Journal of Neurodevelopmental Disorders最新文献

Selenium, an essential micronutrient integrated into selenoproteins as selenocysteine, is fundamental to human health. These selenoproteins are vital for several physiological functions, including maintaining redox balance, safeguarding DNA, and metabolizing thyroid hormones, and are produced via complex pathways involving Sec-tRNA^[Ser]Sec, the SECIS element, and specific proteins such as eEFSec. This study investigates a 4-year-old girl with global developmental delay and cerebellar atrophy, revealing compound heterozygous variants in the EEFSEC gene (p.V488Dfs*113 and p.R443P) through extensive genetic analysis and whole exome sequencing. Both functional prediction tools and structural analysis underscored the detrimental impact of the p.R443P variant. Notably, the patient's plasma exhibited elevated levels of oxidized fatty acid metabolites compared to those in healthy controls, suggesting an impairment in antioxidant mechanisms. This case link a human disease directly to variants in the EEFSEC gene, emphasizing its vital role in cerebellar atrophy and the broader implications for genetic disorders related to defects in selenoprotein synthesis. The results highlight the significance of genetic screening for EEFSEC variants in similar cases, potentially broadening the spectrum of known genetic subtypes associated with selenoprotein translation abnormalities.

The most common genetic cause of intellectual and developmental disability is trisomy of human chromosome 21 (trisomy 21) or Down syndrome. Relative to the general population, individuals with Down syndrome heterogeneously experience atypical morphogenesis, a distinct neurocognitive profile, and a unique spectrum of diverse medical conditions that impact every major organ system. How trisomy 21 results in the highly variable manifestations of Down syndrome remains largely unknown and an active area of heavy investigation with therapeutic implications. For example, common inflammatory and metabolic signatures have begun to emerge across various co-occurring conditions in Down syndrome with assorted impacts on diverse yet intertwined organ systems that could directly or indirectly impact brain health. Here, we review current progress, resources, knowledge gaps, and bottlenecks for precision medicine approaches to promote brain health across the lifespan among individuals with Down syndrome within the larger context of research efforts geared towards our other distinct yet intertwined organ systems. Within this framework, we advocate for interdisciplinary pursuit of systems-level biomarkers to facilitate holistic intervention strategies that precisely benefit individuals with trisomy 21 each experiencing Down syndrome in their own unique way. To this end, we quantitatively assess clinical studies that are actively recruiting participants with Down syndrome and provide historical context through summary figures sourced to user-friendly tables that have been curated from federal websites to empower efficient exploration of research opportunities for interdisciplinary collaborations.

Background: Altered white matter (WM) is consistently reported in patients with phenylketonuria (PKU). However, the knowledge about WM microstructural integrity in early-treated adults with classical PKU and its relationship with cognition and metabolic parameters is inconclusive. This study aims to explore the cerebral WM microstructural alterations in adult patients with early-treated classical PKU and their association with blood phenylalanine (Phe) levels and neuropsychological performance using whole-brain diffusion tensor imaging (DTI).

Methods: Twenty-nine patients with early-treated classical PKU (mean age = 30.86, SD = 7.74) and 31 healthy controls (mean age = 32.45, SD = 9.40) underwent neuropsychological assessment and MRI. Phe dry blood spot (DBS-Phe) samples, along with venous Phe levels, were collected from the PKU sample to calculate the index of dietary control (IDC). Tract-based spatial statistics (TBSS) of the mean diffusivity (MD), and fractional anisotropy (FA), were carried out with FSL v6.0.4 to assess between-group differences and to explore associations with both cognitive and clinical data.

Results: Patients exhibited a widespread white matter tract involvement, with lower MD and higher FA values compared to controls. The most affected tracts were the inferior longitudinal fasciculus and inferior fronto-occipital fasciculus for MD, and the anterior corona radiata, uncinate fasciculus and forceps minor for FA. MD negatively correlated with IDC and venous Phe levels, whereas FA negatively correlated with full-scale intelligence quotient (FSIQ) (p-value ≤0.05 FWE-corrected).

Conclusions: Microstructural WM alterations were present in adults with early-treated classical PKU, and these abnormalities were related to global intelligence and metabolic control markers. Although our results suggest the importance of proper disease management, further studies are needed to determine its long-term relevance.

