Enabling successful life engagement in young people with ADHD: new components beyond adult models of recovery.

PURPOSE: To examine the lived experiences of young people successfully managing life with ADHD and investigate the applicability of adult models of Recovery to these individuals. METHODS: Twenty-seven young people aged 15-31 years participated in qualitative interviews. Participants' success was indicated by employment, school attendance, absence of acute mental health episodes, or absence of chronic alcohol or drug use. Thematic analysis identified specific components of their life successes and challenges. RESULTS: The emergent framework comprised four elements: (i) Recovernance (RE) (a portmanteau merging 'Recovery' and 'Maintenance'; ongoing adjustment to maintain one's personal best without an end point); (ii) Personal Optimization (PO) (continuously striving to maximize function and adjust one's goals given fluctuating impairments and internal resources); (iii) Self (S) (facing internal challenges and developing internal resilience); and (iv) Environment (E) (facing external challenges and fostering external resilience). These four elements yielded the acronym 'REPOSE'. CONCLUSIONS: Recovery in young people with ADHD was not a linear journey, with many missteps leading to greater self-knowledge, life skills and mastery. Progress was leveraged on securely anchored internal and external resilience factors against the prospect of setbacks. Findings provide new concepts and novel lexicons to extend existing concepts in Recovery. Implications for rehabilitationCounselling and therapy for young people with ADHD should foster self-understanding, goal setting and self-vigilance as an ongoing process to build their capacity to tackle setbacks and adversities.Counselling and therapy for young people with ADHD focus on a strengths-based approach building internal and external resources, such as developing skills and establishing social connections that build infrastructure in the environment for meaningful participation.

Modifiable child and caregiver factors that influence community participation among children with Down syndrome.

PURPOSE: To investigate modifiable child and caregiver factors influencing community participation among children with Down syndrome. METHODS: Cross-sectional data from a study investigating quality of life of children with intellectual disability were analysed. Participants were caregivers of 89 children with Down syndrome (54 females; 83 school attenders) (mean age 11 y 1 mo; SD 4 y 1 mo). Components of participation (attendance, involvement) were measured using the Participation and Environment Measure for Children and Youth, community module. Caregiver factors were time, mood, transport, and disability funding. Child factors were sleep, behaviour, communication, and health. Multivariate linear regression analyses examined if (i) caregiver factors were associated with attendance and (ii) child factors were associated with involvement. RESULTS: Increased caregiver time availability was associated with higher frequency of attendance. Higher frequency of attendance was associated with greater child involvement, and having a sleep breathing disorder and less verbal communication ability was associated with less child involvement. These factors combined explained 21% of the variance. CONCLUSIONS: Children with Down syndrome who participated in the community more frequently enjoyed greater involvement. Supporting participation of children with poorer verbal communication and/or sleep breathing disorders could further the participation of children with Down syndrome.Implications for rehabilitationChildren with Down syndrome who more frequently attended opportunities for participation were more likely to be involved in those experiences.Healthcare providers and educators could foster involvement in participation opportunities of children with poorer verbal ability by supporting the development of prerequisite communication strategies.Rehabilitation programs and policies pertaining to accessibility of community activities need to align with modifiable determinants of participation in children, including availability of caregivers' time.

Comorbidities and quality of life in children with intellectual disability.

BACKGROUND: Many children with intellectual disability live with medical comorbidities. This study examined the impacts of comorbidities on quality of life (QOL) of children with intellectual disabilities and whether impacts varied with caregiver perceptions that medical needs had been met. METHODS: Primary caregivers of 447 children (aged 5-19 years) with an intellectual disability reported on their child's medical comorbidities and the extent to which they perceived their child's medical needs had been met in a cross-sectional observational study. The Quality of Life Inventory-Disability was used to measure QOL on a 100-point scale. Linear regression models including interaction terms were used to evaluate their associations. RESULTS: Parent-reported recurrent child pain (-4.97, 95% CI -8.21, -1.72), night-time sleep disturbances (-4.98, 95% CI -7.23, -2.73), daytime somnolence (-8.71, 95% CI -11.30, -2.73), seizures that occurred at least weekly (-7.59, 95% CI -13.50, -1.68) and conservatively managed severe scoliosis (-7.39, 95% CI -12.97, -1.81) were negatively associated with child QOL. Despite the majority of parents (~70%) perceiving that their child's medical needs had been met to a great extent, this did not significantly moderate the association between any comorbidities and QOL. CONCLUSIONS: Comorbidities were common and had marked associations with QOL. Evaluation and management of pain and sleep disturbance continue to be high priorities in improving QOL of young people with intellectual disabilities. Further research on the optimal methods of managing these comorbidities is warranted.

