

Lower respiratory rate during sleep in children with angelman syndrome compared to age-matched controls

BACKGROUND

Angelman syndrome (AS) is a rare genetic neurodevelopmental disorder caused by the absence of a functional UBE3A gene, leading to developmental, behavioral, and medical challenges. Sleep disturbances, including sleep-disordered breathing, are common in AS. This study, for the first time, investigates nocturnal respiration in individuals with AS and healthy controls at home in a long term setting.

METHODS

A non-invasive ballistocardiography-based (BCG) sleep monitoring device ("sleep mat") placed under the participants' mattresses, was used to remotely monitor children with AS aged 1 to 12 years (6.0 ± 3.2 years, n = 40) and age-matched typically developing controls (TDC) (6.2 ± 3.5 years, n = 20) for approximately 12 months. The sleep mat recorded physiological signals during times in bed. We applied fast-Fourier transformation (FFT) to exclude segments without a clear respiratory signal, thereby minimizing the impact of large body movements, wakefulness, or seizure activity. Moreover, polysomnography (PSG) was collected for up to three nights for each participant in their home. Clinical characteristics, genotype, and Bayley Scales of Infant and Toddler Development® (Bayley-III) were also analyzed.

RESULTS

The average median BCG-derived respiratory rate over the entire study duration was significantly lower in AS compared to TDCs (Cohen's d = 1.31). PSG-derived respiration data corroborated the lower breathing rate in AS (Cohen's d = 0.77) and revealed a strong correlation between BCG and PSG derived respiration (r = 0.85) and thus a strong convergent validity of the sleep mat against "gold standard" measures. Next, we defined two groups of AS individuals based on their respiratory rates: a normal respiration group with rates above the minimum in TDC, and a low respiratory rate group with rates below the TDC group's minimum. A higher prevalence of respiratory abnormalities was observed in deletion carriers (55.2%) versus non-deletion carriers (9.1%). Pulse oximetry data indicated lower oxygen saturation levels in AS individuals (Cohen's d = 1.60). Moreover, lower Bayley-III scores were observed in the low respiration group, suggesting a link between respiratory dysfunction and neurodevelopmental outcomes in AS. Medication use, particularly antiepileptic drugs, was found to suppress respiratory rates, highlighting the complex interplay between concomitant medication use, genotype, and sleep in AS.

CONCLUSION

Our study provides the first long-term observational evidence of a persistent bradypnea-like phenotype in individuals with AS, which may have significant implications for their clinical management. The successful use of the sleep mat device as a non-invasive physiological ambulatory monitoring tool demonstrates its potential as a digital health technology for detecting respiratory abnormalities in pediatric neurodevelopmental disorders. These findings should be further assessed and may have biomarker and clinical utility in AS, particularly in relation to seizure management and cognitive development.

The interplay between genomic copy number variants, sleep, and cognition in the general population

Genomic Copy Number variants (CNVs) increase risk for neurodevelopmental disorders (NDDs) and affect cognition, but their impact on sleep remains understudied despite the well-established link between sleep disturbances, NDDs, and cognition. We investigated the relationship between CNVs, sleep traits, cognitive ability, and executive function in 498,852 individuals from an unselected population in the UK Biobank. We replicated the U-shape relationship between measures of cognitive ability and sleep duration. The effects of CNVs on sleep duration were evident at the genome-wide level; CNV-burden analyses showed that overall, CNVs with an increasing number of intolerant genes were associated with increased or decreased sleep duration in a U-shape pattern (p < 2e-16), but did not increase risk of insomnia. Sleep duration only marginally mediated the robust association between CNVs and poorer cognitive performance, suggesting that sleep and cognitive phenotypes may result from pleiotropic effects of CNVs with minimal causal relationship.

The Lighter Touch: Less-Restriction in Sequentially Implemented Behavioral Sleep Interventions for Children with Rare Genetic Neurodevelopmental Conditions

PURPOSE

The prevalence of sleep difficulties among children with rare genetic neurodevelopmental conditions (RGNC) is high. Behavioral interventions are commonly used in the treatment of sleep difficulties in children with neurodevelopmental conditions such as autism, however, research is scarce in children with RGNC. The range of co-occurring complexities within this population, means there is a need for research to not only determine the effectiveness of behavioral sleep interventions, but also which components might be the least restrictive (i.e., intensive/aversive) and minimally sufficient.

METHODS

This study used a single-case multiple baseline design to investigate the effectiveness and acceptability of behavioral sleep interventions, indicated within a Functional Behavior formulation in eight children with RGNC (M = 7.3 years). Intervention components were sequentially administered across up to three phases, based on the principle of less restriction (from least to relatively more intensive) to determine what might be minimally sufficient.

RESULTS

Results showed an improvement in sleep onset latency, night wakings, early morning waking and unwanted bed-sharing for 7/7, 6/7, 3/3 and 3/3 children respectively. Improvement was observed for most participants following the less restrictive phases of intervention (circadian modifications, antecedent modifications and positive reinforcement), however, more restrictive, albeit modified, extinction procedures were still implemented for five participants. Improvements were maintained at follow-up and interventions were deemed acceptable to parents.

CONCLUSIONS

Less restrictive function-based behavioral strategies are an effective, and in some cases sufficient, contribution to a sequence of interventions for a range of sleep difficulties. They should be implemented first, before more restrictive strategies.

Sleep and circadian disturbances in children with neurodevelopmental disorders

Sleep is essential for brain development and overall health, particularly in children with neurodevelopmental disorders (NDDs). Sleep disruptions can considerably impact brain structure and function, leading to dysfunction of neurotransmitter systems, metabolism, hormonal balance and inflammatory processes, potentially contributing to the pathophysiology of NDDs. This Review examines the prevalence, types and mechanisms of sleep disturbances in children with NDDs, including autism spectrum disorder, attention-deficit hyperactivity disorder and various genetic syndromes. Common sleep disorders in these populations include insomnia, hypersomnia, circadian rhythm disorders, sleep-related breathing disorders and parasomnias, with underlying factors often involving genetic, neurobiological, environmental and neurophysiological influences. Sleep problems such as insomnia, night awakenings and sleep fragmentation are closely linked to both internalizing symptoms such as anxiety and depression, and externalizing behaviours such as hyperactivity and aggression. Assessment of sleep in children with NDDs presents unique challenges owing to communication difficulties, comorbid conditions and altered sensory processing. The Review underscores the importance of further research to unravel the complex interactions between sleep and neurodevelopment, advocating for longitudinal studies and the identification of predictive biomarkers. Understanding and addressing sleep disturbances in NDDs is crucial for improving developmental outcomes and the overall quality of life for affected individuals and their families.