ANKRD17 has recently been implicated in intellectual disability (ID) and autism spectrum disorder (ASD); however, the underlying molecular mechanisms remain unclear. Using trio whole-exome sequencing (Trio-WES) and chromosomal microarray analysis (CMA), we identified two unrelated cases with novel de novo heterozygous ANKRD17 variants. Case 1 describes a fetus with multiple congenital anomalies, where genetic analysis revealed a microdeletion at 4q13.3 truncating the ANKRD17 gene. Case 2 involves a 12-year-old male presenting with mild ID and progressive social impairments, associated with a NM_032217.5: c.1252 C > T (p.Arg418*) variation in ANKRD17. Our study highlighted in mouse models an association between Ankrd17 haploinsufficiency and deficits in social behavior, spatial learning and memory, as well as elevated anxiety. Furthermore, our studies suggest dysregulation of synaptic proteins and mitochondrial function, along with impaired neural circuits following Ankrd17 knockdown. These results expand the genetic and phenotypic spectrum of ANKRD17-related disorders, underscore the critical role of mitochondrial dysfunction in the pathophysiology of ANKRD17-related ID and ASD.

Background: This study explored Trajectories of Diagnoses (TDs) preceding a first diagnosis of autism in adulthood.

Methods: This retrospective cohort study used health administrative data from Quebec, Canada, and included all adults with a first recorded diagnosis of autism between 2012 and 2017. A TDs was defined as a succession of medical records of psychiatric and/or neurodevelopmental conditions over time. These TDs were retrospectively analyzed from 2002 to 2017, using a state sequence analysis of diagnoses, in order: Autism, Intellectual or developmental disabilities (IDDs), Schizophrenia spectrum disorder (SSD), Bipolar Disorder (BD), Depressive Disorder (DD), Anxiety Disorder (AD), Attention-deficit/hyperactivity disorder (ADHD), and Other psychiatric and/or neurodevelopmental conditions.

Results: The cohort included 2799 adults with a first recorded diagnosis of autism between 2012 and 2017. Several psychiatric and/or neurodevelopmental conditions were recorded since 2002, including AD (77.5%), DD (58.0%), SSD (49.4%), BD (48.3%), and IDDs (33.2%). Results revealed 5 distinct types of TDs. Types 1 (63.8%), 2 (17.6%) and 3 (6%) represented individuals in younger age groups with similar characteristics but with very different sequences of diagnoses, characterized by mixed diagnoses in type 1, SSD and AD in Type 2, and IDDs, DD, AD, and ADHD in type 3. Types 4 and 5 (9.0% and 3.6%), representing middle-aged/older groups, displayed distinctive TDs associated with high healthcare use, almost entirely associated with SSD (Type 4) and BD (Type 5).

Conclusion: This study proposes a complementary examination of the multiple pathways to diagnosis experienced by adults, highlighting the need to address differential diagnosis and co-occurring psychiatric and neurodevelopmental conditions.

Objective: Attention-deficit hyperactivity disorder (ADHD) is a common neuropsychiatric disorder with a significant genetic component. The latest genome-wide association study (GWAS) meta-analysis of ADHD identified 27 whole-genome significant risk loci in the European population. However, genetic risk factors for ADHD are less well-characterized in the Asian population, especially for low-frequency / rare variants.

Methods: In this study, we aimed to investigate the contributions of both common and low-frequency / rare variants to ADHD in a Hong Kong sample. Our sample comprised 279 cases and 432 controls who underwent genotyping using the Illumina Infinium Global Screening Array. We employed various analytical methods at different levels, while also leveraging multi-omics data and large-scale summary statistics to comprehensively analyze the genetic basis of ADHD.

Results: We identified 41 potential genomic risk loci with a suggestive association (p < 1e^-4), pointing to 111 candidate risk genes, which were enriched for genes differentially expressed during late infancy brain development. Furthermore, tissue enrichment analysis implicated the involvement of the cerebellum. At the polygenic level, we also discovered a strong genetic correlation with resting-state functional MRI connectivity of the cerebellum involved in the attention/central executive and subcortical-cerebellum networks. In addition, an accumulation of ADHD common-variant risks found in European ancestry samples was found to be significantly associated with ADHD in the current study. In low-frequency / rare variant analyses, we discovered the correlations between ADHD and collapsing effects of rare damaging variants in TEP1, MTMR10, DBH, TBCC, and ANO1. Based on biological and functional profiles of the potential risk genes and gene sets, both common and low-frequency / rare variant analyses demonstrated that ADHD genetic risk was associated with immune processes.

Conclusions: These findings re-validate the abnormal development of the neural system in ADHD and extend the existing neuro-dysfunction hypothesis to a multi-system perspective. The current study identified convergent risk factors from common and low-frequency / rare variants, which implicates vulnerability in late-infancy brain development, affecting especially the cerebellum, and the involvement of immune processes.

Background: 16p11.2 deletion syndrome (16p11.2DS) is a recurrent CNV that occurs de novo in approximately 70% of cases and confers risk for neurodevelopmental disorders, including intellectual disability (ID) and autism spectrum disorders (ASD). The current study focusses on developmental milestones, cognitive profiles and longitudinal cognitive trajectories.