Functioning, participation, and quality of life in children with intellectual disability: an observational study.

AIMS: To investigate associations between functioning, community participation, and quality of life (QoL) and identify whether participation mediates the effects of functioning on QoL. METHOD: The caregivers of 435 children (211 females, 224 males; mean age 12y; SD 3y 11mo; age range 5-18y) with intellectual disability and autism spectrum disorder, cerebral palsy, Down syndrome, or Rett syndrome reported on their child's functioning (dependence for managing personal needs, mobility, communication, eye contact when speaking), frequency of participation, and QoL. Linear regression and mediation analyses were used to evaluate the relationships between child functioning, participation, and QoL. RESULTS: Children with greater dependency for managing personal needs and limited eye contact when speaking experienced poorer QoL. Less impaired functioning was associated with more frequent participation, which, in turn, was associated with a 3-point gain in QoL for each additional point in frequency of participation (coefficient=2.67, 95% confidence interval 1.56-3.78). The effect of impaired functioning on QoL was partially mediated by participation in children with greater dependency in managing personal needs and those with mildly impaired communication. INTERPRETATION: Greater levels of impairments with poorer functioning, notably a high level of dependence, were associated with poorer QoL. Poorer QoL can be partly explained by less frequent community participation.

Prevalence estimates of mental health problems in children and adolescents with intellectual disability: A systematic review and meta-analysis.

BACKGROUND: Children and adolescents with intellectual disability are at risk of developing psychiatric symptoms and disorders; yet, the estimates reported in the literature have been inconsistent, presenting a potential barrier for service planning and delivery. Sources of variability could arise from differences in measurement instruments as well as subgroup membership by severity of intellectual disability, gender and age. This systematic review aimed to address these gaps. METHOD: MEDLINE and PsycINFO databases were searched from inception to 2018 and selected studies were reviewed. Studies were included if they reported point prevalence estimates of mental health symptomology or diagnoses in a general population of 6- to 21-year-old individuals with intellectual disability. The Joanna Briggs Institute Prevalence Critical Appraisal Checklist was applied to eligible papers to appraise their scientific strength. Pooled prevalence for mental health symptomology was determined using a random-effects meta-analysis. RESULTS: A total of 19 studies were included, including 6151 children and adolescents. The pooled prevalence estimate captured by the Developmental Behaviour Checklist was 38% (95% confidence interval = [31, 46]), contrasting with 49% (95% confidence interval = [46, 51]) captured by the Child Behaviour Checklist; both rates were higher than a non-intellectual disability population. Severity of intellectual disability did not significantly influence the Developmental Behaviour Checklist risks. Insufficient data were available to conduct statistical analyses on the effects of age, gender and socioeconomic status. Of diagnosed psychiatric disorders, attention deficit/hyperactivity disorder (30%), conduct disorder (3-21%) and anxiety disorders (7-34%) were the most prevalent conditions. CONCLUSION: This review consists of the largest sample hitherto evaluated. In the intellectual disability population, mental health comorbidities could be better detected by a symptom phenotype than a psychiatric diagnostic phenotype. Crucially, future research needs to address the effect of measurement validity in the intellectual disability population. Estimated prevalence rates were high compared to the general population, indicating the importance of systematic screening, case detection and appropriate management.

Reliability of the Quality of Life Inventory-Disability Measure in Children with Intellectual Disability.