Sleep Problems in Children With Developmental Delays and Neurodevelopmental Comorbidities: A Retrospective Cross-Sectional Study

Background Sleep disturbances are more common in children with developmental delay (DD) than in typically developing children. There is limited research on whether sleep impact is more pronounced in children with DD and comorbidities. Objective Our study compared sleep patterns and disturbances in children with DD and neurological or psychobehavioral comorbidities to those with isolated DD. Methodology We conducted a single-center retrospective study utilizing a parent-rated questionnaire on neurodevelopmental clinic attendees over six months. Subjects were categorized into three groups: (1) isolated DD; (2) DD with comorbid neurological conditions; and (3) DD with comorbid psychobehavioral conditions. Results A total of 529 subjects were included. The results revealed minimal differences in sleep schedules between the groups. More than half of the sample (276, 52.2%) had insufficient sleep hours, with no significant variation across groups. A substantial proportion of the sample took regular naps, with 340 (79.3%) on weekdays and 279 (69.9%) on weekends. Compared to the isolated DD group, the comorbid neurological group showed a higher sleep resistance score, while comorbid psychobehavioral conditions were associated with higher sleep resistance scores and lower sleep parasomnia scores. A lower portion of the comorbid neurological group had their parents satisfied with their sleep quality (16, 32.7%, vs. 121, 52.2%). A higher percentage of parents in the comorbid psychobehavioral group reported significant daily life impact due to their children's sleep problems (65, 28.0%, vs. 41, 17.1%). Conclusions The sleep schedule in all three groups closely resembled each other. All three groups exhibited a high prevalence of sleep-related problems. Regular screening for sleep problems is recommended, particularly for children with DD and neurological or psychobehavioral comorbidities.

Use of Basket Trials to Solve Sleep Problems in Patients with Rare Diseases

The need for sleep is universal, and the ability to meet this need impacts the quality of life for patients, families, and caregivers. Although substantial progress has been made in treating rare diseases, many patients have unmet medical sleep needs, and current regulatory policy makes it prohibitively difficult to address those needs medically. This opinion reviews the rare disease experience with sleep disorders and explores potential solutions. First, we provide case profiles for the rare diseases Wilson's Disease, Angelman Syndrome, and Prader-Willi Syndrome. These profiles highlight challenges in rare disease diagnosis and barriers to pinpointing disease pathophysiology, including biomarkers that intersect with sleep disorders. Second, we transition to a bird's eye view of sleep disorders and rare diseases by reporting input from a stakeholder discussion with the U.S. Food and Drug Administration regarding abnormal sleep patterns in various rare diseases. Last, in response to the profound unmet medical needs of patients with rare diseases and sleep disorders, we propose adapting and using the clinical trial design known as a "basket trial". In this case, a basket trial would include patients with different rare diseases but the same debilitating symptoms. This research approach has the potential to benefit many rare disease patients who are otherwise left with profound unmet medical needs.

Sleep Abnormalities in SLC13A5 Citrate Transporter Disorder

BACKGROUND

SLC13A5 Citrate Transporter Disorder is a rare pediatric neurodevelopmental disorder. Patients have epilepsy, developmental disability, and impaired mobility. While sleep disorders are common in children with neurodevelopmental disorders, sleep abnormalities have not been reported in SLC13A5 patients.

METHODS

Here, we assessed sleep disturbances in patients through caregiver reported surveys and in a transgenic mouse model of SLC13A5 deficiency. A total of 26 patients were evaluated with the Sleep Disturbance Scale for Children three times over a one-year span. Sleep and wake activities were assessed in the SLC13A5 knock-out (KO) mice using wireless telemetry devices.

RESULTS

A high burden of clinically significant sleep disturbances were reported in the patients, with heterogeneous symptoms that remained stable across time. While sleep disturbances were common, less than 30% of patients were prescribed medications for sleep. Comparatively, in SLC13A5 KO mice using EEG recordings, significant alterations were found during light cycles, when rodents typically sleep. During the sleep period, SLC13A5 mice had increased activity, decreased paradoxical sleep, and changes in absolute power spectral density, indicating altered sleep architecture in the mouse model.

CONCLUSIONS

Our results demonstrate a significant component of sleep disturbances in SLC13A5 patients and mice, highlighting a potential gap in patient care. Further investigation of sleep dysfunction and the underlying etiologies of sleep disturbances in SLC13A5 citrate transporter disorder is warranted.

Sleep-disordered breathing in children and adults with intellectual disability: mind the gap!

BACKGROUND

In adults and children with intellectual disability (ID), sleep -disordered breathing (SDB) is thought to be common. However, large epidemiological studies are lacking, and there are few studies on optimal methods of investigation and even fewer randomised, controlled intervention trials of treatment.

METHOD

Peer-reviewed publications from various databases were examined in line with search terms relevant to ID and SDB spanning the years 200-2024.

RESULTS

Findings suggest that, due to comorbid conditions, children and adults with ID may experience both an increased risk of SDB, as well as lower frequency of diagnosis. SDB can compromise the emotional, physical and mental health of individuals with ID. Appropriate treatment when tolerated leads to an improvement in health and well-being and several studies emphasized the importance of consistent follow-up of people with ID - something that is not universally occurring during childhood, in the transition to adulthood and during adulthood itself. As the most frequently occurring form of ID worldwide, we use Down syndrome as a specific example of how diagnosing and treating SDB can lead to improved outcomes.

CONCLUSIONS

This review highlights the importance of identifying SDB in this heterogenous population, recognising the multi-faceted, deleterious consequences of untreated SDB in people with ID, and presents some strategies that can be harnessed to improve diagnosis and management. Until further ID-specific research is available, we urge flexibility in the approach to people with ID and SDB based in guidelines and standard practice developed for the typically developing population.

Circadian Rhythm and Sleep Analyses in a Fruit Fly Model of Fragile X Syndrome Using a Video-Based Automated Behavioral Research System

Fragile X syndrome (FXS) is caused by the full mutation in the FMR1 gene on the Xq27.3 chromosome region. It is the most common monogenic cause of autism spectrum disorder (ASD) and inherited intellectual disability (ID). Besides ASD and ID and other symptoms, individuals with FXS may exhibit sleep problems and impairment of circadian rhythm (CR). The Drosophila melanogaster models of FXS, such as dFMR1B55, represent excellent models for research in the FXS field. During this study, sleep patterns and CR in dFMR1B55 mutants were analyzed, using a new platform based on continuous high-resolution videography integrated with a highly-customized version of an open-source software. This methodology provides more sensitive results, which could be crucial for all further research in this model of fruit flies. The study revealed that dFMR1B55 male mutants sleep more and can be considered weak rhythmic flies rather than totally arrhythmic and present a good alternative animal model of genetic disorder, which includes impairment of CR and sleep behavior. The combination of affordable videography and software used in the current study is a significant improvement over previous methods and will enable broader adaptation of such high-resolution behavior monitoring methods.

