Interactions between the lipidome and genetic and environmental factors in autism.

Autism omics research has historically been reductionist and diagnosis centric, with little attention paid to common co-occurring conditions (for example, sleep and feeding disorders) and the complex interplay between molecular profiles and neurodevelopment, genetics, environmental factors and health. Here we explored the plasma lipidome (783 lipid species) in 765 children (485 diagnosed with autism spectrum disorder (ASD)) within the Australian Autism Biobank. We identified lipids associated with ASD diagnosis (n = 8), sleep disturbances (n = 20) and cognitive function (n = 8) and found that long-chain polyunsaturated fatty acids may causally contribute to sleep disturbances mediated by the FADS gene cluster. We explored the interplay of environmental factors with neurodevelopment and the lipidome, finding that sleep disturbances and unhealthy diet have a convergent lipidome profile (with potential mediation by the microbiome) that is also independently associated with poorer adaptive function. In contrast, ASD lipidome differences were accounted for by dietary differences and sleep disturbances. We identified a large chr19p13.2 copy number variant genetic deletion spanning the LDLR gene and two high-confidence ASD genes (ELAVL3 and SMARCA4) in one child with an ASD diagnosis and widespread low-density lipoprotein-related lipidome derangements. Lipidomics captures the complexity of neurodevelopment, as well as the biological effects of conditions that commonly affect quality of life among autistic people.

Autism-related dietary preferences mediate autism-gut microbiome associations.

There is increasing interest in the potential contribution of the gut microbiome to autism spectrum disorder (ASD). However, previous studies have been underpowered and have not been designed to address potential confounding factors in a comprehensive way. We performed a large autism stool metagenomics study (n = 247) based on participants from the Australian Autism Biobank and the Queensland Twin Adolescent Brain project. We found negligible direct associations between ASD diagnosis and the gut microbiome. Instead, our data support a model whereby ASD-related restricted interests are associated with less-diverse diet, and in turn reduced microbial taxonomic diversity and looser stool consistency. In contrast to ASD diagnosis, our dataset was well powered to detect microbiome associations with traits such as age, dietary intake, and stool consistency. Overall, microbiome differences in ASD may reflect dietary preferences that relate to diagnostic features, and we caution against claims that the microbiome has a driving role in ASD.

Cannabidiol and Neurodevelopmental Disorders in Children.

Neurodevelopmental and neuropsychiatric disorders (such as autism spectrum disorder) have broad health implications for children, with no definitive cure for the vast majority of them. However, recently medicinal cannabis has been successfully trialled as a treatment to manage many of the patients' symptoms and improve quality of life. The cannabinoid cannabidiol, in particular, has been reported to be safe and well-tolerated with a plethora of anticonvulsant, anxiolytic and anti-inflammatory properties. Lately, the current consensus is that the endocannabinoid system is a crucial factor in neural development and health; research has found evidence that there are a multitude of signalling pathways involving neurotransmitters and the endocannabinoid system by which cannabinoids could potentially exert their therapeutic effects. A better understanding of the cannabinoids' mechanisms of action should lead to improved treatments for neurodevelopmental disorders.

Analysis of common genetic variation and rare CNVs in the Australian Autism Biobank.

BACKGROUND: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition whose biological basis is yet to be elucidated. The Australian Autism Biobank (AAB) is an initiative of the Cooperative Research Centre for Living with Autism (Autism CRC) to establish an Australian resource of biospecimens, phenotypes and genomic data for research on autism. METHODS: Genome-wide single-nucleotide polymorphism genotypes were available for 2,477 individuals (after quality control) from 546 families (436 complete), including 886 participants aged 2 to 17 years with diagnosed (n = 871) or suspected (n = 15) ASD, 218 siblings without ASD, 1,256 parents, and 117 unrelated children without an ASD diagnosis. The genetic data were used to confirm familial relationships and assign ancestry, which was majority European (n = 1,964 European individuals). We generated polygenic scores (PGS) for ASD, IQ, chronotype and height in the subset of Europeans, and in 3,490 unrelated ancestry-matched participants from the UK Biobank. We tested for group differences for each PGS, and performed prediction analyses for related phenotypes in the AAB. We called copy-number variants (CNVs) in all participants, and intersected these with high-confidence ASD- and intellectual disability (ID)-associated CNVs and genes from the public domain. RESULTS: The ASD (p = 6.1e-13), sibling (p = 4.9e-3) and unrelated (p = 3.0e-3) groups had significantly higher ASD PGS than UK Biobank controls, whereas this was not the case for height-a control trait. The IQ PGS was a significant predictor of measured IQ in undiagnosed children (r = 0.24, p = 2.1e-3) and parents (r = 0.17, p = 8.0e-7; 4.0% of variance), but not the ASD group. Chronotype PGS predicted sleep disturbances within the ASD group (r = 0.13, p = 1.9e-3; 1.3% of variance). In the CNV analysis, we identified 13 individuals with CNVs overlapping ASD/ID-associated CNVs, and 12 with CNVs overlapping ASD/ID/developmental delay-associated genes identified on the basis of de novo variants. LIMITATIONS: This dataset is modest in size, and the publicly-available genome-wide-association-study (GWAS) summary statistics used to calculate PGS for ASD and other traits are relatively underpowered. CONCLUSIONS: We report on common genetic variation and rare CNVs within the AAB. Prediction analyses using currently available GWAS summary statistics are largely consistent with expected relationships based on published studies. As the size of publicly-available GWAS summary statistics grows, the phenotypic depth of the AAB dataset will provide many opportunities for analyses of autism profiles and co-occurring conditions, including when integrated with other omics datasets generated from AAB biospecimens (blood, urine, stool, hair).