OBJECTIVE: To assess responsiveness and reproducibility using the estimates of test-retest reliability for the Quality of Life Inventory-Disability (QI-Disability), accounting for changes in child health and parental stress. METHOD: Quality of Life Inventory-Disability was administered twice over a 1-month period to a sample of 55 primary caregivers of children (aged 5-19 years) with intellectual disability. Caregivers also reported their child's physical and mental health and completed a 4-item Perceived Stress Scale to assess parental stress. Fixed-effects linear regression models examined responsiveness of QI-Disability to the reported change in child health and parental stress. Reliability was then assessed using intraclass correlations (ICCs) calculated from QI-Disability scores adjusted for changes in child health and parental stress. RESULTS: Five of 7 unadjusted ICC values indicated at least moderate agreement (>0.70), and 2 values indicated fair agreement. After accounting for changes in child health and parental stress, adjusted ICC values showed substantial agreement for the total QI-Disability score and 4 domain scores (adjusted ICC ≥ 0.80). Adjusted ICC scores indicated moderate agreement for the Physical Health domain (adjusted ICC = 0.68) and fair agreement for the Positive Emotions domain (adjusted ICC = 0.58). Improvements in a child's physical health rating were associated with higher total, Physical Health, and Positive Emotion domain scores, whereas improvements in mental health were associated with higher total and Negative Emotions domain scores, indicating better quality of life. Changes in parental stress did not have a statistically significant relationship with quality of life. CONCLUSION: Satisfactory test-retest reliability was shown. Preliminary evidence indicates that QI-Disability is responsive to changes in child health, but not to differing levels of parental stress.

Systematic Review and Meta-analysis: Mental Health in Children With Neurogenetic Disorders Associated With Intellectual Disability.

OBJECTIVE: The behavioral phenotype of neurogenetic disorders associated with intellectual disability often includes psychiatric comorbidity. The objectives of this systematic review and meta-analysis were to systematically review the prevalence of psychiatric disorders and symptoms in children and adolescents with these disorders and compare phenotypic signatures between syndromes. METHOD: MEDLINE and PsycINFO databases were searched for articles from study inception to December 2018. Eligible articles were peer reviewed, were published in English, and reported prevalence data for psychiatric disorders and symptoms in children and adolescents aged 4 to 21 years using a formal psychiatric assessment or a standardized assessment of mental health symptoms. Pooled prevalence was determined using a random-effects meta-analysis in studies with sufficient data. Prevalence estimates were compared with general population data using a test of binomial proportions. RESULTS: Of 2,301 studies identified for review, 39 articles were included in the final pool, which provided data on 4,039 children and adolescents. Ten syndromes were represented, and five were predominant: Down syndrome, 22q11.2 deletion syndrome, fragile X syndrome, Williams syndrome, and Prader-Willi syndrome. The Child Behavior Checklist was the most commonly used assessment tool for psychiatric symptoms. The pooled prevalence with total scores above the clinical threshold was lowest for Down syndrome (32% [95% confidence interval, 19%-44%]) and highest for Prader-Willi syndrome (74% [95% CI, 65%-82%]) with each syndrome associated with significantly higher prevalence than in the general population. Parallel trends were observed for the internalizing and externalizing domains and social subscale scores. CONCLUSION: Differential vulnerability for psychiatric phenotype expression across the disorders was observed. Syndromes with higher levels of social ability or competence appear to offer relative protection against developing psychopathology. This preliminary finding merits further exploration.

Using directed-content analysis to identify a framework for understanding quality of life in adults with Rett syndrome.

