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PubMed2006

Structural correlates of intellectual impairment and autistic features in adolescents.

Intellectual disability, a common but under-researched condition, is strongly associated with autism spectrum disorders (ASD). Although studies have investigated the neural correlates of intelligence quotient (IQ) and ASD in intellectually unimpaired subjects, these issues have not been addressed in intellectually impaired subjects. We studied 63 intellectually disabled adolescents receiving additional learning support and 72 controls using whole brain tissue volumes extracted from native space and voxel-based morphometry (VBM) in normalised space. We applied a qualitative and quantitative review of VBM preprocessing and modified the optimised method to establish optimum co-registration of the brains in normalised space. We report tissue density differences at cluster level with adjustment for underlying smoothness. Individuals with intellectual disability had smaller total white matter and total brain tissue volumes than controls, as well as reduced grey matter density in the right cerebellar hemisphere and left temporo-parietal cortex, and reduced white matter density in the posterior corpus callosum. Intellectually disabled subjects were additionally subgrouped according to their degree of reported autistic features. Reduced grey matter density was detected in the thalamus of subjects with autistic features scoring within the pervasive developmental disorder range as compared to subjects below the threshold for ASD, and increased white matter density was detected in the left superior temporal gyrus of subjects scoring above the threshold for autism as compared to subjects below the threshold for ASD.

Adolescent↗

PubMed2025

Complex Genetics and Regulatory Drivers of Hypermobile Ehlers-Danlos Syndrome: Insights from Genome-Wide Association Study Meta-analysis.

BACKGROUND: Hypermobile Ehlers-Danlos syndrome (hEDS) is the most common subtype of EDS, a group of heritable connective tissue disorders. Clinically, hEDS is defined by generalized joint hypermobility and chronic musculoskeletal pain, but its impact extends beyond the musculoskeletal system. Affected individuals frequently experience autonomic, gastrointestinal, immune, and neuropsychiatric involvement, highlighting both the multisystemic nature of the condition and challenges of diagnosis. In contrast to other EDS subtypes with defined genetic causes, the molecular basis of hEDS has remained elusive. METHODS: We conducted a genome-wide association study (GWAS) of hEDS across three case controls studies, including 1,815 cases and 5,008 ancestry-matched controls. Fixed-effects meta-analysis of 6.2 million variants was complemented with LDAK gene-based association testing, transcriptome-wide association studies, and integrative annotation across multiple tissues and cell types including eQTLs, enhancer marks and open chromatin accessibility profiles, supported by luciferase assays on one candidate variant. LD-score genetic correlations were assessed between hEDS and 19 frequently reported comorbid conditions. RESULTS: Two loci reached genome-wide significance, including a regulatory region near the atypical chemokine receptor 3 gene (ACKR3) on chromosome 2. Functional annotation supports ACKR3 risk alleles colocalize with eQTLs in tibial nerve, alter enhancer activity, and generate a de novo AHR transcription factor regulatory site, implicating neuroimmune and pain signaling pathways. Gene-based and transcriptome-wide analyses identified common variants in a locus containing multiple candidates, including SLC39A13, a zinc transporter critical for connective tissue development previously implicated in a rare form of EDS, and PSMC3, a gene involved in central nervous system development. LD-score regression revealed significant genetic correlations between hEDS and joint hypermobility, myalgic encephalomyelitis/chronic fatigue syndrome, fibromyalgia, depression, anxiety, autism spectrum disorder, migraine, and gastrointestinal diseases. CONCLUSIONS: These results establish the first evidence of common variant contributions to hEDS, supporting a complex, multisystem model involving neuroimmune-stromal dysregulation. Our findings add novel indications to hEDS pathogenesis and provide solid foundations for future molecular definition and therapeutic discovery.

Genome-wide association study↗

PubMed2003

Evidence of brain overgrowth in the first year of life in autism.