Emerging Therapies and challenges for individuals with Angelman syndrome.

PURPOSE OF REVIEW: This review describes current understandings in the search for therapies to support children with Angelman syndrome. There is a rapid progression in particular in genetic therapies in this disorder supported by the Angelman community. RECENT FINDINGS: Recent papers shed light on the timing of therapies and novel genetic therapies coming to trial as well as potential therapies still in preclinical phases. Further understanding of UBE3A and its role in neuronal development and plasticity as well as other mechanisms contributing to the Angelman phenotype is offering an opportunity for novel therapeutics. SUMMARY: Greater understanding of the pathophysiology of the different phenotypes will offer an opportunity for novel therapeutics and may well change the course of this disorder over time where previously there has been minimal ability to intervene.

Whole genome investigation of an atypical autism case identifies a novel ANOS1 mutation with subsequent diagnosis of Kallmann syndrome.

We report an actionable secondary finding from whole-genome sequencing (WGS) of a 10-year-old boy with autism. WGS identified non-synonymous variants in several genes, including a nonsense mutation in the ANOS1 gene which is an X-linked cause of Kallmann syndrome. WGS can provide insights into complex genetic disorders such as autism, and actionable incidental findings can offer the potential for therapeutic interventions.

A systematic review of the effectiveness of sleep hygiene in children with ADHD.

Attention deficit/hyperactivity disorder (ADHD) is often accompanied by sleep problems in children. Sleep hygiene is defined as a set of behavioural, environmental, or cognitive modifications to improve sleep, and is routinely clinically utilised as first-line treatment for insomnia in ADHD. The objective of this systematic review of the literature is to evaluate the effectiveness of sleep hygiene interventions for sleep difficulties in children with ADHD. Sixteen relevant articles met the inclusion criteria, involving 1,469 participants, with a mean age of 9.6 years, across 6 countries. Fifteen studies found that sleep hygiene interventions were effective in improving sleep, while one did not show any significant improvement. Definite conclusions on the effectiveness of the interventions are difficult to draw due to the limited number of studies and a high risk of bias. There is growing evidence to support the use of sleep hygiene interventions to improve sleep quality in children with ADHD and sleep disturbance. However, well-conducted clinical trials are required to strengthen the evidence.

Associations Between Sleep Hygiene and Sleep Problems in Adolescents With ADHD: A Cross-Sectional Study.

Objective: To determine whether self-reported sleep hygiene practices are associated with self- and parent-reported behavioral sleep problems in adolescents with ADHD. Method: Participants included 79 adolescents with ADHD (13-17 years) and their parents. Adolescents were asked to report on their sleep hygiene (Adolescent Sleep Hygiene Scale) and sleep (Adolescent Sleep Wake Scale). Parents also reported on their adolescent's sleep (Sleep Disturbance Scale for Children). Results: Poorer sleep hygiene was associated with higher total self-reported behavioral sleep problems and most self-reported sleep problems: falling asleep, reinitiating sleep, and returning to wakefulness. The association was also apparent for total parent-reported behavioral sleep problems, problems with initiating and maintaining sleep, and excessive somnolence. Conclusion: This study demonstrates small-to-moderate relationships between poor sleep hygiene practices and sleep problems in adolescents with ADHD, by both self- and parent-report.

Exploring the Sensory Profiles of Children on the Autism Spectrum Using the Short Sensory Profile-2 (SSP-2).