Purpose: Rett syndrome (RTT) is a rare neurodevelopmental disorder mainly affecting females and is caused by a mutation in the MECP2 gene. Recent research identified the domains of quality of life (QOL) important for children with RTT but there has been no investigation of domains important for adults. This qualitative study explored QOL in adults with RTT and compared domains with those previously identified for children.Methods: The sample comprised parents and/or primary caregivers of 20 adults, aged 18-38 years, who were registered with the Australian Rett Syndrome Database. Semi-structured telephone interviews were conducted to investigate aspects of life that were observed to be satisfying or challenging. Data were analyzed using directed content analysis, based on existing QOL domains for children with RTT that related to health and wellbeing, daily activities, and community immersion and services.Results: Each of the domains identified for children with RTT was represented in the adult dataset, with no new domains emerging.Conclusion: This is the first study to identify QOL domains important for adults with RTT. Health and therapy needs are ongoing during adulthood but services may be limited. Findings will guide choice of an appropriate QOL measure for this group.IMPLICATIONS FOR REHABILITATIONKnowing the important domains of quality of life enables clinicians and service providers to systematically review and address key management issues.Despite a high level of dependency and sometimes poor health, parent caregivers perceive potential for strong quality of life in adulthood.Services that maintain functional skills and health throughout the lifespan are valued for their support of quality of life in adults with Rett syndrome.

Content validation of the Quality of Life Inventory-Disability.

BACKGROUND: Focus is shifting to better understand the lived experiences of children with intellectual disability in relation to their quality of life (QOL). Yet no available QOL measures are grounded in the domains important for this population. We previously conducted qualitative parent caregiver interviews identifying QOL domains in children with intellectual disability to constitute a new measure of QOL. This study describes the content validity of the Quality of Life Inventory-Disability (QI-Disability), a parent-report measure developed for children with intellectual disability. METHODS AND RESULTS: Questionnaire items were extracted from a qualitative dataset of 77 parent caregiver interviews. To establish content validation, a draft of QI-Disability was administered to 16 parent caregivers of children with intellectual disability (Down syndrome, Rett syndrome, cerebral palsy, or autism spectrum disorder). Parents participated in a cognitive interviewing procedure known as the "think-aloud" method. The process of item generation, cognitive debriefing, and refinement of QI-Disability prior to its pilot testing are described. A conceptual framework is presented. CONCLUSIONS: Satisfactory content validity is reported, where ongoing consumer feedback shaped the dataset from which the final items were selected. Use of QI-Disability for children with intellectual disability will allow for greater insight into service utility and targeted intervention.

Parent-observed thematic data on quality of life in children with autism spectrum disorder.

Domains of quality of life in children with autism spectrum disorder have not previously been explored and there has been no quality of life measure developed for this population. Our study investigated parent observations to identify the domains important to children with autism spectrum disorder who also had an intellectual disability. In all, 21 parents (19 mothers, 2 fathers) of children with autism spectrum disorder (aged 6-17 years) participated in a qualitative study to discuss their child's quality of life. Thematic analysis using a grounded theory framework was conducted and 10 domains emerged in relation to health and well-being, capacity to perform and develop skills in daily life, and connections with the community and environment. Unique aspects of quality of life included varying levels of social desire, consistency of routines, and time spent in nature and the outdoors, which are not comprehensively captured in existing measures. Parent observations provide an initial framework for understanding quality of life in autism spectrum disorder and support the development of a new measure for this population.

Psychometric properties of the Quality of Life Inventory-Disability (QI-Disability) measure.

PURPOSE: Children with intellectual disability encounter daily challenges beyond those captured in current quality of life measures. This study evaluated a new parent-report measure for children with intellectual disability, the Quality of Life Inventory-Disability (QI-Disability). METHODS: QI-Disability was administered to 253 primary caregivers of children (aged 5-18 years) with intellectual disability across four diagnostic groups: Rett syndrome, Down syndrome, cerebral palsy or autism spectrum disorder. Exploratory and confirmatory factor analyses were conducted and goodness of fit of the factor structure assessed. Associations between QI-Disability scores, and diagnostic and age groups were examined with linear regression. RESULTS: Six domains were identified: physical health, positive emotions, negative emotions, social interaction, leisure and the outdoors, and independence. Goodness-of-fit statistics were satisfactory and similar for the whole sample and when the sample was split by ability to walk or talk. On 100 point scales and compared to Rett syndrome, children with Down syndrome had higher leisure and the outdoors (coefficient 10.6, 95% CI 3.4,17.8) and independence (coefficient 29.7, 95% CI 22.9, 36.5) scores, whereas children with autism spectrum disorder had lower social interaction scores (coefficient - 12.8, 95% CI - 19.3, - 6.4). Scores for positive emotions (coefficient - 6.1, 95% CI - 10.7, - 1.6) and leisure and the outdoors (coefficient 5.4, 95% CI - 10.6, - 0.1) were lower for adolescents compared with children. CONCLUSIONS: Initial evaluation suggests that QI-Disability is a reliable and valid measure of quality of life across the spectrum of intellectual disability. It has the potential to allow clearer identification of support needs and measure responsiveness to interventions.