CONTEXT: Autism most commonly appears by 2 to 3 years of life, at which time the brain is already abnormally large. This raises the possibility that brain overgrowth begins much earlier, perhaps before the first clinically noticeable behavioral symptoms. OBJECTIVES: To determine whether pathological brain overgrowth precedes the first clinical signs of autism spectrum disorder (ASD) and whether the rate of overgrowth during the first year is related to neuroanatomical and clinical outcome in early childhood. DESIGN, SETTING, AND PARTICIPANTS: Head circumference (HC), body length, and body weight measurements during the first year were obtained from the medical records of 48 children with ASD aged 2 to 5 years who had participated in magnetic resonance imaging studies. Of these children, 15 (longitudinal group) had measurements at 4 periods during infancy: birth, 1 to 2 months, 3 to 5 months, and 6 to 14 months; and 33 (partial HC data group) had measurements at birth and 6 to 14 months (n = 7), and at birth only (n = 28). MAIN OUTCOME MEASURES: Age-related changes in infants with ASD who had multiple-age measurements, and the relationship of these changes to brain anatomy and clinical and diagnostic outcome at 2 to 5 years were evaluated by using 2 nationally recognized normative databases: cross-sectional normative data from a national survey and longitudinal data of individual growth. RESULTS: Compared with normative data of healthy infants, birth HC in infants with ASD was significantly smaller (z = -0.66, P<.001); after birth, HC increased 1.67 SDs and mean HC was at the 84th percentile by 6 to 14 months. Birth HC was related to cerebellar gray matter volume at 2 to 5 years, although the excessive increase in HC between birth and 6 to 14 months was related to greater cerebral cortex volume at 2 to 5 years. Within the ASD group, every child with autistic disorder had a greater increase in HC between birth and 6 to 14 months (mean [SD], 2.19 [0.98]) than infants with pervasive developmental disorder-not otherwise specified (0.58 [0.35]). Only 6% of the individual healthy infants in the longitudinal data showed accelerated HC growth trajectories (>2.0 SDs) from birth to 6 to 14 months; 59% of infants with autistic disorder showed these accelerated growth trajectories. CONCLUSIONS: The clinical onset of autism appears to be preceded by 2 phases of brain growth abnormality: a reduced head size at birth and a sudden and excessive increase in head size between 1 to 2 months and 6 to 14 months. Abnormally accelerated rate of growth may serve as an early warning signal of risk for autism.

Anthropometry↗

PubMed2000

Abnormal ventral temporal cortical activity during face discrimination among individuals with autism and Asperger syndrome.

BACKGROUND: Recognition of individual faces is an integral part of both interpersonal interactions and successful functioning within a social group. Therefore, it is of considerable interest that individuals with autism and related conditions have selective deficits in face recognition (sparing nonface object recognition). METHOD: We used functional magnetic resonance imaging (fMRI) to study face and subordinate-level object perception in 14 high-functioning individuals with autism or Asperger syndrome (the autism group), in comparison with 2 groups of matched normal controls (normal control group ] [NC1] and normal control group 2 [NC2]) (n = 14 for each). Regions of interest (ROIs) were defined in NC1 and then applied in comparisons between NC2 and the autism group. Regions of interest were also defined in NC2 and then applied to comparisons between NC1 and the autism group as a replication study. RESULTS: In the first set of comparisons, we found significant task x group interactions for the size of activation in the right fusiform gyrus (FG) and right inferior temporal gyri (ITG). Post hoc analyses showed that during face (but not object) discrimination, the autism group had significantly greater activation than controls in the right ITG and less activation of the right FG. The replication study showed again that the autism group used the ITG significantly more for processing faces than the control groups, but for these analyses, the effect was now on the left side. Greater ITG activation was the pattern found in both control groups during object processing. CONCLUSIONS: Individuals with autism spectrum disorders demonstrate a pattern of brain activity during face discrimination that is consistent with feature-based strategies that are more typical of nonface object perception.

Adult↗

PubMed2006

Gray and white matter brain chemistry in young children with autism.

