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Blood-based DNA methylation markers for autism spectrum disorder identification using machine learning.

BACKGROUND: Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder lacking objective biomarkers for early diagnosis. DNA methylation is a promising epigenetic marker, and machine learning offers a data-driven classification approach. However, few studies have examined whole-blood, genome-wide DNA methylation profiles for ASD diagnosis in school-aged children. METHODS: We analyzed genome-wide DNA methylation data from GEO dataset GSE113967, including 52 children with ASD and 48 typically developing (TD) controls. Differentially methylated positions (DMPs) were identified, and feature selection was performed using support vector machine-recursive feature elimination with cross-validation (SVM-RFECV). Classification models were developed using random forest (RF), extreme gradient boosting (XGBoost), and decision tree (DT) classifiers. A nomogram visualized feature contributions. RESULTS: A total of 138 DMPs differentiated ASD from TD children. Eleven CpG sites selected by SVM-RFECV formed the basis for model construction. RF and XGBoost achieved the highest accuracy (75%), with DT reaching 70%. Functional annotation indicated enrichment in cell adhesion and immune-related pathways. CONCLUSIONS: This exploratory study demonstrates the feasibility of integrating peripheral blood DNA methylation data with machine learning to distinguish children with ASD. While limited by sample size and moderate accuracy, this study provides methodological insights into the feasibility of integrating epigenetic and computational approaches for ASD-related biomarker exploration.

Humans↗

Transcranial Alternating Current Stimulation at 40 Hz Improves Social Functioning in Children With Autism Spectrum Disorder: A Randomized Clinical Trial.

BACKGROUND: Autism spectrum disorder (ASD) lacks rapid and effective interventions for its core social difficulties. The right temporoparietal junction (rTPJ), a critical hub for social cognition, together with gamma band abnormalities implicated in ASD, provides a promising neuromodulation target. METHODS: In this randomized, double-blind, sham-controlled trial, 47 children with ASD (39 male; mean [SD] age = 8.79 [2.71] years) were assigned to receive either 21 sessions of 40-Hz high-definition transcranial alternating current stimulation (tACS) targeting the rTPJ (3 sessions/day for 7 days) or sham stimulation, with assessments conducted at baseline, postintervention (week 1), and a 3-week follow-up (week 4). The primary outcome was change in Ohio State University Autism Rating Scale-DSM-5 (OARS-5) total scores. Secondary outcomes included the Aberrant Behavior Checklist-Second Edition, Social Responsiveness Scale-Second Edition, and Short Sensory Profile. Eye-tracking metrics during Frith-Happ&#xe9; animations were exploratory measures of theory of mind (ToM)-related social cognitive processing. RESULTS: The active group demonstrated significant improvements in OARS-5 total scores at week 1 (mean difference = -1.13, 95% CI [-1.78 to -0.47], p < .001) and week 4 (mean difference = -1.47, 95% CI [-2.20 to -0.74], p < .001). Improvements in selected behavioral and sensory domains were observed. Average fixation duration during ToM animations showed a significant group &#xd7; time interaction. No serious adverse events occurred. CONCLUSIONS: These findings suggest that 40-Hz tACS targeting the rTPJ may be associated with rapid improvements in ASD symptom severity, particularly social functioning, in children with ASD, while being well tolerated. Clinical significance requires further evaluation.

Humans↗

Autism spectrum disorders: emerging pharmacotherapy.

Autism, Asperger and other pervasive developmental disorders (PDDs) are an increasingly commonly identified group of conditions wherein patients experience significant difficulty in social interactions, communicating with others, and inflexible adherence to unusual, unhelpful and frequently stereotyped routines and behaviour. These autism spectrum disorders are now being diagnosed earlier in life (approximately 15 months), and often remain a chronic, daily burden for those afflicted. In addition to the often profound impact on an individual's quality of life, the familial, social and economic burdens of PDDs can be enormous. No treatments are curative, and most pharmacological treatments are employed to treat specific troubling symptoms rather than the core features of the disorder itself. Therefore, more effective pharmacotherapies are desperately needed. This review describes current and emerging pharmacotherapies that may advance care of people with PDDs.

Autistic Disorder↗

Cytogenetic abnormalities and fragile-X syndrome in Autism Spectrum Disorder.