A framework for understanding quality of life domains in individuals with the CDKL5 deficiency disorder.

The CDKL5 deficiency disorder (CDD) is a rare condition caused by spontaneous mutations on the cyclin-dependent kinase-like 5 (CDKL5) gene. It is a severe and complex disability that markedly affects the individual's health and wellbeing. This study aimed to identify the quality of life (QOL) domains important for individuals with CDD. Twenty-five parents of individuals registered in the International CDKL5 Disorder Database participated in semi-structured telephone interviews to explore areas that supported or challenged their child's QOL. Rett syndrome (RTT) is another severe genetically-caused neurodevelopmental disorder but is generally less severe than CDD. Qualitative data were analysed using directed content analysis, based on previously identified QOL domains for RTT that related to health and wellbeing, daily activities and community immersion and services. Each of the domains identified for RTT was represented in the CDD dataset overall and when the dataset was divided into three age groups: 3-5 years old; 6-18 years old; and older than 18 years. This is the first study to conceptualise factors important for individuals with CDD. Findings from this study will guide health professionals and other service providers who support individuals with CDD and will offer insight into choosing appropriate QOL instruments when measuring outcomes for this group.

The prevalence of mental health disorders and symptoms in children and adolescents with cerebral palsy: a systematic review and meta-analysis.

AIM: Mental health conditions and problems are often reported in children and adolescents with cerebral palsy (CP). A systematic review was undertaken to describe their prevalence. METHOD: MEDLINE and PsycINFO databases from 1996 to 2016 were searched and reference lists of selected studies were reviewed. Studies were included if they reported point prevalence of mental health diagnoses or symptoms in a general population of children and/or adolescents with CP. Pooled prevalence for mental health symptoms was determined using a random effects meta-analysis. RESULTS: Of the 3158 studies identified, eight met the inclusion criteria. Mental health disorders were diagnosed by psychiatric interview in one study, giving a prevalence of 57% (32 out of 56 children). The remaining seven studies (n=1715 children) used parent-report mental health screening tools. The pooled prevalence for mental health symptoms using the Strengths and Difficulties Questionnaire (n=5 studies) was 35% (95% confidence interval [CI] 20-61) and using the Child Behavior Checklist (n=2 studies) was 28% (95% CI 22-36). Evidence was characterized by a moderate level of bias. INTERPRETATION: More studies are needed to ascertain the prevalence of mental health disorders. Mental health symptoms are common and mental health evaluations should be incorporated into multidisciplinary assessments for these children. WHAT THIS PAPER ADDS: Children with cerebral palsy and intellectual disability have a higher risk of mental health symptoms. The prevalence of mental health symptoms for age and severity groups is unclear.

Autonomic breathing abnormalities in Rett syndrome: caregiver perspectives in an international database study.