The aim of this study was to identify sensory subtypes in children on the autism spectrum using the Short Sensory Profile-2 (SSP-2). Caregivers of children on the autism spectrum aged 4-11 years (n = 271) completed the SSP-2. Analysis using Dirichlet process mixture model identified a two-cluster model which provided the best solution to subtype sensory responses. Two distinct subtypes were identified: Uniformly elevated (67%) with high scores across all quadrants and Raised avoiding and sensitivity (33%) with raised scores in the avoiding and sensitivity quadrants. There were no differences between subtypes based on chronological age and autism characteristics measured using the social communication questionnaire (total score). Based on the SSP-2, children were reported to experience differences in responses to sensory input, in particular in the area of sensitivity and avoiding.

A case-control genome-wide association study of ADHD discovers a novel association with the tenascin R (TNR) gene.

It is well-established that there is a strong genetic contribution to the aetiology of attention deficit hyperactivity disorder (ADHD). Here, we employed a hypothesis-free genome-wide association study (GWAS) design in a sample of 480 clinical childhood ADHD cases and 1208 controls to search for novel genetic risk loci for ADHD. DNA was genotyped using Illumina's Human Infinium PsychArray-24v1.2., and the data were subsequently imputed to the 1000 Genomes reference panel. Rigorous quality control and pruning of genotypes at both individual subject and single nucleotide polymorphism (SNP) levels was performed. Polygenic risk score (PGRS) analysis revealed that ADHD case-control status was explained by genetic risk for ADHD, but no other major psychiatric disorders. Logistic regression analysis was performed genome-wide to test the association between SNPs and ADHD case-control status. We observed a genome-wide significant association (p = 3.15E-08) between ADHD and rs6686722, mapped to the Tenascin R (TNR) gene. Members of this gene family are extracellular matrix glycoproteins that play a role in neural cell adhesion and neurite outgrowth. Suggestive evidence of associations with ADHD was observed for an additional 111 SNPs (⩽9.91E-05). Although intriguing, the association between DNA variation in the TNR gene and ADHD should be viewed as preliminary given the small sample size of this discovery dataset.

Sleep in children with neurodevelopmental difficulties.

Sleep disorders in children with neurodevelopmental disorders are complex and reflect underlying genetic/biological and behavioural components. The sleep disorders are the same as in the typically developing child, although there may be some modifications to the presentation or the frequency depending on the phenotype. Consideration of the known phenotypes and environmental issues are important in defining management strategies. Despite this complexity, defined behavioural strategies with good sleep hygiene can have a significant effect on the sleep problem and on parental management of the behaviours.

Paediatric palliative care and intellectual disability-A unique context.

BACKGROUND: Paediatric palliative care is a nuanced area of practice with additional complexities in the context of intellectual disability. There is currently minimal research to guide clinicians working in this challenging area of care. METHOD: This study describes the complex care of children with life-limiting conditions and intellectual disability by means of a literature synthesis and commentary with "best-practice" guide. RESULTS: As few articles concerning children with intellectual disability and palliative care needs were identified by formal systematic review, our expert consensus group has drawn from the paediatric palliative, oncology and adult intellectual disability literature to highlight common clinical challenges encountered in the day-to-day care of children with intellectual disability and life-limiting conditions. CONCLUSION: A longitudinal child- and family-centred approach is key to ensuring best-practice care for families of children with life-limiting conditions and intellectual disability. As highlighted by the great absence of literature addressing this important patient population, further research in this area is urgently required.

Management of sleep disorders in neurodevelopmental disorders and genetic syndromes.

PURPOSE OF REVIEW: Sleep disorders in individuals with developmental difficulties continue to be a significant challenge for families, carers, and therapists with a major impact on individuals and carers alike. This review is designed to update the reader on recent developments in this area. RECENT FINDINGS: A systematic search identified a variety of studies illustrating advances in the regulation of circadian rhythm and sleep disturbance in neurodevelopmental disorders. Specific advances are likely to lead in some disorders to targeted therapies. There is strong evidence that behavioural and sleep hygiene measures should be first line therapy; however, studies are still limited in this area. Nonpharmacological measures such as exercise, sensory interventions, and behavioural are reported. Behavioural regulation and sleep hygiene demonstrate the best evidence for improved sleep parameters in individuals with neurodisability. SUMMARY: Although the mainstay of management of children with sleep problems and neurodevelopmental disability is similar to that of typically developing children, there is emerging evidence of behavioural strategies being successful in large-scale trials and the promise of more targeted therapies for more specific resistant disorders.

An open-label pilot trial of minocycline in children as a treatment for Angelman syndrome.