CONTEXT: The brain pathophysiological abnormalities underlying autism remain unclear. Neuroimaging and histological studies suggest cellular abnormalities early in the course of the disease. OBJECTIVE: To measure the in vivo chemical profile of gray and white matter tissues in autism. DESIGN: Cross-sectional spectroscopic imaging study comparing 3- to 4-year-old children with autism spectrum disorder (ASD) with age-matched comparison groups of children with delayed development (DD) and typical development (TD). SETTING: The University of Washington Diagnostic Imaging Sciences Center, Seattle. PARTICIPANTS: Forty-five 3- to 4-year-old children with ASD, 12 age-matched children with DD, and 10 age-matched children with TD. MAIN OUTCOME MEASURES: Estimates of gray and white matter concentrations for choline-containing compounds (Cho), creatine plus phosphocreatine, N-acetylaspartate (NAA), and myo-inositol (mI). Transverse relaxation times for Cho, creatine plus phosphocreatine, and NAA expressed relative to control subjects with TD were examined to evaluate tissue compactness. RESULTS: The children with ASD demonstrated decreased gray matter concentrations of Cho (P < .001), creatine plus phosphocreatine (P = .02), NAA (P = .02), and mI (P = .008) compared with children with TD. Gray matter Cho transverse relaxation was also prolonged for the ASD sample compared with the TD group (P = .01). The children with ASD demonstrated significantly decreased levels of Cho (P = .04) and mI (P = .008) and trend-level NAA (P = .09) in gray matter compared with the DD group. For white matter, both children with ASD and children with DD showed a similar pattern of NAA and mI level decreases (for children with ASD vs children with TD: NAA, P = .03; mI, P = .04; for children with DD vs children with TD, NAA, P = .03; mI, P = .07). In several analyses, cerebral volume contributed significantly as a covariate. CONCLUSIONS: Reduced gray matter chemical concentrations and altered Cho transverse relaxation, in a pattern distinct from that in children with DD, suggest decreased cellularity, or density, at this early time point in ASD. Possibly reflecting shared developmental features, white matter results were common to ASD and DD groups. The relationship between cerebral volume and neurochemistry at this early time point may indicate processes related to unit scaling.

Aspartic Acid↗

PubMed2001

Angelman syndrome: mimicking conditions and phenotypes.

The diagnosis of Angelman syndrome (AS) can be confirmed by genetic laboratory in about 80% of cases. In 20%, the diagnosis remains clinical, but often there is uncertainty about the correctness of the clinical diagnosis and alternative diagnoses may be investigated. In evaluating individuals for AS in our center since 1989, we have encountered several mimicking conditions, and additional ones have been reported in the literature. Mimicking conditions can be grouped into the areas of chromosome, single gene, and symptom complex anomalies. Microdeletions or microduplications include chromosome regions 2,4,17, 22, and 15. Single gene conditions include methylene tetrahydrofolate reductase deficiency (MTHFR), Rett syndrome, alpha-thalassemia retardation syndrome (ATR-X), and Gurrieri syndrome. Symptom complexes include cerebral palsy, static encephalopathy, Lennox-Gastaut syndrome, autism spectrum disorder, pervasive developmental delay (PDD), and mitochondrial disorders. We present a review of these mimicking disorders to increase the awareness about conditions that can lead to an incorrect clinical diagnosis of AS.

Angelman Syndrome↗

PubMed2002

Social interest and the development of cortical face specialization: what autism teaches us about face processing.

Investigations of face processing in persons with an autism spectrum disorder (ASD) inform upon theories of the development of "normal" face processing, and the story that emerges challenges some models of the nature and origin of cortical face specialization. Individuals with an ASD possess deficits in face processing and a lack of a fusiform face area (FFA). Evidence from studies of ASD can be conceptualized best using an expertise framework of face processing rather than models that postulate a face module in the fusiform gyrus. Because persons with an ASD have reduced social interest, they may fail to develop cortical face specialization. Face specialization may develop in normal individuals because they are socially motivated to regard the face, and such motivation promotes expertise for faces. The amygdala is likely the key node in the system that marks objects as emotionally salient and could be crucial to the development of cortical face specialization.