Adult Inception of Ketogenic Diet Therapy Increases Sleep during the Dark Cycle in C57BL/6J Wild Type and Fragile X Mice

Sleep problems are a significant phenotype in children with fragile X syndrome. Our prior work assessed sleep-wake cycles in Fmr1KO male mice and wild type (WT) littermate controls in response to ketogenic diet therapy where mice were treated from weaning (postnatal day 18) through study completion (5-6 months of age). A potentially confounding issue with commencing treatment during an active period of growth is the significant reduction in weight gain in response to the ketogenic diet. The aim here was to employ sleep electroencephalography (EEG) to assess sleep-wake cycles in mice in response to the Fmr1 genotype and a ketogenic diet, with treatment starting at postnatal day 95. EEG results were compared with prior sleep outcomes to determine if the later intervention was efficacious, as well as with published rest-activity patterns to determine if actigraphy is a viable surrogate for sleep EEG. The data replicated findings that Fmr1KO mice exhibit sleep-wake patterns similar to wild type littermates during the dark cycle when maintained on a control purified-ingredient diet but revealed a genotype-specific difference during hours 4-6 of the light cycle of the increased wake (decreased sleep and NREM) state in Fmr1KO mice. Treatment with a high-fat, low-carbohydrate ketogenic diet increased the percentage of NREM sleep in both wild type and Fmr1KO mice during the dark cycle. Differences in sleep microstructure (length of wake bouts) supported the altered sleep states in response to ketogenic diet. Commencing ketogenic diet treatment in adulthood resulted in a 15% (WT) and 8.6% (Fmr1KO) decrease in body weight after 28 days of treatment, but not the severe reduction in body weight associated with starting treatment at weaning. We conclude that the lack of evidence for improved sleep during the light cycle (mouse sleep time) in Fmr1KO mice in response to ketogenic diet therapy in two studies suggests that ketogenic diet may not be beneficial in treating sleep problems associated with fragile X and that actigraphy is not a reliable surrogate for sleep EEG in mice.

The Type, Severity, and Impact of Sleep Problems in Children With Angelman Syndrome and Parental Help-seeking Patterns

Angelman syndrome (AS) is a rare genetic developmental disability that presents with high rates of co-occurring sleep difficulties. Most existing research has focused on the pathophysiology of sleep problems in people with AS, and suggests that sleep problems are the result of genetic and neurobiological factors. However, little is known about the role of the social environment and learning in sleep problems in children with AS. This descriptive study used survey data from 139 parents of children with AS to investigate: 1) the type, topography and severity of children's sleep problems; 2) the collateral child, parent and family impacts of the sleep problems; 3) treatment selection practices and the perceived effectiveness of these treatments; and 4) sources of support and treatment advice received. Parents reported that the majority of children experienced sleep problems, resulting in numerous deleterious effects on child and family functioning. They also reported high levels of concern about these sleep problems, but low levels of perceived support. Study findings highlight the need to establish a disability-specific profile of the type and impact of sleep problems experienced by children with AS, and have further implications for the delivery of clinical services and support provided to parents of children with AS.

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

BACKGROUND

Overactivity is prevalent in several rare genetic neurodevelopmental syndromes, including Smith-Magenis syndrome, Angelman syndrome, and tuberous sclerosis complex, although has been predominantly assessed using questionnaire techniques. Threats to the precision and validity of questionnaire data may undermine existing insights into this behaviour. Previous research indicates objective measures, namely actigraphy, can effectively differentiate non-overactive children from those with attention-deficit hyperactivity disorder. This study is the first to examine the sensitivity of actigraphy to overactivity across rare genetic syndromes associated with intellectual disability, through comparisons with typically-developing peers and questionnaire overactivity estimates.

METHODS

A secondary analysis of actigraphy data and overactivity estimates from The Activity Questionnaire (TAQ) was conducted for children aged 4-15 years with Smith-Magenis syndrome (N=20), Angelman syndrome (N=26), tuberous sclerosis complex (N=16), and typically-developing children (N=61). Actigraphy data were summarized using the M10 non-parametric circadian rhythm variable, and 24-hour activity profiles were modelled via functional linear modelling. Associations between actigraphy data and TAQ overactivity estimates were explored. Differences in actigraphy-defined activity were also examined between syndrome and typically-developing groups, and between children with high and low TAQ overactivity scores within syndromes.

RESULTS

M10 and TAQ overactivity scores were strongly positively correlated for children with Angelman syndrome and Smith-Magenis syndrome. M10 did not substantially differ between the syndrome and typically-developing groups. Higher early morning activity and lower evening activity was observed across all syndrome groups relative to typically-developing peers. High and low TAQ group comparisons revealed syndrome-specific profiles of overactivity, persisting throughout the day in Angelman syndrome, occurring during the early morning and early afternoon in Smith-Magenis syndrome, and manifesting briefly in the evening in tuberous sclerosis complex.

DISCUSSION

These findings provide some support for the sensitivity of actigraphy to overactivity in children with rare genetic syndromes, and offer syndrome-specific temporal descriptions of overactivity. The findings advance existing descriptions of overactivity, provided by questionnaire techniques, in children with rare genetic syndromes and have implications for the measurement of overactivity. Future studies should examine the impact of syndrome-related characteristics on actigraphy-defined activity and overactivity estimates from actigraphy and questionnaire techniques.

Association between transition patterns of sleep problems and suicidal ideation in Chinese female nurses: A prospective study

OBJECTIVE

Suicidal ideation and sleep problems are both common in nurses. However, few longitudinal studies are available to examine the temporal association between sleep and suicidal ideation in nurses.

METHOD

Data from the Health Longitudinal Survey of Nurses in Shandong Province was analyzed, involving 623 female nurses who had completed data of concern in 2018 (T1) and 2019 (T2). Sleep problem was assessed by the Pittsburgh Sleep Quality Index, in which the transition patterns for global and specific sleep component and the cumulative number of sleep component problems were defined. Suicidal ideation was measured by the ninth item of the Patient Health Questionnaire. Binary logistic regression was used to explore the association between sleep and suicidal ideation.

RESULTS

Chronic and deteriorated global sleep problems is associated with a greater risk of suicidal ideation. For the specific component of sleep, sleep disturbance and short sleep duration are associated with a higher risk of suicidal ideation. The higher number of cumulative sleep component problems is associated with a higher risk of suicidal ideation.

CONCLUSION

Findings indicate sleep disturbance and short sleep duration may be pathways to suicidal ideation. Initiatives that target at sleep problems may be important to reduce suicidal ideation in nurses.

Sleep in people with and without intellectual disabilities: a systematic review and meta-analysis

BACKGROUND

Sleep problems are regularly reported in people with intellectual disabilities. Recent years have seen a substantial increase in studies comparing sleep in people with intellectual disabilities to control participants, with an increase in the use of validated, objective measures. Emerging patterns of differences in sleep time and sleep quality warrant pooled investigation.

METHODS

A systematic search was conducted across three databases (Ovid Embase, PsycInfo and Medline) and returned all papers comparing sleep in people with intellectual disabilities to a control group, published since the last meta-analysis on the topic. A quality framework was employed to rate the risk of bias across studies. Separate meta-analyses of sleep duration and sleep quality were conducted. Subgrouping compared findings for those studies with participants with genetic syndromes or neurodevelopmental conditions and those with heterogeneous intellectual disability.

RESULTS

Thirteen new papers were identified and combined with those from the previous meta-analysis to provide 34 papers in total. Quality of studies was generally rated highly, though sampling provided risk of bias and adaptive functioning was rarely measured. People with intellectual disability associated with genetic syndromes or neurodevelopmental conditions sleep for shorter time periods (standardised mean difference = .26) and experience worse sleep quality (standardised mean difference = .68) than their peers. People with intellectual disability of heterogeneous origin show no difference in sleep time but have poorer sleep quality. There was some evidence that age moderated these effects.