BACKGROUND: Autism is a behavioral disorder with impaired social interaction, communication, and repetitive and stereotypic behaviors. About 5-10 % of individuals with autism have 'secondary' autism in which an environmental agent, chromosome abnormality, or single gene disorder can be identified. Ninety percent have idiopathic autism and a major gene has not yet been identified. We have assessed the incidence of chromosome abnormalities and Fragile X syndrome in a population of autistic patients referred to our laboratory. METHODS: Data was analyzed from 433 patients with autistic traits tested using chromosome analysis and/or fluorescence in situ hybridization (FISH) and/or molecular testing for fragile X syndrome by Southern and PCR methods. RESULTS: The median age was 4 years. Sex ratio was 4.5 males to 1 female [354:79]. A chromosome (cs) abnormality was found in 14/421 [3.33 %] cases. The aberrations were: 4/14 [28%] supernumerary markers; 4/14 [28%] deletions; 1/14 [7%] duplication; 3/14 [21%] inversions; 2/14 [14%] translocations. FISH was performed on 23 cases for reasons other than to characterize a previously identified cytogenetic abnormality. All 23 cases were negative. Fragile-X testing by Southern blots and PCR analysis found 7/316 [2.2 %] with an abnormal result. The mutations detected were: a full mutation (fM) and abnormal methylation in 3 [43 %], mosaic mutations with partial methylation of variable clinical significance in 3 [43%] and a permutation carrier [14%]. The frequency of chromosome and fragile-X abnormalities appears to be within the range in reported surveys (cs 4.8-1.7%, FRAX 2-4%). Limitations of our retrospective study include paucity of behavioral diagnostic information, and a specific clinical criterion for testing. CONCLUSIONS: Twenty-eight percent of chromosome abnormalities detected in our study were subtle; therefore a high resolution cytogenetic study with a scrutiny of 15q11.2q13, 2q37 and Xp23.3 region should be standard practice when the indication is autism. The higher incidence of mosaic fragile-X mutations with partial methylation compared to FRAXA positive population [50% vs 15-40%] suggests that faint bands and variations in the Southern band pattern may occur in autistic patients.

Autistic Disorder↗

Limbic circuitry in patients with autism spectrum disorders studied with positron emission tomography and magnetic resonance imaging.

OBJECTIVE: Cytoarchitectonic changes in the anterior cingulate cortex, hippocampus, subiculum, entorhinal cortex, amygdala, mammillary bodies, and septum were reported in a postmortem study of autism. Previously, the authors found smaller cingulate volume and decreased metabolism of the cingulate in seven autistic patients. In this study, they measured the volume and glucose metabolism of the amygdala, hippocampus, and cingulate gyrus in an expanded group of 17 patients with autism spectrum disorders (autism [N=10] or Asperger's disorder [N=7]) and 17 age- and sex-matched healthy volunteers. METHOD: Subjects performed a serial verbal learning test during (18)F-deoxyglucose uptake. The amygdala, hippocampus, and cingulate gyrus were outlined on magnetic resonance imaging scans, volumes of the structures were applied to matching coregistered positron emission tomography scans, and three-dimensional significance probability mapping was performed. RESULTS: Significant metabolic reductions in both the anterior and posterior cingulate gyri were visualized in the patients with autism spectrum disorders. Both Asperger's and autism patients had relative glucose hypometabolism in the anterior and posterior cingulate as confirmed by analysis of variance; regional differences were also found with three-dimensional significance probability mapping. No group differences were found in either the metabolism or the volume of the amygdala or the hippocampus. However, patients with autism spectrum disorders showed reduced volume of the right anterior cingulate gyrus, specifically in Brodmann's area 24'. CONCLUSIONS: Compared with age- and sex-matched healthy volunteers, patients with autism spectrum disorders showed significantly decreased metabolism in both the anterior and posterior cingulate gyri.

Adult↗

The effect of semantic and emotional context on written recall for verbal language in high functioning adults with autism spectrum disorder.