BACKGROUND: Rett syndrome is a severe neurodevelopmental disorder associated with mutations in the MECP2 gene. Irregular breathing patterns and abdominal bloating are prominent but poorly understood features. Our aims were to characterize the abnormal breathing patterns and abdominal bloating, investigate the distribution of these by age and mutation type and examine their impact and management from a caregiver perspective. METHODS: We invited previously recruited families from the International Rett Syndrome Study to complete a web-based questionnaire concerning their family member with Rett syndrome aged between 2 and 57 years. We used logistic regression to investigate presence, frequency and impact of breath-holding, hyperventilation, or abdominal bloating by age group and mutation type. Age of onset for both breathing abnormalities was investigated using time-to-onset analysis, and the Kaplan-Meier method was used to estimate the failure function for the study sample. Descriptive statistics were used to characterize the management of irregular breathing. RESULTS: Questionnaires were returned by 413/482 (85.7%) families. Breath-holding was reported for 68.8%, hyperventilation for 46.4% and abdominal bloating for 42.4%. Hyperventilation was more prevalent and frequent in those younger than 7 years of age and abdominal bloating in those aged over 20 years. Onset of breathing irregularities usually occurred during early childhood. Caregivers perceived that daily life was considerably impacted for almost half (44.1%) of those with abdominal bloating and in just over than a third of those with breath-holding (35.8%) or hyperventilation (35.1%). Although perceived impact was broadly comparable between age and mutation groups for breath-holding, hyperventilation and abdominal bloating, girls and women with a p.Arg294* mutation were considered to be more affected by all three conditions. Only 31 individuals had received medically prescribed treatments including 12 different medications, added oxygen, rebreathing apparatus or non-invasive ventilation. CONCLUSIONS: Autonomic disturbances are prevalent and burdensome in Rett syndrome. This information may guide the design of inclusion criteria and outcome measures for clinical intervention trials targeting autonomic abnormalities. Further investigation of available treatments is necessary to delineate evidence-based management pathways.

Qualitative Analysis of Parental Observations on Quality of Life in Australian Children with Down Syndrome.

OBJECTIVE: There are many challenges to health, functioning, and participation for children with Down syndrome; yet, the quality-of-life (QOL) domains important for this group have never been clearly articulated. This study investigated parental observations to identify QOL domains in children with Down syndrome and determined whether domains differed between children and adolescents. METHODS: The sample comprised 17 families whose child with Down syndrome was aged 6 to 18 years. Primary caregivers took part in semistructured telephone interviews to explore aspects of their child's life that were satisfying or challenging. Qualitative thematic analysis was implemented using a grounded theory framework to identify domains. The coded data set was divided into 2 groups (childhood and adolescence) at 3 age cut points to observe whether differences existed between the coded domains and domain elements: (1) 6 to 11 years with 12 to 18 years; (2) 6 to 13 years with 14 to 18 years; and (3) 6 to 15 years with 16 to 18 years. RESULTS: Eleven domains were identified: physical health, behavior and emotion, personal value, communication, movement and physical activity, routines and predictability, independence and autonomy, social connectedness and relationships, variety of activities, nature and outdoors, and access to services. No differences in domains and domain elements were identified across childhood and adolescence. CONCLUSION: Our data form a preliminary framework from which to design investigations of the child's perspectives on life quality and suggest a range of necessary supports and services.

Impacts of caring for a child with the CDKL5 disorder on parental wellbeing and family quality of life.

BACKGROUND: Although research in this area remains sparse, raising a child with some genetic disorders has been shown to adversely impact maternal health and family quality of life. The aim of this study was to investigate such impacts in families with a child with the CDKL5 disorder, a newly recognised genetic disorder causing severe neurodevelopmental impairments and refractory epilepsy. METHODS: Data were sourced from the International CDKL5 Disorder Database to which 192 families with a child with a pathogenic CDKL5 mutation had provided data by January 2016. The Short Form 12 Health Survey Version 2, yielding a Physical Component Summary and a Mental Component Summary score, was used to measure primary caregiver's wellbeing. The Beach Center Family Quality of Life Scale was used to measure family quality of life. Linear regression analyses were used to investigate relationships between child and family factors and the various subscale scores. RESULTS: The median (range) age of the primary caregivers was 37.0 (24.6-63.7) years and of the children was 5.2 (0.2-34.1) years. The mean (SD) physical and mental component scores were 53.7 (8.6) and 41.9 (11.6), respectively. In mothers aged 25-54 years the mean mental but not the physical component score was lower than population norms. After covariate adjustment, caregivers with a tube-fed child had lower mean physical but higher mean mental component scores than those whose child fed orally (coefficient = -4.80 and 6.79; p = 0.009 and 0.012, respectively). Child sleep disturbances and financial hardship were negatively associated with the mental component score. The mean (SD) Beach Center Family Quality of Life score was 4.06 (0.66) and those who had used respite services had lower scores than those who had not across the subscales. CONCLUSIONS: Emotional wellbeing was considerably impaired in this caregiver population, and was particularly associated with increased severity of child sleep problems and family financial difficulties. Family quality of life was generally rated lowest in those using respite care extensively, suggesting that these families may be more burdened by daily caregiving.