CONCLUSIONS

People with intellectual disability have poorer sleep than those without. Subtle patterns suggest that aetiology of intellectual disability moderates the topography of these difficulties, with further work needed to differentiate common and distinct mechanisms across groups.

Sleep and Circadian Disturbances in Children With Neurodevelopmental Disorders

Sleep problems are highly prevalent in those with neurodevelopmental disorders (NDDs). We propose this is secondary to multiple factors that directly and indirectly negatively impact sleep and circadian processes in those with NDDs, which in turn, further perturbs development, resulting in a "developmental and sleep/circadian-related encephalopathy." In this review, we discuss select NDDs with known or suspected sleep and circadian phenotypes. We also highlight important considerations when evaluating and treating sleep and circadian disorders in these populations.

X-Chromosome Dependent Differences in the Neuronal Molecular Signatures and Their Implications in Sleep Patterns

Biological factors and mechanisms that drive sex differences observed in sleep disturbances are understudied and poorly understood. The extent to which sex chromosome constitution impacts on sex differences in circadian patterns is still a knowledge void in the sleep medicine field. Here we focus on the neurological consequences of X-chromosome functional imbalances between males and females and how this molecular inequality might affect sex divergencies on sleep. In light of the X-chromosome inactivation mechanism in females and its implications in gene regulation, we describe sleep-related neuronal circuits and brain regions impacted by sex-biased modulations of the transcriptome and the epigenome. Benefited from recent large-scale genetic studies on the interplay between X-chromosome and brain function, we list clinically relevant genes that might play a role in sex differences in neuronal pathways. Those molecular signatures are put into the context of sleep and sleep-associated neurological phenotypes, aiming to identify biological mechanisms that link X-chromosome gene regulation to sex-biased human traits. These findings are a significant step forward in understanding how X-linked genes manifest in sleep-associated transcriptional networks and point to future research opportunities to address female-specific clinical manifestations and therapeutic responses.

Concordance of objective and subjective measures of sleep in children with neurodevelopmental conditions: A systematic review and meta-analysis

The purpose of this systematic review and meta-analysis is to delineate the concordance of objective and subjective measures of sleep in children with neurodevelopmental conditions (NDCs). A systematic literature search identified 31 studies that compare objective and subjective estimates of sleep parameters in autism, ADHD or rare genetic syndromes associated with intellectual disability. The meta-analyses revealed smaller mean differences and larger correlations indicative of greater concordance for parameters associated with sleep scheduling compared to parameters associated with sleep duration and night awakenings. Relative to objective measures, subjective measures produced: 1) greater estimates of total sleep time, sleep efficiency and time in bed; and 2) lower estimates of wake after sleep onset and number of night awakenings. Subgroup analyses also revealed differences in concordance between measurement comparison types (e.g., stronger correlations between actigraphy and sleep diaries, compared to actigraphy and questionnaires) and NDC diagnostic groups. The results predominantly replicate concordance trends observed in typically-developing samples, although some NDC-specific patterns of concordance were identified. This indicates that objective and subjective sleep measures retain broadly similar properties across populations, although researchers and clinicians should be cautious of the impact of NDC-related characteristics on sleep parameter estimates. These findings should inform sleep assessment design and the interpretation of sleep parameter estimates in NDCs, increasing the rigour of sleep parameter description across research and clinical settings.

Ketogenic Diet Affects Sleep Architecture in C57BL/6J Wild Type and Fragile X Mice

Nearly half of children with fragile X syndrome experience sleep problems including trouble falling asleep and frequent nighttime awakenings. The goals here were to assess sleep-wake cycles in mice in response to Fmr1 genotype and a dietary intervention that reduces hyperactivity. Electroencephalography (EEG) results were compared with published rest-activity patterns to determine if actigraphy is a viable surrogate for sleep EEG. Specifically, sleep-wake patterns in adult wild type and Fmr1KO littermate mice were recorded after EEG electrode implantation and the recordings manually scored for vigilance states. The data indicated that Fmr1KO mice exhibited sleep-wake patterns similar to wild type littermates when maintained on a control purified ingredient diet. Treatment with a high-fat, low-carbohydrate ketogenic diet increased the percentage of non-rapid eye movement (NREM) sleep in both wild type and Fmr1KO mice during the dark cycle, which corresponded to decreased activity levels. Treatment with a ketogenic diet flattened diurnal sleep periodicity in both wild type and Fmr1KO mice. Differences in several sleep microstructure outcomes (number and length of sleep and wake bouts) supported the altered sleep states in response to a ketogenic diet and were correlated with altered rest-activity cycles. While actigraphy may be a less expensive, reduced labor surrogate for sleep EEG during the dark cycle, daytime resting in mice did not correlate with EEG sleep states.

Behavioural sleep problems in children and adults with intellectual disabilities: An integrative literature review

BACKGROUND

People with intellectual disabilities are more likely to experience sleep problems, which can affect quality of life, physical health, mental health and well-being.

METHODS

An integrative literature review was conducted to investigate what is known about behavioural sleep disturbances in people with an intellectual disability. The search used the following databases: Scopus, PsycInfo and Cinahl, to find papers published since 2015.

RESULTS

Within intellectual disability research, sleep appears as a common issue due to its high prevalence, negative relationships with an individual's physical and mental health, their quality of life, and impact of sleep problems on family or carers. The growing evidence base appears to support the use of behavioural, lifestyle and pharmacological interventions to improve sleep in people with an intellectual disability.

CONCLUSION

A wide array of literature provides evidence that people with intellectual disabilities are affected by and need support with their sleep.

Behavioural and physiological indicators of anxiety reflect shared and distinct profiles across individuals with neurogenetic syndromes

Anxiety is heightened in individuals with intellectual disability, particularly in those with specific neurogenetic syndromes. Assessment of anxiety for these individuals is hampered by a lack of appropriate measures that cater for communication impairment, differences in presentation, and overlapping features with co-occurring conditions. Here, we adopt a multi-method approach to identify fine-grained behavioural and physiological (via salivary cortisol) responses to anxiety presses in people with fragile X (FXS; n = 27; Mage = 20.11 years; range 6.32 - 47.04 years) and Cornelia de Lange syndromes (CdLS; n = 27; Mage = 18.42 years; range 4.28 - 41.08 years), two neurogenetic groups at high risk for anxiety, compared to neurotypical children (NT; n = 21; Mage = 5.97 years; range 4.34 - 7.30 years). Results indicate that physical avoidance of feared stimuli and proximity seeking to a familiar adult are prominent behavioural indicators of anxiety/stress in FXS and CdLS. Heightened pervasive physiological arousal was identified in these groups via salivary cortisol. An association between autistic characteristics and anxiety was evident in the FXS group but not in the CdLS group pointing to syndrome-specific nuances in the association between anxiety and autism. This study furthers understanding of the behavioural and physiological presentation of anxiety in individuals with intellectual disability and progresses theoretical developments regarding the development and maintenance of anxiety at the intersection of autism.