Adolescent↗

PubMed2004

Identifying environmental contributions to autism: provocative clues and false leads.

The potential role of environmental factors in autism spectrum disorders (ASD) is an area of emerging interest within the public and scientific communities. The high degree of heritability of ASD suggests that environmental influences are likely to operate through their interaction with genetic susceptibility during vulnerable periods of development. Evaluation of the plausibility of specific neurotoxicants as etiological agents in ASD should be guided by toxicological principles, including dose-effect dependency and pharmacokinetic parameters. Clinical and epidemiological investigations require the use of sufficiently powered study designs with appropriate control groups and unbiased case ascertainment and exposure assessment. Although much of the existing data that have been used to implicate environmental agents in ASD are limited by methodological shortcomings, a number of efforts are underway that will allow more rigorous evaluation of the role of environmental exposures in the etiology and/or phenotypic expression of the disorder. Surveillance systems are now in place that will provide reliable prevalence estimates going forward in time. Anticipated discoveries in genetics, brain pathology, and the molecular/cellular basis of functional impairment in ASD are likely to provide new opportunities to explore environmental aspects of this disorder.

Autistic Disorder↗

PubMed2002

Temporal Lobe Resections in Children with Epilepsy: Neuropsychiatric Status in Relation to Neuropathology and Seizure Outcome.

The purpose of this work was to relate clinical neuropsychiatric findings to histopathological diagnoses and seizure outcome in a retrospective study of 16 children undergoing temporal lobe resections due to medically intractable epilepsy. These children constitute a heterogeneous group in which neuropsychiatric symptoms were common. The results of this study indicate a correlation between malformations of cortical development, less chance of seizure freedom, and neuropsychiatric problems in children with pharmacoresistant temporal lobe epilepsy. It is important to include neuropsychiatric assessments pre- and postoperatively and to inform parents that symptoms of autism spectrum disorders may or may not be improved after epilepsy surgery.

Journal Article↗

PubMed2005

Complementary and alternative medicine in developmental disabilities.

Developmental disabilities (DD) are defined as a diverse group of severe chronic conditions due to mental and/or physical impairments. Individuals with developmental disabilities have difficulty with major life activities including language, mobility, and learning. Developmental disabilities can begin anytime during development--from prenatal up to 22 years of age, and the disability usually lasts throughout a person's lifetime. Autism spectrum disorders, cerebral palsy, mental retardation, and attention deficit hyperactivity disorder are common conditions falling within the definition of developmental disabilities. Complementary and alternative medicine (CAM) is becoming increasingly utilized in the general population for treatment of everything from the common cold to complex and chronic medical conditions. This article reviews the prevalence of different types of CAM used for various developmental disabilities.

Child↗

PubMed2026

Complexity in disguise: a systematic review of fractal analysis in psychiatric neuroimaging.