OBJECTIVE: Several deficits have been proposed to account for cognitive impairment in autism including an inability to comprehend the perspectives of others ("theory of mind"), an inability to process emotional information, and difficulty drawing together diverse information in context ("central coherence"). Because context (central coherence) and emotion can influence memory, a study was designed to show if autism spectrum disorder was associated with impaired utilisation of context and emotion in recall; and if impairments in theory of mind processing would influence recall in autism spectrum disorder. METHODS: Ten high functioning subjects with autism spectrum disorder and 13 age and IQ matched controls were tested using recall tests. In the first coherence memory test, subjects listened to a series of word lists that were in varying degrees of syntactic and semantic (coherent) order and were asked to recall the words. In the second coherence memory test, subjects listened to stories consisting of sentences that were, or were not, in logical (coherent) order. In the emotional memory test, the subjects listened to sentences that were highly emotional or non-emotional. In the theory of mind test, the subjects listened to stories requiring varying levels of understanding of the perspectives of others. RESULTS: There were no significant differences between groups in recall of coherent versus incoherent word lists, nor was there a significant difference between groups in recall of coherent versus incoherent stories. However, the control subjects recalled more of the emotional than non-emotional sentences, whereas the autism spectrum disorder group did not show such a difference. No significant difference existed in recall of stories requiring varying levels of understanding of the perspectives of others among subjects with autism spectrum disorder, and subjects with autism spectrum disorder did not differ from control subjects in the influence of theory of mind content on story recall. CONCLUSION: The study shows that memory in high functioning adults with autism spectrum disorder is facilitated by emotional content to a lesser degree than it is facilitated by coherence. Therefore, impairments in emotional processing cannot be considered as simply an effect of the "weak central coherence" theory in autism spectrum disorder. Whereas the reasons for this emotional deficit are unknown, evidence of abnormalities of the limbic structures in autism spectrum disorder may provide an anatomical explanation.

Adult↗

[Large-scale genotyping in research into autism spectrum disorders and attention deficit hyperactivity disorder].

INTRODUCTION AND DEVELOPMENT: Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are two neuropsychiatric disorders beginning in childhood that present a high degree of familial aggregation. ASD is characterised by social interaction and communication disorders, whereas patients with ADHD display persistent inattention and/or hyperactive-impulsive behaviour. With the exception of a few cases of autism in which cytogenetic anomalies or mutations have been reported in specific genes, the aetiology of these diseases remains unknown. This is a group of multifactorial diseases with several genes having a lesser effect and there is also an environmental component. Genetic linkage studies have pointed to about 20 chromosomal regions that could well contain genes that grant susceptibility to autism, to ADHD or to both disorders. The challenge to researchers lies in the clinical characterisation, recruitment of patients with ASD and ADHD, gene dosage quantification studies, comparative genomic methylation and hybridisation in order to identify chromosomal rearrangements in patients with autism and severe mental retardation. CONCLUSIONS: Genotyping large SNP-type collections that are potentially functional in genes that are candidates for these disorders, based on pharmacological, biochemical and neuropathological data together with that coming from animal models and linkage studies in a wide collection of samples from patients and controls, will enable us to identify the genetic components of these pathologies and to define their biological foundations.

Attention Deficit Disorder with Hyperactivity↗

Bipolar disorder, schizophrenia, and other psychotic disorders in adults with childhood onset AD/HD and/or autism spectrum disorders.

Individuals with attention-deficit/hyperactivity disorder (AD/HD) and autism spectrum disorders (ASD) often display symptoms from other diagnostic categories. Exclusion criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the International Statistical Classification of Diseases and Related Health Problems (ICD-10) impede the use of categorical diagnoses to describe the particular problem constellation in a patient. In this study, we describe the prevalence and patterns of comorbid bipolar and psychotic disorders in 241 consecutively referred adult patients with AD/HD and/or ASD. Thirty per cent of patients with AD/HD had comorbid ASD and 38% of patients with ASD had comorbid AD/HD. Of the subjects with ASD, 7% had bipolar disorder with psychotic features, and 7.8% had schizophrenia or another psychotic disorder. The corresponding figures for the patients with AD/HD were 5.0% and 5.0%, respectively. Current diagnostic criteria have to be revised to acknowledge the comorbidity of bipolar and/or psychotic disorders in AD/HD and ASD.