Pediatric Sleep Respiratory Disorders: A Narrative Review of Epidemiology and Risk Factors

Sleep is a fundamental biological necessity, the lack of which has severe repercussions on the mental and physical well-being in individuals of all ages. The phrase "sleep-disordered breathing (SDB)" indicates a wide array of conditions characterized by snoring and/or respiratory distress due to increased upper airway resistance and pharyngeal collapsibility; these range from primary snoring to obstructive sleep apnea (OSA) and occur in all age groups. In the general pediatric population, the prevalence of OSA varies between 2% and 5%, but in some particular clinical conditions, it can be much higher. While adenotonsillar hypertrophy ("classic phenotype") is the main cause of OSA in preschool age (3-5 years), obesity ("adult phenotype") is the most common cause in adolescence. There is also a "congenital-structural" phenotype that is characterized by a high prevalence of OSA, appearing from the earliest ages of life, supported by morpho-structural abnormalities or craniofacial changes and associated with genetic syndromes such as Pierre Robin syndrome, Prader-Willi, achondroplasia, and Down syndrome. Neuromuscular disorders and lysosomal storage disorders are also frequently accompanied by a high prevalence of OSA in all life ages. Early recognition and proper treatment are crucial to avoid major neuro-cognitive, cardiovascular, and metabolic morbidities.

Sleep disturbance as a transdiagnostic marker of psychiatric risk in children with neurodevelopmental risk genetic conditions

Children with rare neurodevelopmental genetic conditions (ND-GCs) are at high risk for a range of neuropsychiatric conditions. Sleep symptomatology may represent a transdiagnostic risk indicator within this patient group. Here we present data from 629 children with ND-GCs, recruited via the United Kingdom's National Health Service medical genetic clinics. Sibling controls (183) were also invited to take part. Detailed assessments were conducted to characterise the sleep phenotype of children with ND-GCs in comparison to controls. Latent class analysis was conducted to derive subgroups of children with an ND-GC based on sleep symptomatology. Assessment of cognition and psychopathology allowed investigation of whether the sleep phenotypic subgroup was associated with neuropsychiatric outcomes. We found that children with an ND-GC, when compared to control siblings, were at elevated risk of insomnia (ND-GC = 41% vs Controls = 17%, p < 0.001) and of experiencing at least one sleep symptom (ND-GC = 66% vs Controls = 39%, p < 0.001). On average, insomnia was found to have an early onset (2.8 years) in children with an ND-GC and to impact across multiple contexts. Children in subgroups linked to high sleep symptomatology were also at high risk of psychiatric outcomes (OR ranging from 2.0 to 21.5 depending on psychiatric condition). Our findings demonstrate that children with high genetic vulnerability for neurodevelopmental outcomes exhibit high rates of insomnia and sleep symptomatology. Sleep disruption has wide-ranging impacts on psychosocial function, and indexes those children at greater neuropsychiatric risk. Insomnia was found to onset in early childhood, highlighting the potential for early intervention strategies for psychiatric risk informed by sleep profile.

Association between early and current gastro-intestinal symptoms and co-morbidities in children and adolescents with Angelman syndrome

BACKGROUND

Angelman syndrome (AS) is a neurogenetic disorder that causes severe intellectual disability, expressive language deficits, motor impairment, ataxia, sleep problems, epileptic seizures and a happy disposition. People with AS frequently experience gastrointestinal (GI) symptoms.

METHOD

This study used data from the Global Angelman Syndrome Registry to explore the relationship between early and current GI symptoms and co-morbidity in children and adolescents with AS (n = 173). Two groups that experienced a high (n = 91) and a low (n = 82) frequency of GI symptoms were examined in relation to feeding and GI history in infancy, sleep and toileting problems, levels of language and communication and challenging behaviours. Predictors of GI symptoms were then investigated using a series of logistic regressions.

RESULTS

This analysis found that constipation and gastroesophageal reflux affected 84% and 64%, of the sample, respectively. The high frequency of GI symptoms were significantly associated with: 'refusal to nurse', 'vomiting', 'arching', 'difficulty gaining weight', gastroesophageal reflux, 'solid food transition', frequency of night-time urinary continence and sleep hyperhidrosis during infancy. GI symptoms were not significantly associated with sleep, toileting, language or challenging behaviours. Significant predictors of high frequency GI symptoms were gastroesophageal reflux and sleep hyperhidrosis.

CONCLUSIONS

Future research needs to investigate the association between AS and GI co-morbidity in adults with AS.

Investigating the contributions of circadian pathway and insomnia risk genes to autism and sleep disturbances

Sleep disturbance is prevalent in youth with Autism Spectrum Disorder (ASD). Researchers have posited that circadian dysfunction may contribute to sleep problems or exacerbate ASD symptomatology. However, there is limited genetic evidence of this. It is also unclear how insomnia risk genes identified through GWAS in general populations are related to ASD and common sleep problems like insomnia traits in ASD. We investigated the contribution of copy number variants (CNVs) encompassing circadian pathway genes and insomnia risk genes to ASD risk as well as sleep disturbances in children with ASD. We studied 5860 ASD probands and 2092 unaffected siblings from the Simons Simplex Collection (SSC) and MSSNG database, as well as 7509 individuals from two unselected populations (IMAGEN and Generation Scotland). Sleep duration and insomnia symptoms were parent reported for SSC probands. We identified 335 and 616 rare CNVs encompassing circadian and insomnia risk genes respectively. Deletions and duplications with circadian genes were overrepresented in ASD probands compared to siblings and unselected controls. For insomnia-risk genes, deletions (not duplications) were associated with ASD in both cohorts. Results remained significant after adjusting for cognitive ability. CNVs containing circadian pathway and insomnia risk genes showed a stronger association with ASD, compared to CNVs containing other genes. Circadian genes did not influence sleep duration or insomnia traits in ASD. Insomnia risk genes intolerant to haploinsufficiency increased risk for insomnia when duplicated. CNVs encompassing circadian and insomnia risk genes increase ASD liability with little to no observable impacts on sleep disturbances.

Sleep disturbance is a common feature of Kabuki syndrome

Kabuki syndrome (KS) is a rare epigenetic disorder caused by heterozygous loss of function variants in either KMT2D (90%) or KDM6A (10%), both involved in regulation of histone methylation. While sleep disturbance in other Mendelian disorders of the epigenetic machinery has been reported, no study has been conducted on sleep in KS. This study assessed sleep in 59 participants with KS using a validated sleep questionnaire. Participants ranged in age from 4 to 43 years old with 86% of participants having a pathogenic variant in KMT2D. In addition, data on adaptive function, behavior, anxiety, and quality of life were collected using their respective questionnaires. Some form of sleep issue was present in 71% of participants, with night-waking, daytime sleepiness, and sleep onset delay being the most prevalent. Sleep dysfunction was positively correlated with maladaptive behaviors, anxiety levels, and decreasing quality of life. Sleep issues were not correlated with adaptive function. This study establishes sleep disturbance as a common feature of KS. Quantitative sleep measures may be a useful outcome measure for clinical trials in KS. Further, clinicians caring for those with KS should consider sleep dysfunction as an important feature that impacts overall health and well being in these patients.