OBJECTIVES: Psychiatric diagnosis and fractal studies are complex processes that extend beyond clinical evaluation and require careful methodological considerations in neuroimaging. Over the years, fractals have helped reduce these complexities in research, but they still cannot grant clinical diagnoses. Thus, the main objective was a systematic review exploring the potential applications of fractal analysis in characterizing psychiatric conditions through neuroimaging techniques-including both functional and structural MRI. MATERIALS AND METHODS: A systematic literature review was conducted on PubMed, identifying thirty-nine original studies that met the inclusion criteria. Areas showing statistical significance (p < 0.05) were reported. These studies were categorized according to DSM-V classification and examined for the description of psychiatric conditions through the fractal analysis. RESULTS: The review primarily focuses on young adults with psychiatric conditions compared to control groups. Schizophrenia and Autism Spectrum Disorder are major areas of investigation, and fractal dimension (FD) is the primary analysis method used to reflect brain patterns. Studies that calculated whole-brain FD may have underestimated local abnormalities due to the inclusion of a high percentage of tissue, potentially resulting in overlooked findings. Notably, abnormalities in the frontal cortex represent a common neurobiological feature across several psychiatric conditions. CONCLUSIONS: The findings from this systematic review shed light on the use of fractal analysis to quantify complex brain patterns in both psychiatric patients and healthy individuals. However, it is essential to recognize the need for further research to elucidate a fractal analysis protocol that allows for optimal extraction of psychiatric insights. KEY POINTS: Question Fractal analysis applied to structural and functional MRI help characterize brain alterations across psychiatric conditions. Findings This review shows consistent fractal patterns across multiple psychiatric disorders, especially in frontal regions. Despite heterogeneous methodologies, results highlight shared structural and functional abnormalities. Clinical relevance Fractal analysis may offer complementary characterization of subtle brain organization across psychiatric disorders. Its potential clinical utility-such as improving diagnostic characterization, earlier detection, among others-remains limited by the current absence of a standardized protocol.

Humans↗

PubMed2026

Beyond Rett syndrome: a case series expanding the neurological spectrum associated with pathogenic MECP2 variants.

BACKGROUND: Although pathogenic variants in MECP2 are classically associated with Rett syndrome (RTT), increasing evidence suggests that they can underlie a broader spectrum of neurological phenotypes. Clinical manifestations may vary according to sex, variant type, residual protein function, and pattern of X-chromosome inactivation. METHODS: We describe five unrelated individuals carrying pathogenic MECP2 variants identified through multiplex ligation-dependent probe amplification, chromosomal microarray analysis, and next-generation sequencing. Clinical, neuroradiological, neurophysiological, and molecular findings were retrospectively reviewed. RESULTS: Two unrelated girls carrying large de novo Xq28 deletions encompassing the entire MECP2 locus presented with mild neurodevelopmental impairment and epilepsy, but no developmental regression or classic RTT features. Both girls showed borderline cognitive functioning and normal brain MRI. A 9-year-old boy carrying a maternally inherited MECP2 frameshift variant presented with intellectual disability, autism spectrum disorder, and focal epilepsy, whereas carriers in his family exhibited milder neuropsychiatric manifestations. A 44-year-old man carrying a MECP2 missense variant presented with an early-onset spastic-ataxic syndrome, peripheral neuropathy, and cerebellar dysfunction, while a 16-year-old girl patient carrying a distinct de novo MECP2 missense variant displayed isolated mild motor incoordination and subtle cerebellar signs with preserved cognitive functioning. CONCLUSIONS: Our findings expand the evidence that pathogenic MECP2 variants can produce neurological phenotypes distinct from classic RTT, including mild neurodevelopmental impairment without regression, and predominantly cerebellar or spastic-ataxic manifestations associated with limited cognitive involvement. Allelic heterogeneity seems to correlate with clinical phenotypes, at least in our small cohort. In conjunction with established diagnostic criteria, these observations support testing MECP2 in a selection of atypical neurodevelopmental and movement disorder presentations.

Humans↗

PubMed2005

Asperger syndrome: familial and pre- and perinatal factors.

OBJECTIVE: Study familial and pre- and perinatal factors in Asperger Syndrome (AS). METHODS: One hundred boys with AS had their records reviewed. "Pathogenetic subgroups" were defined according to presence of medical syndromes/chromosomal abnormalities, indices of familiality, and pre- and perinatal risk factors predisposing to brain damage. RESULTS: No major index of pathogenetic factors was found in 13%, a syndrome/chromosomal abnormality in 8%, pre- or perinatal risk 13%, combined pre- or perinatal risk and family history in 11%, and family history only in 55%. COMMENT: About 50% of all boys with AS have a paternal family history of autism spectrum disorder. Pre- and perinatal risks appear to be important in about 25% of cases.

Adolescent↗

PubMed2005

Brief report: autism in individuals with Down syndrome.