Adult↗

Treating anxiety disorders in children with high functioning autism spectrum disorders: a controlled trial.

A family-based, cognitive behavioural treatment for anxiety in 47 children with comorbid anxiety disorders and High Functioning Autism Spectrum Disorder (HFA) was evaluated. Treatment involved 12 weekly group sessions and was compared with a waiting list condition. Changes between pre- and post-treatment were examined using clinical interviews as well as child-, parent- and teacher-report measures. Following treatment, 71.4% of the treated participants no longer fulfilled diagnostic criteria for an anxiety disorder. Comparisons between the two conditions indicated significant reductions in anxiety symptoms as measured by self-report, parent report and teacher report. Discussion focuses on the implications for the use of cognitive behaviour therapy with HFA children, for theory of mind research and for further research on the treatment components.

Adolescent↗

A comparison of health care utilization and costs of children with and without autism spectrum disorders in a large group-model health plan.

OBJECTIVE: Data on the current costs of medical services for children with autism spectrum disorders are lacking. Our purpose for this study was to compare health care utilization and costs of children with and without autism spectrum disorders in the same health plan. PATIENTS AND METHODS: Participants included all 2- to 18-year-old children with autism spectrum disorders (n = 3053) and a random sample of children without autism spectrum disorders (n = 30529) who were continuously enrolled in the Kaiser Permanente Medical Care Program in northern California between July 1, 2003, and June 30, 2004. Data on health care utilization and costs were derived from health plan administrative databases. MAIN OUTCOME MEASURES: Outcome measures included mean annual utilization and costs of health services per child. RESULTS: Children with autism spectrum disorders had a higher annual mean number of total clinic (5.6 vs 2.8), pediatric (2.3 vs 1.6), and psychiatric (2.2 vs 0.3) outpatient visits. A higher percentage of children with autism spectrum disorders experienced inpatient (3% vs 1%) and outpatient (5% vs 2%) hospitalizations. Children with autism spectrum disorders were nearly 9 times more likely to use psychotherapeutic medications and twice as likely to use gastrointestinal agents than children without autism spectrum disorders. Mean annual member costs for hospitalizations (550 dollars vs 208 dollars), clinic visits (1373 dollars vs 540 dollars), and prescription medications (724 dollars vs 96 dollars) were more than double for children with autism spectrum disorders compared with children without autism spectrum disorders. The mean annual age- and gender-adjusted total cost per member was more than threefold higher for children with autism spectrum disorders (2757 dollars vs 892 dollars). Among the subgroup of children with other psychiatric conditions, total mean annual costs were 45% higher for children with autism spectrum disorders compared with children without autism spectrum disorders; excess costs were largely explained by the increased use of psychotherapeutic medications. CONCLUSIONS: The utilization and costs of health care are substantially higher for children with autism spectrum disorders compared with children without autism spectrum disorders. Research is needed to evaluate the impact of improvements in the management of children with autism spectrum disorders on health care utilization and costs.

Adolescent↗

Chromosome 15q11-13 abnormalities and other medical conditions in individuals with autism spectrum disorders.

OBJECTIVES: The frequency of abnormalities of 15q11-q13 and other possibly causal medical disorders including karyotypic abnormalities was investigated in an unselected series of children who were referred to one of two autism assessment centres. METHODS: Two hundred and twenty-one cases were assessed using the Autism Diagnostic Interview and Observation Schedule and, where appropriate, standardized tests of intelligence and language abilities. Medical histories and notes were reviewed, and molecular and cytogenetic investigations used to detect chromosomal abnormalities. RESULTS: One hundred and eighty-one cases were diagnosed according to International Classification of Diseases - version 10 criteria as having an autism spectrum disorder (autistic-like Pervasive Developmental Disorder) and 40 cases as having other disorders. Twenty-one (11.6%) of the children with autism spectrum disorders had a possibly causal condition compared with six (15%) of the children with other diagnoses. One child with an autism spectrum disorder had a paternally inherited familial duplication of 15q11-13. The pattern of genotype-phenotype correlation within the family indicated that this form of abnormality might carry a risk for developmental difficulties, although the risk did not appear to be specific for autism spectrum disorders. CONCLUSION: The overall rate of possibly causal medical and cytogenetic conditions in children with autism spectrum disorders was low and no different from the rate of disorder in children with other developmental/neuropsychiatric disorders that attended the same clinics. Further research is required to determine whether paternal duplication of 15q11-13 gives rise to adverse developmental outcomes.