Sleep disturbances and behavior in Smith-Magenis syndrome

BACKGROUND

The Smith-Magenis syndrome (SMS) shows a collection of neurodevelopmental problems including mild to moderate intellectual disability, change-related anxiety, impulsivity, speech delay, Attention-Deficit/Hyperactivity Disorder (ADH) and sleep disturbances. Sleep disorders, when present, have been treated in several populations with consecutive improvements in cognitive and behavioral aspects.

AIMS

To better understand the existing relationships between sleep disturbances and behavioral problems in SMS syndrome this study describes the sleep and behavior problems in the SMS and explores the possible relation between both.

METHODS AND PROCEDURES

17 individuals with SMS (50% males; 11.2 ± 4.9 years old) and 12 individuals with typical development (50% male; 11.1 ± 4.4 years old) were investigated using the Sleep Disturbance Scale for Children and the Child Behavior Checklist.

RESULTS

A high percentage (60%) of individuals with SMS have an indication of sleep disorders, being the most frequent disorders the sleep-wake transition disorders, and disorders of initiating and maintaining sleep with sleep latency higher than acceptable and total sleep time below acceptable. More than 94% of the SMS group presented clinical or borderline scores on the total behavioral problems scale. The most common behavioral problems were Externalizing Problems, Thought and Attention, ADH and Aggressive problems. There was a positive correlation between disorders of initiating and maintaining sleep, sleep-wake transition disorders, disorders of arousal, disorders of excessive somnolence and behavioral problems.

CONCLUSIONS AND IMPLICATIONS

The worse the sleep disturbances investigated, the more severe the behavioral problems characteristics reinforcing the importance to address the sleep problems in the treatment of SMS individuals.

Direct assessment of overnight parent-child proximity in children with behavioral insomnia: Extending models of operant and classical conditioning

INTRODUCTION

Explanatory models of behavioral insomnia typically draw on operant learning theory with behavioral techniques focused on altering parent-child interactions to improve sleep. However, there are no data describing parent-child interactions overnight beyond parent report. In this study we used radio frequency identification technology to quantify parent-child proximity overnight in two groups at elevated risk of behavioral insomnia, Angelman syndrome (AS) and Smith-Magenis syndrome (SMS).

MATERIALS AND METHODS

Nineteen children aged 4-15 years (8 with AS, 11 with SMS) participated in a week-long at-home assessment of sleep and overnight parent-child proximity. Sleep parameters were recorded using the Philips Actiwatch 2 and proximity data were recorded using custom-built radio frequency identification watches.

RESULTS

Three patterns of proximity data between parent-child dyads overnight were evident: "checking" (six with AS, five with SMS), "co-sleeping" (four with SMS) and those who had "no proximity" overnight (two with AS, two with SMS). In the AS group, 25.45% of actigraphy-defined wakes resulted in a parent-child interaction. In the SMS group, 39.34% of wakes resulted in a parent-child interaction. Children who interacted with their parents when settling to sleep were not significantly more likely to interact at waking.

DISCUSSION

The novel application of radio frequency identification technology is a feasible method for studying overnight parent-child proximity. Profiles of proximity between participants that are not closely aligned with operant models of behavioral insomnia were evident. These results have significant implications for the etiology of poor sleep and the application of behavioral sleep interventions.

Diagnosis and management of sleep disorders in Prader-Willi syndrome

Clinical experience and a growing body of evidence suggest that sleep disturbances are common in people with Prader-Willi syndrome (PWS). PWS is a rare neuroendocrine disorder characterized by early hypotonia and feeding difficulties; developmental delays; endocrinopathies; and behavioral concerns, especially rigidity, anxiety, and behavioral outbursts. PWS is also characterized by decreased resting energy expenditure and transition to hyperphagia and obesity. We propose that, for many people with PWS, clinical diagnosis and management of sleep disorders is an unmet need. We present current information to suggest disordered sleep is a significant burden for individuals with PWS and often overlooked. While central and obstructive sleep apnea are more widely recognized in PWS, other sleep disorders have increasingly gained recognition, including hypersomnia, narcolepsy-like phenotypes, and insomnia. Sleep disorders can impact behavior, cognition, and quality of life and health for individuals with PWS. Our goal is to bring sleep disorders to the forefront of therapeutic intervention for patients with PWS. This paper presents a review of the literature and recommendations for clinical practice based on published research and our clinical experience as sleep specialists, geneticists, psychiatrists, pediatricians, otolaryngologists, and pulmonologists with extensive experience with this patient population. We recommend that management of sleep be considered an integral part of successful medical management of PWS. Further research concerning sleep problems in PWS is urgently needed to develop best practices and work toward a consensus statement for medical management to meet the needs of people with PWS.

CITATION

Duis J, Pullen LC, Picone M, et al. Diagnosis and management of sleep disorders in Prader-Willi syndrome. J Clin Sleep Med. 2022;18(6):1687-1696.

Sleep problems in fragile X syndrome: Cross-sectional analysis of a large clinic-based cohort

Fragile X syndrome (FXS), the leading cause of inherited intellectual disability and autism spectrum disorder, is associated with multiple neurobehavioral abnormalities including sleep difficulties. Nonetheless, frequency, severity, and consequences of sleep problems are still unclear. The Fragile X Online Registry with Accessible Research Database (FORWARD-version-3), including Clinician Report and Parent Report forms, was analyzed for frequency, severity, relationship with behavioral problems, and impact of sleep difficulties in a mainly pediatric cohort. A focused evaluation of sleep apnea was also conducted. Six surveyed sleep difficulties were moderately frequent (~23%-46%), relatively mild, affected predominantly younger males, and considered a problem for 7%-20% of families. Snoring was more prevalent in older individuals. All sleep difficulties were associated with irritability/aggression and most also to hyperactivity. Only severe snoring was correlated with sleep apnea (loud snoring: 30%; sleep apnea: 2%-3%). Sleep difficulties are prevalent in children with FXS and, although they tend to be mild, they are associated with behavioral problems and negative impact to families. Because of its cross-sectional nature, clinic-origin, use of ad hoc data collection forms, and lack of treatment data, the present study should be considered foundational for future research aiming at better recognition and management of sleep problems in FXS.

Breathing Abnormalities During Sleep and Wakefulness in Rett Syndrome: Clinical Relevance and Paradoxical Relationship With Circulating Pro-oxidant Markers

Background

Breathing abnormalities are common in Rett syndrome (RTT), a pervasive neurodevelopmental disorder almost exclusively affecting females. RTT is linked to mutations in the methyl-CpG-binding protein 2 (MeCP2) gene. Our aim was to assess the clinical relevance of apneas during sleep-wakefulness cycle in a population with RTT and the possible impact of apneas on circulating oxidative stress markers.

Methods

Female patients with a clinical diagnosis of typical RTT (n = 66), MECP2 gene mutation, and apneas were enrolled (mean age: 12.5 years). Baseline clinical severity, arterial blood gas analysis, and red blood cell count were assessed. Breathing was monitored during the wakefulness and sleep states (average recording time: 13 ± 0.5 h) with a portable polygraphic screening device. According to prevalence of breath holdings, the population was categorized into the wakefulness apnea (WA) and sleep apnea (SA) groups, and apnea-hypopnea index (AHI) was calculated. The impact of respiratory events on oxidative stress was assessed by plasma and intra-erythrocyte non-protein-bound iron (P-NPBI and IE-NPBI, respectively), and plasma F2-isoprostane (F2-IsoP) assays.