As an off-shoot of a study examining the reliability and validity of an adapted version of the Pre-Linguistic Autism Diagnostic Observation Schedule (A-PL-ADOS), 13 individuals with Down syndrome with IQs ranging between 24 and 48 were administered the Autism Diagnostic Interview-Revised (ADI-R) and the A-PL-ADOS, which are well-validated interview and observational diagnostic measures. Three out of 13 met lifetime criteria on the ADI-R, but none of these three showed behavior that met the criterion for autism on the A-PL-ADOS (although two nearly did so). However, two individuals did meet the A-PL-ADOS criterion and showed behavior that fell only just short of meeting lifetime criteria on the ADI-R. Altogether, 5 individuals with Down syndrome may be considered to show an autism spectrum disorder. Of the remaining 8, some showed a few autistic features, and some showed none. The findings raise both methodological and conceptual issues.

Adolescent↗

PubMed2006

A crossover study of risperidone in children, adolescents and adults with mental retardation.

Risperidone has shown safety and efficacy for aggressive and destructive behaviors in short-term studies. This longer-duration study includes a broad sample. Forty subjects, aged 8-56 years (mean=22), all with mental retardation and 36 with autism spectrum disorders participated in this 22-week crossover study, with 24 weeks of open maintenance thereafter. Of 40 subjects, 23 (57.5%) responded fully (50% decrease in Aberrant Behavior Checklist-Community Irritability subscale score), while 35 subjects (87.5%) showed a 25% decrease. Gender, mood disorder, and antiseizure medications did not alter response. Increased appetite and weight gain were common. Low dose risperidone was effective for aggressive behavior in persons with MR. More long-term studies are needed, incorporating weight control interventions.

Adolescent↗

PubMed2006

The gluten-free, casein-free diet in autism: results of a preliminary double blind clinical trial.

This study tested the efficacy of a gluten-free and casein-free (GFCF) diet in treating autism using a randomized, double blind repeated measures crossover design. The sample included 15 children aged 2-16 years with autism spectrum disorder. Data on autistic symptoms and urinary peptide levels were collected in the subjects' homes over the 12 weeks that they were on the diet. Group data indicated no statistically significant findings even though several parents reported improvement in their children. Although preliminary, this study demonstrates how a controlled clinical trial of the GFCF diet can be conducted, and suggests directions for future research.

Adolescent↗

PubMed2006

Brief report: "the autism epidemic". The registered prevalence of autism in a Swedish urban area.

The objective of this study was to establish rates of diagnosed autism spectrum disorders (ASDs) in a circumscribed geographical region. The total population born in 1977-1994, living in Göteborg Sweden in 2001, was screened for ASD in registers of the Child Neuropsychiatry Clinic. The minimum registered rate of autistic disorder was 20.5 in 10,000. Other ASDs were 32.9 in 10,000, including 9.2 in 10,000 with Asperger syndrome. Males predominated. In the youngest group (7-12 years), 1.23% had a registered diagnosis of ASD. There was an increase in the rate of diagnosed registered ASD over time; the cause was not determined. The increase tended to level off in the younger age cohort, perhaps due to Asperger syndrome cases missed in screening.

Asperger Syndrome↗

PubMed2006

Health care utilization and expenditures for children with autism: data from U.S. national samples.

Little is known about the use of medical services by children who have autism (ASD). Provide nationally representative data for health service utilization and expenditures of children with ASD. Cross-sectional survey using the Medical Expenditure Panel (MEPS), and National (Hospital) Ambulatory Medical Care Surveys (N(H)AMCS). A total of 80 children with ASD were identified from N(H)AMCS (weighted sample size (wss) 186,281), and 31 (wss 340,158) from MEPS. They had more outpatient visits, physician visits, and medications prescribed than children in general. They spent more time during physician visits than other children. Annual expenses for children with autism spectrum disorder (6,132 dollars) were more than for other children (860 dollars). Children with ASD have a substantial burden of medical illness.

Adolescent↗