Autistic Disorder↗

Safety issues with drug therapies for autism spectrum disorders.

Although currently no medication has been approved to treat autism spectrum disorders, survey data show that community practitioners are prescribing a broad range of medication treatments, including, but not limited to, antidepressants, stimulants, antipsychotics, alpha agonists, and anticonvulsants. Patients with autism spectrum disorders are also taking alternative treatments, including herbal remedies, immunologic treatments, and vitamin therapies, which may themselves produce side effects and/or create drug interactions with traditional medications. Although short-term data on the efficacy and safety of commonly prescribed treatments for autism spectrum disorders are increasing, few data are currently available on long-term treatment for autism spectrum disorders, but available studies and clinical experience can offer preliminary recommendations on the safety of and monitoring needs for the medications currently used for these disorders. Monitoring the safety and tolerability of drugs used in patients with these disorders should minimize the burden of side effects and optimize treatment outcome.

Adolescent↗

Neuro-epileptic determinants of autism spectrum disorders in tuberous sclerosis complex.

Tuberous sclerosis is one of the few established medical causes of autism spectrum disorder and is a unique neurogenetic model for testing theories about the brain basis of the syndrome. We conducted a retrospective case study of the neuro-epileptic risk factors predisposing to autism spectrum disorder in individuals with tuberous sclerosis to test current neurobiological theories of autism spectrum disorder. We found that an autism spectrum disorder diagnosis was associated with the presence of cortical tubers in the temporal but not other lobes of the brain. Indeed, the presence of tubers in the temporal lobes appeared to be a necessary but not sufficient risk factor for the development of an autism spectrum disorder. However, contrary to the predictions of some theories, the location of tubers in specific regions of the temporal lobe, such as the superior temporal gyrus or the right temporal lobe, did not determine which individuals with temporal lobe tubers developed an autism spectrum disorder. Instead, outcome was associated with various indices of epileptic activity including evidence of temporal lobe epileptiform discharges on EEG, the age to onset of seizures in the first 3 years of life and a history of infantile spasms. The results indicated that individuals with tuberous sclerosis are at very high risk of developing an autism spectrum disorder when temporal lobe tubers are present and associated with temporal lobe epileptiform discharges and early-onset, persistent spasm-like seizures. These risk markers constitute useful clinical indicators of prognosis, but further research is required to identify the neurobiological mechanisms responsible for their association with outcome. Most especially, it will be important to test whether, as the findings suggest, there is a critical early stage of brain maturation during which temporal lobe epilepsy perturbs the development of brain systems that underpin 'social intelligence' and possibly other cognitive skills, thereby inducing an autism spectrum disorder.

Autistic Disorder↗

Interhemispheric transfer in high-functioning children and adolescents with autism spectrum disorders: a controlled pilot study.

Autism is a neurodevelopmental disorder with strong genetic influences. Clinical experience and limited empirical evidence support the view that autism may be associated with aberrant interhemispheric information transfer. This empirical controlled study examined whether, at neuropsychological testing, children with autism showed problems with interhemispheric information transfer. The study included auditory, visual, and motor measures covering information transfer within, as well as across, modalities. Thirty children (24 males, 6 females; mean age 12 years 8 months, SD 2 years 8 months; range 9 years 5 months to 17 years 5 months) without learning disability but with autism spectrum disorders were compared with 30 children from a mainstream school matched for age, sex, and IQ>75. Children with autism spectrum disorder performed significantly worse than the comparison group on most of the tests (p=0.02 for auditory perception and attention, p=0.005 for visual perception, p=0.0001 for motor control, p=0.04 for tactile perception). Results support the notion that aberrant interhemispheric transfer may be involved in the pathogenesis or clinical course of autism. The findings were not accounted for by lower IQ in the group with autism.

Adolescent↗

Metabolic approaches to the treatment of autism spectrum disorders.