Results

Significant prevalence of obstructive apneas with values of AHI &gt; 15 was present in 69.7% of the population with RTT. The group with SA showed significantly increased AHI values &gt; 15 (p = 0.0032), total breath holding episodes (p = 0.007), and average SpO2 (p = 0.0001) as well as lower nadir SpO2 (p = 0.0004) compared with the patients with WAs. The subgroups of patients with WA and SA showed no significant differences in arterial blood gas analysis variables (p &gt; 0.089). Decreased mean cell hemoglobin (MCH) (p = 0.038) was observed in the group with WAs. P-NPBI levels were significantly higher in the group with WA than in that with SAs (p = 0.0001). Stepwise multiple linear regression models showed WA being related to nadir SpO2, average SpO2, and P-NPBI (adjusted R2 = 0.613, multiple correlation coefficient = 0.795 p &lt; 0.0001), and P-NPBI being related to average SpO2, blood PaCO2, red blood cell mean corpuscular volume (MCV), age, and topiramate treatment (adjusted R2 = 0.551, multiple correlation coefficient = 0.765, p &lt; 0.0001).

Conclusion

Our findings indicate that the impact of apneas in RTT is uneven according to the sleep-wakefulness cycle, and that plasma redox active iron represents a potential novel therapeutic target.

Sleep Disorders in Rett Syndrome and Rett-Related Disorders: A Narrative Review

Rett Syndrome (RTT) is a rare and severe X-linked developmental brain disorder that occurs primarily in females, with a ratio of 1:10.000. De novo mutations in the Methyl-CpG Binding protein 2 (MECP2) gene on the long arm of X chromosome are responsible for more than 95% cases of classical Rett. In the remaining cases (atypical Rett), other genes are involved such as the cyclin-dependent kinase-like 5 (CDKL5) and the forkhead box G1 (FOXG1). Duplications of the MECP2 locus cause MECP2 duplication syndrome (MDS) which concerns about 1% of male patients with intellectual disability. Sleep disorders are common in individuals with intellectual disability, while the prevalence in children is between 16 and 42%. Over 80% of individuals affected by RTT show sleep problems, with a higher prevalence in the first 7 years of life and some degree of variability in correlation to age and genotype. Abnormalities in circadian rhythm and loss of glutamate homeostasis play a key role in the development of these disorders. Sleep disorders, epilepsy, gastrointestinal problems characterize CDKL5 Deficiency Disorder (CDD). Sleep impairment is an area of overlap between RTT and MECP2 duplication syndrome along with epilepsy, regression and others. Sleep dysfunction and epilepsy are deeply linked. Sleep deprivation could be an aggravating factor of epilepsy and anti-comitial therapy could interfere in sleep structure. Epilepsy prevalence in atypical Rett syndrome with severe clinical phenotype is higher than in classical Rett syndrome. However, RTT present a significant lifetime risk of epilepsy too. Sleep disturbances impact on child's development and patients' families and the evidence for its management is still limited. The aim of this review is to analyze pathophysiology, clinical features, the impact on other comorbidities and the management of sleep disorders in Rett syndrome and Rett-related syndrome.

Smith-Magenis Syndrome—Clinical Review, Biological Background and Related Disorders

Smith-Magenis syndrome (SMS) is a complex genetic disorder characterized by distinctive physical features, developmental delay, cognitive impairment, and a typical behavioral phenotype. SMS is caused by interstitial 17p11.2 deletions (90%), encompassing multiple genes and including the retinoic acid-induced 1 gene (RAI1), or by pathogenic variants in RAI1 itself (10%). RAI1 is a dosage-sensitive gene expressed in many tissues and acting as transcriptional regulator. The majority of individuals exhibit a mild-to-moderate range of intellectual disability. The behavioral phenotype includes significant sleep disturbance, stereotypes, maladaptive and self-injurious behaviors. In this review, we summarize current clinical knowledge and therapeutic approaches. We further discuss the common biological background shared with other conditions commonly retained in differential diagnosis.

Caregivers' experience of sleep management in Smith-Magenis syndrome: a mixed-methods study

BACKGROUND

Smith-Magenis syndrome (SMS) is a rare genetic syndrome associated with a unique profile of early morning waking and daytime sleepiness. Children with SMS evidence high rates of self-injury and aggression and have a preference for adult over peer attention, with strong motivation to interact with a particular caregiver. In addition, people with SMS have lower adaptive functioning skills relative to cognitive abilities and demonstrate high levels of impulsivity. Taken together, these factors may result in individuals being awake overnight requiring vigilant caregiver supervision. Despite these complexities, no study has described the strategies caregivers take to keep their children with SMS safe overnight or considered the impact of these experiences on caregivers or the wider family.

METHODS

The current study used a mixed-methods approach to consider sleep management strategies and challenges for caregivers of people with SMS at different ages. Caregivers completed an international online survey about sleep management and related difficulties, use of interventions and access to services and support. Semi-structured interviews were conducted with 14 caregivers in the UK to increase understanding of caregiver experiences and priorities for change in the UK context. Interviews were transcribed verbatim and coded using thematic analysis.

RESULTS

Evidence from the online survey (n = 40) revealed wide-ranging impacts of poor sleep on the person with SMS and the wider family. Only 5% of caregivers reported that the sleep problems had no impact on their child, and 76% reported a moderately or extremely significant impact on themselves. For some individual caregivers, sleep management difficulties improved over time whereas for others no change was reported. Weekly respite emerged as the ideal provision for 49% of caregivers, although only 14% had access to this. The majority of caregivers (54%) received no respite. Thematic analysis of qualitative interviews revealed interactions between aspects of the behavioural phenotype of SMS which may contribute to complex and unusual presentations in relation to sleep management and safety.

CONCLUSIONS

Caregivers' priorities for sleep management and support were delineated, with key implications for services in terms of the use of SMS-sensitive strategies and respite provision.

Sleep disturbances correlate with behavioral problems among individuals with Wiedemann-Steiner syndrome

Wiedemann-Steiner syndrome (WSS) is a rare genetic disorder caused by mutation in KMT2A and characterized by neurodevelopmental delay. This study is the first prospective investigation to examine the sleep and behavioral phenotypes among those with WSS through parent-informant screening inventories. A total of 24 parents of children/adults with WSS (11F, Mean age = 12.71 years, SD = 8.17) completed the Strengths and Difficulties Questionnaire (SDQ) and 22 of these caregivers also completed the Modified Simonds and Parraga Sleep Questionnaire (MSPSQ). On average, the majority of those with WSS (83%) were rated to show borderline to clinical level of behavioral difficulties on the SDQ. Approximately 83% were rated in these ranges for hyperactivity, 63% for emotional problems, and 50% for conduct problems. When applying prior published clinical cut-off for risk of sleep disturbance among those with neurodevelopmental disorders, over 80% of our sample exceeded this limit on the MSPSQ. Largely, caregivers' ratings suggested restless sleep, rigid bedtime rituals, sleep reluctance and breathing through the mouth in sleep were most consistent problems observed. Partial correlations between sleep and behavioral domains showed elevated emotional problems were associated with parasomnia characteristics after controlling for age. Daytime drowsiness and activity were associated with more hyperactivity. Those with more night waking problems and delayed sleep onset were rated to show more severe conduct problems. Overall, these findings suggest dysfunctional sleep behaviors, hyperactivity, and affective problems are part of the neurobehavioral phenotype of WSS. Routine clinical care for those affected by WSS should include close monitoring of sleep and overactive behaviors.