Determinants of sleep disturbances in Rett syndrome: Novel findings in relation to genotype.

Rett syndrome is a rare but severe neurological disorder associated with a mutation in the methyl CpG binding protein 2 (MECP2) gene. Sleep problems and epilepsy are two of many comorbidities associated with this disorder. This study investigated the prevalence and determinants of sleep problems in Rett syndrome using an international sample. Families with a child with a confirmed Rett syndrome diagnosis and a MECP2 mutation registered in the International Rett Syndrome Phenotype Database (InterRett) were invited to participate. Questionnaires were returned by 364/461 (78.9%) either in web-based or paper format. Families completed the Sleep Disturbance Scale for Children and provided information on the presence, nature, and frequency of their child's sleep problems. Multivariate multinomial regression was used to investigate the relationships between selected sleep problems, age group, and genotype and linear regression for the relationships between sleep disturbance scales and a range of covariates. Night waking was the most prevalent sleep problem affecting over 80% with nearly half (48.3%) currently waking often at night. Initiating and maintaining sleep was most disturbed for younger children and those with a p.Arg294* mutation. Severe seizure activity was associated with poor sleep after adjusting for age group, mutation type, and mobility. We were surprised to find associations between the p.Arg294* mutation and some sleep disturbances given that other aspects of its phenotype are milder. These findings highlight the complexities of aberrant MECP2 function in Rett syndrome and explain some of the variation in manifestation of sleep disturbances. © 2016 Wiley Periodicals, Inc.

Prevalence and onset of comorbidities in the CDKL5 disorder differ from Rett syndrome.

BACKGROUND: Initially described as an early onset seizure variant of Rett syndrome, the CDKL5 disorder is now considered as an independent entity. However, little is currently known about the full spectrum of comorbidities that affect these patients and available literature is limited to small case series. This study aimed to use a large international sample to examine the prevalence in this disorder of comorbidities of epilepsy, gastrointestinal problems including feeding difficulties, sleep and respiratory problems and scoliosis and their relationships with age and genotype. Prevalence and onset were also compared with those occurring in Rett syndrome. METHODS: Data for the CDKL5 disorder and Rett syndrome were sourced from the International CDKL5 Disorder Database (ICDD), InterRett and the Australian Rett syndrome Database (ARSD). Logistic regression (multivariate and univariate) was used to analyse the relationships between age group, mutation type and the prevalence of various comorbidities. Binary longitudinal data from the ARSD and the equivalent cross-sectional data from ICDD were examined using generalized linear models with generalized estimating equations. The Kaplan-Meier method was used to estimate the failure function for the two disorders and the log-rank test was used to compare the two functions. RESULTS: The likelihood of experiencing epilepsy, GI problems, respiratory problems, and scoliosis in the CDKL5 disorder increased with age and males were more vulnerable to respiratory and sleep problems than females. We did not identify any statistically significant relationships between mutation group and prevalence of comorbidities. Epilepsy, GI problems and sleep abnormalities were more common in the CDKL5 disorder than in Rett syndrome whilst scoliosis and respiratory problems were less prevalent. CONCLUSION: This study captured a much clearer picture of the CDKL5 disorder than previously possible using the largest sample available to date. There were differences in the presentation of clinical features occurring in the CDKL5 disorder and in Rett syndrome, reinforcing the concept that CDKL5 is an independent disorder with its own distinctive characteristics.