Although the exact prevalence of metabolic abnormalities in autism spectrum disorders is unknown, several metabolic defects have been associated with autistic symptoms. These include phenylketonuria, histidinemia, adenylosuccinate lyase deficiency, dihydropyrimidine dehydrogenase deficiency, 5'-nucleotidase superactivity, and phosphoribosylpyrophosphate synthetase deficiency. When the metabolic consequences of an enzyme defect are well defined (e.g., phenylketonuria, 5'-nucleotidase superactivity), treatment with diet, drugs, or nutritional supplements may bring about a dramatic reduction in autistic symptoms. This review evaluates evidence for metabolic etiologies in autism spectrum disorders, as well as for the efficacy of dietary and vitamin treatments. The relationship between gastrointestinal abnormalities and autism spectrum disorders is also considered.

Autistic Disorder↗

Domains of social communication handicap in autism spectrum disorder.

OBJECTIVE: To investigate whether specific "social communication" handicaps could be identified in autism spectrum disorder using the Autism Diagnostic Observation Schedule and to compare the results with those found in a previous factor-analysis study using the Autism Diagnostic Interview-Revised. METHOD: All subjects were evaluated with both instruments. J.R. and P.E.T. independently diagnosed autism, Asperger's disorder, or pervasive developmental disorder--not otherwise specified in 51 children. Items from the Autism Diagnostic Observation Schedule that represented social communication behaviors were factor-analyzed. RESULTS: Three factors were identified: joint attention, affective reciprocity, and theory of mind. These are the same social communication domains that were identified in the previous study. CONCLUSIONS: These 3 social communication domains have been discussed in the literature regarding normal development and in previous research on autism spectrum disorders. If these domains are replicated in larger sample sizes, they could be used to monitor the results of pharmacological and psychotherapeutic interventions in autism spectrum disorders.

Adolescent↗

Incidence of autism spectrum disorders in children in two Australian states.

AIM: To ascertain the incidence of autism spectrum disorders in Australian children. SETTING: New South Wales (NSW) and Western Australia (WA), July 1999 to December 2000. DESIGN: Data were obtained for WA from a prospective register and for NSW by active surveillance. MAIN OUTCOME MEASURES: Newly recognised cases of autism spectrum disorders (defined as autistic disorder, Asperger disorder and pervasive developmental disorder not otherwise specified [PDD-NOS]) in children aged 0-14 years; incidence was estimated in 5-year age bands (0-4 years, 5-9 years, 10-14 years). RESULTS: In WA, 252 children aged 0-14 years were identified with autism spectrum disorder (169 with autistic disorder and 83 with Asperger disorder or PDD-NOS). Comparable figures in NSW were 532, 400 and 132, respectively. Most children were recognised with autistic disorder before school age (median age, 4 years in WA and 3 years in NSW). Incidence of autistic disorder in the 0-4-years age group was 5.5 per 10,000 in WA (95% CI, 4.5-6.7) and 4.3 per 10,000 in NSW (95% CI, 3.8-4.8). Incidence was lower in older age groups. The ratio of all autism spectrum disorders to autistic disorder alone was 1.5:1 in WA and 1.3:1 in NSW, and rose with age (1.8:1 and 2.9:1 in 10-14-year-olds in WA and NSW, respectively). CONCLUSIONS: These are the first reported incidence rates for autism for a large Australian population and are similar to rates reported from the United Kingdom. Ongoing information gathering in WA and repeat active surveillance in NSW will help to monitor any future changes.

Adolescent↗

A comparison of central coherence skills between adolescents with an intellectual disability with and without comorbid autism spectrum disorder.

Central coherence theory hypothesizes individuals with autism process information in a detail-focused fashion. The present study examined whether adolescents with an intellectual disability and comorbid autism spectrum disorder showed a weaker central coherence than age- and IQ-matched controls. The central coherence skills of 43 adolescents from schools for students with severe learning problems were examined with two cognitive tasks. In these two tasks, detail-focused processing is beneficial to global processing to perform the tasks accurately and quickly. The group with autism spectrum disorder performed better than the control group. Adolescents with an intellectual disability and with comorbid autism spectrum disorder have a weaker central coherence than age- and IQ-matched controls. Partial support was also given for variability in weak central coherence within the autism spectrum.

Adolescent↗