Sleep in Children With Pallister Killian Syndrome: A Prospective Clinical and Videopolysomnographic Study

Objectives: Pallister-Killian syndrome (PKS) is a rare genetic disorder with multi-organ involvement caused by mosaic tetrasomy of chromosome 12p. Although many caregivers report the presence of impaired sleep in their children, there are no clear data in the literature on this issue and no systematic study has ever been performed. With this study, we aimed to characterize the features of sleep in Pallister-Killian syndrome and identify the possible influence of clinical and demographic features. Moreover, our aim was to verify the effectiveness of conventional screening questionnaires in this particular group of patients.

Methods: We prospectively enrolled 14 patients aged 1–17 years in collaboration with PKS Kids Italia ONLUS. The Sleep Disturbance Scale for Children (SDSC) questionnaire was administered to caregivers. Then, video polysomnography (VPSG) of at least 24 h was performed and results were compared with a same-aged control group.

Results: A total of 92% of patients had abnormal SDSC scores, extremely high in the “disorder of initiating and maintaining sleep” (DIMS) and “sleep breathing disorders” (SBD) subscales. VPSG showed a significantly impaired macrostructure in PKS patients, with a higher Arousal Index (p < 0.00001) and percentage of time spent in N3 (p < 0.00001), and reduced Sleep Efficiency (p = 0.0006). After dividing both PKS and controls into two groups based on median age, some peculiarities emerged: the younger group had higher Awakenings Index (p = 0.0207) and percentage of time spent in N1 (p = 0.015) while the older group showed higher time in bed (TIB) (p = 0.0485), compared with controls. Due to poor compliance, the Apnea-Hypopnea Index (AHI) was evaluated only for 10 PKS children, being significantly increased (p = 0.0427) compared with controls. SBD subscale scores in SDSC were significantly related to AHI values in VPSG (p = 0.0099).

Conclusions: This study constitutes the first attempt to describe the sleep pattern in PKS. Despite small numbers due to the rarity of the syndrome, our VPSG results confirm the high prevalence of sleep disorders (SDs) in these patients. It is therefore essential to investigate and treat them. The SDSC scale is a good screening tool for early detection also in these patients, with particular sensitivity in detecting breathing disorders.

Sleep disorders and neuropsychiatric disorders in a pediatric sample of tuberous sclerosis complex: a questionnaire-based study

OBJECTIVE AND BACKGROUND

Sleep disorders (SD) are very common in childhood, especially in certain genetic syndromes. Tuberous Sclerosis Complex (TSC) is a genetic syndromesassociated with a high rate of SD, although these are still under-recognized. The aim of this study was to assess the prevalence of SD in TSC, and to evaluate the relationship between sleep, epilepsy and TSC-associated neuropsychiatric disorders (TAND).

METHODS

We administered the Sleep Disturbance Scale for Children (SDSC) and the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD) to parents of 177 children with TSC referring to different Italian centers. We also collected information on epilepsy and TAND.

RESULTS

SDSC score was positive in 59.3% of patients, being positive in 30.4% of patients without and in 63.6% of those with epilepsy (p = 0.005). However, in a multivariate logistic model considering antiseizure medications and nocturnal seizures, epilepsy ceased to be a significant risk factor for positive SDSC (OR = 2.4; p = 0.17). As for TAND, SDSC was positive in 67.9% of patients with and in 32.5% of those without TAND (p < 0.001). After adding in a multivariate logistic model active epilepsy, age, and pharmacotherapies, TAND continued to be a significant risk factor for positive SDSC (p = 0.01, OR = 1.11).

CONCLUSIONS

Our results revealed a high prevalence of SD in children with TSC. Epilepsy didn't increase the risk for SD, while a very strong association was found with TAND. An early detection of SD is of utmost importance in order to plan an individualized treatment, that in some cases might also ameliorate behavior and attention.

Sleep and daytime behavior in individuals with Christianson Syndrome

BACKGROUND

The objectives of this study were to: 1) characterize the sleep behaviors and symptoms of individuals with Christianson Syndrome (CS) by means of validated questionnaires; and 2) determine their associations with daytime emotional and behavioral symptoms in this population.

METHODS

Participants included 16 boys genetically diagnosed with CS, between 2.5 and 40 years of age (M = 14.5 ± 8.08). Parents completed questionnaires regarding the sleep, daytime behavior, and health of their child.

RESULTS

Of the participants, 31% did not obtain the recommended amount of sleep for their age, 43% experienced a prolonged sleep latency, and 88% had a clinical or sub-clinical score for at least one subscale of the Sleep Disturbance Scale for Children (SDSC). Specific problems detected included insomnia, sleep-wake transition disorders, periodic limb movements in sleep, and sleep related breathing disorders. About half of the participants manifested emotional and behavioral problems at clinical levels. Higher levels of sleep disturbances were associated with higher levels of behavioral and emotional daytime symptoms.

CONCLUSIONS

Sleep problems are common in individuals with CS and are associated with daytime behavioral and emotional symptoms.

Sleep, Behavior, and Adaptive Function in KAT6A Syndrome

KAT6A syndrome is a Mendelian Disorder of the Epigenetic Machinery characterized by intellectual disability and profound expressive language impairment. This study aimed to further characterize behavior and sleep in this syndrome. 26 participants between the ages of 3 and 35 years with KAT6A syndrome were assessed via parental informant using the Adaptive Behavior Assessment System version 3 (ABAS-3), Achenbach Child or Adult Behavior Checklist (CBCL/ABCL), and a Modified Simonds and Parraga Sleep Questionnaire (MSPSQ). The ABAS reports conceptual, social, and practical domains of adaptive function as well as a general composite score for adaptive function. The CBCL/ABCL is an inventory that measures internalizing, externalizing, and DSM-oriented problem domains. The MSPSQ is a mix of qualitative and quantitative sleep information that includes behavioral and medical sleep problems. Mean values for all domains of the ABAS-3 were in the extremely low range. Additionally, sleep was very dysfunctional in this cohort. Sixty percent of respondents reported feeling there was a sleep problem, 64% take medication for sleep, and 68% have sought treatment or advice for sleep. Only 12% of these participants have sleep apnea suggesting that sleep problems in this disorder are unrelated to sleep-disordered breathing. Interestingly, there were extremely low rates of all types of behaviors reported among participants on the CBCL/ABCL. No significant differences were seen based on genotype grouping in adaptive function, sleep, or behavior. This study further delineates the phenotype of the KAT6A syndrome and emphasizes the need for supports for adaptive functioning as well as detailed attention to the behavioral aspects of sleep in this condition.