BACKGROUND: Minocycline, a member of the tetracycline family, has a low risk of adverse effects and an ability to improve behavioral performance in humans with cognitive disruption. We performed a single-arm open-label trial in which 25 children diagnosed with Angelman syndrome (AS) were administered minocycline to assess the safety and tolerability of minocycline in this patient population and determine the drug's effect on the cognitive and behavioral manifestations of the disorder. METHODS: Participants, age 4-12 years old, were randomly selected from a pool of previously screened children for participation in this study. Each child received 3 milligrams of minocycline per kilogram of body weight per day for 8 weeks. Participants were assessed during 3 study visits: baseline, after 8-weeks of minocycline treatment and after an 8-week wash out period. The primary outcome measure was the Bayley Scales of Infant and Toddler Development 3rd Edition (BSID-III). Secondary outcome measures included the Clinical Global Impressions Scale (CGI), Vineland Adaptive Behavior Scales 2nd Edition (VABS-II), Preschool Language Scale 4th Edition (PLS-IV) and EEG scores. Observations were considered statistically significant if p < 0.05 using ANOVA and partial eta squared (η(2)) was calculated to show effect size. Multiple comparisons testing between time points were carried out using Dunnett's post hoc testing. RESULTS: Significant improvement in the mean raw scores of the BSID-III subdomains communication and fine motor ability as well as the subdomains auditory comprehension and total language ability of the PLS-IV when baseline scores were compared to scores after the washout period. Further, improvements were observed in the receptive communication subdomain of the VABS-II after treatment with minocycline. Finally, mean scores of the BSID-III self-direction subdomain and CGI scale score were significantly improved both after minocycline treatment and after the wash out period. CONCLUSION: The clinical and neuropsychological measures suggest minocycline was well tolerated and causes improvements in the adaptive behaviors of this sample of children with Angelman syndrome. While the optimal dosage and the effects of long-term use still need to be determined, these findings suggest further investigation into the effect minocycline has on patients with Angelman syndrome is warranted. TRIAL REGISTRATION: NCT01531582 - clinicaltrials.gov.

Monitoring salivary melatonin concentrations in children with sleep disorders using liquid chromatography-tandem mass spectrometry.

BACKGROUND: Melatonin is synthesized in the pineal gland and is an important circadian phase marker, especially in the determination of sleep patterns. Both temporary and permanent abnormal sleep patterns occur in children; therefore, it is desirable to have methods for monitoring melatonin in biological fluids in the diagnosis and treatment of such disorders. OBJECTIVE: The objective of the study is to develop a liquid chromatography-tandem mass spectrometry method for the determination of melatonin in saliva and to apply it to monitoring salivary concentrations in children with sleep disorders. METHODS: A deuterated internal standard (d7-melatonin) was added to a diluted saliva sample (20 µL) in an autosampler vial insert, and 50 µL were injected. Plasticware was strictly avoided, and all glassware was scrupulously cleaned and then baked at 120°C for at least 48 hours to obtain satisfactory performance. Reverse-phase chromatography was performed on a C8 column using a linear gradient elution profile comprising mobile phases A (0.1% aqueous formic acid) and B (15% methanol in acetonitrile containing 0.1% formic acid), pumped at a total flow rate of 0.8 mL/min. The run time was 8 minutes. After atmospheric pressure chemical ionization, mass spectrometric detection was in positive ion mode. Mass detection was by selected reaction monitoring mode with the following mass transitions used for quantification: melatonin, m/z 233.0 → 173.8 and d7-melatonin, m/z 240.0 → 178.3. RESULTS: Linearity (r > 0.999) was established from 3.9 to 1000 pg/mL. Imprecision (coefficient of variation percent) was less than 11%, and accuracy was 100-105% (7.0-900 pg/mL). The method was selective, and the mean (range) ratio of the slopes of calibrations in water to those in daytime saliva samples collected from 10 healthy adult subjects was 0.989 (0.982-0.997), indicating negligible matrix effects. The application of the assay was demonstrated in healthy adults and in children being clinically investigated for sleep disturbances. CONCLUSIONS: A validated liquid chromatography-tandem mass spectrometry method suitable for monitoring salivary melatonin in children with circadian rhythm sleep disorders is reported. The method also has potential application to pediatric population pharmacokinetic studies using sparse sampling of saliva as the biological sample matrix.

A high density linkage disequilibrium mapping in 14 noradrenergic genes: evidence of association between SLC6A2, ADRA1B and ADHD.

Pharmacological evidence suggests the importance of noradrenergic and other monoaminergic neurotransmitters in the aetiology and treatment of attention deficit hyperactivity disorder (ADHD). Until recently, the genes of the noradrenergic pathway were not intensively investigated in ADHD compared to dopaminergic and serotonergic candidates. In this study, 91 SNP markers of 14 noradrenergic genes (an average density of one SNP per 4.5 kbp) were examined in ADHD samples from Ireland and Australia. Although suggestive evidence of association (nominal p ≤ 0.05) with the genes SLC6A2, ADRA1A, ADRA1B and ADRA2B was observed, none remained significant after permutation adjustments. In contrast, haplotype analyses demonstrated a significant association between ADHD and a SLC6A2 haplotype comprising the markers rs36009, rs1800887, rs8049681, rs2242447 and rs9930182 (χ(2) = 9.39, p-corrected = 0.019, OR = 1.51). A rare ADRA1B haplotype made of six SNPs (rs2030373, rs6884105, rs756275, rs6892282, rs6888306 and rs13162302) was also associated (χ(2) = 7.79, p-corrected = 0.042 OR = 2.74) with the disorder. These findings provide evidence of a contribution of the noradrenaline system to the genetic aetiology of ADHD. The observed haplotype association signals may be driven by as yet unidentified functional risk variants in or around the associated regions. Functional genomic analysis is warranted to determine the biological mechanism of the observed association.

Plasma and urinary sulfate determination in a cohort with autism.

Sulfate is important for mammalian development but is not routinely measured in clinical settings. The renal NaS1 sulfate transporter maintains circulating sulfate levels and is linked to renal sulfate wasting in mice. Some autistic individuals exhibit renal sulfate wasting, but the etiology is yet unknown. We measured plasma and urinary sulfate levels, calculated the fractional excretion index (FEI) of sulfate, and screened for two loss-of-function NaS1 sequence variants (R12X and N174S) in 23 autistic individuals. The FEI sulfate values ranged from 0.13 to 0.50. NaS1 variants were detected in 18 of the 23 individuals (11 heterozygous N174S, four homozygous N174S, two heterozygous R12X, and one individual carried both R12X and N174S). Those individuals with neither sequence variant had FEI sulfate ≤ 0.34, whereas FEI sulfate ≥ 0.35 was found in about 60 % (11 of 18) of individuals that had R12X and/or N174S. This study links renal sulfate wasting with loss-of-function NaS1 sequence variants in humans.

Sleep disturbances in CHARGE syndrome: types and relationships with behavior and caregiver well-being.

Children with CHARGE syndrome frequently develop moderate to severe behavior difficulties and are often diagnosed with obsessive-compulsive disorder, attention deficit disorder, Tourette syndrome, and autism. Anecdotal reports have indicated that sleep is also affected. However, the prevalence and types of sleep disturbance have not been identified. This study investigated sleep disturbances in 87 children with CHARGE syndrome, aged 6 to 18 years (mean 11y, SD 3y 8mo). There were 52 males and 35 females represented. Instruments included measures of sleep (Sleep Disturbances Scale for Children [SDSC]), behavior (Developmental Behaviour Checklist [DBC]), and carer well-being (Malaise Inventory). On the SDSC, 57.5% received scores considered significant for sleep disturbances, with disorders of initiating and maintaining sleep, sleep breathing, and sleep-wake transition being the most common. The SDSC was significantly correlated with the DBC (p=0.010) and the Malaise Inventory (p=0.003). Regression analysis found that both problem behavior and sleep disturbances contributed to the prediction of scores on the Malaise Inventory. Being both deaf and blind (p=0.001), experiencing frequent middle-ear infections (p=0.015), and starting to walk at an older age (p=0.007) were associated with more sleep disturbance. Craniofacial anomalies were not. The study highlights the importance of addressing the sleep difficulties associated with CHARGE syndrome relating both to airway management and to disorders of initiating sleep.

9. Common causes of sleep disruption and daytime sleepiness: childhood sleep disorders II.

There are strong associations between childhood sleep disorders and behavioural, concentration and mood problems. Sleep disorders caused and maintained by behavioural factors (eg, sleep-onset association disorder) are common in young children, and have a significant impact on families. Evaluation should include a medical history, a physical, neurological and developmental examination, a description of any nocturnal events or daytime effects of the child's disturbed sleep, and a good understanding of the family situation and parental management of the child. Management involves recognising the developmental age of the child and the family dynamics, and educating and supporting families in applying behavioural techniques to establish good sleep hygiene. Children with parasomnias (eg, night terrors) also benefit from good sleep hygiene, while those with respiratory or neurological causes of sleep disturbance should be referred for specialist treatment.