Methods: In-person assessments, digital medical records and parental interviews on developmental history of 24 children (5-16 years) with a confirmed BP4-BP5 16p11.2DS were reviewed and analysed for developmental milestones (motor, language, continence). Standardised intelligence tests were administered in all children, and longitudinal IQ-data were available for a subgroup (79%, 19/24).

Results: Motor, language, and continence milestones were delayed. Average IQ was in the borderline range (IQ 71) with 46% (11/24) having borderline IQ (IQ 70-84). Both intra- and interindividual variability were found across the five cognitive domains with significant discrepancies between verbal and non-verbal skills in 55% (11/20). Longitudinal IQ-data indicate that school-aged children with 16p11.2DS perform statistically significantly lower at the second time point (p < 0.001) with 58% showing a growing into deficit trajectory.

Conclusion: Delayed motor, language and continence milestones are common in 16p11.2DS carriers. School-aged children with 16p11.2DS show increasing cognitive impairments over time, pointing to the need for early diagnosis, regular cognitive follow-up and individualised intervention. The high prevalence of disharmonic IQ-profiles highlights the importance of expanding the focus beyond full-scale IQ (FSIQ) outcomes. Future studies in larger cohorts including carrier relatives are needed to gain more insight into the penetrance and phenotypic variability of 16p11.2DS.

Cumulative evidence suggests neurodevelopmental disorders are closely related. The risk of these disorders is increased by a series of copy number variant syndromes - phenotypically heterogeneous genetic disorders, present in a minority of the population. Recent models suggest that a disruption in the balance between excitatory and inhibitory neural activity may contribute to the aetiology of neurodevelopmental disorders, and may be additionally disturbed in copy number variant syndromes. In this systematic review, the databases PubMed, Embase, and Scopus were searched for studies of excitation/inhibition imbalance in relation to neurodevelopmental disorders in human copy number variant samples. A total of 53 studies were included, representing a variety of copy number variants and research methodologies. The resulting data suggests excitation/inhibition balance is indeed disrupted in different copy number variant populations, providing insight into a putative mechanism of both idiopathic and genetic neurodevelopmental disorders. However, the high level of heterogeneity in the data set, alongside emerging techniques for excitation/inhibition assessment, prompts further investigation of this field.

Background: Polygenic scores (PGS) are widely used in psychiatric genetic associations studies due to their predictive power for focal outcomes. However, they lack discriminatory power, in part due to the high degree of genetic overlap between psychiatric disorders. The lack of prediction specificity limits the clinical utility of psychiatric PGS, particularly for diagnostic applications. The goal of the study was to enhance the discriminatory power of psychiatric PGS for two highly comorbid and genetically correlated neurodevelopmental disorders in ADHD and autism spectrum disorder (ASD).

Methods: Genomic structural equation modeling (GenomicSEM) was used to generate novel PGS for ADHD and ASD by accounting for the genetic overlap between these disorders (and eight others) to achieve greater discriminatory power in non-focal outcome predictions. PGS associations were tested in two large independent samples - the Philadelphia Neurodevelopmental Cohort (N = 4,789) and the Simons Foundation Powering Autism Research for Knowledge (SPARK) ASD and sibling controls (N = 5,045) cohort.

Results: PGS from GenomicSEM achieved superior discriminatory power in terms of showing significantly attenuated associations with non-focal outcomes relative to traditionally computed PGS for these disorders. Additionally, genetic correlations between GenomicSEM PGS for ASD and ADHD were significantly attenuated in cross-trait associations with other psychiatric disorders and outcomes.

Conclusions: Psychiatric PGS associations are likely inflated by the high degree of genetic overlap between the psychiatric disorders. Methods such as GenomicSEM can be used to refine PGS signals to be more disorder-specific, thereby enhancing their discriminatory power for future diagnostic applications.

Objective: We describe the development and validation of PANDABox-EEG, a novel protocol for remote EEG assessment with no on-site technician, tailored for Angelman syndrome (AS). We argue that this protocol is reliable, valid, and widely acceptable for use in families affected by Angelman syndrome.

Background: AS is a rare neurogenetic condition characterized by developmental delays, sleep problems, seizures, and a happy demeanor. People with AS are frequently monitored via EEG to inform clinical care, and EEG-measured delta activity has been proposed as a reliable biomarker to monitor treatment effectiveness. Traditional EEG assessments pose logistical and financial burdens for families due to the need to travel to a medical center to complete assessments. Telehealth methods, however, offer a pathway forward.

Methods: PANDABox-EEG was developed through multidisciplinary collaboration with psychologists, psychophysiologists, engineers, and special-education scholars, incorporating caregiver feedback and user-centered design principles. It pairs PANDABox, a telehealth platform for biobehavioral assessment in rare disorders, with a dry electrode EEG system. Twenty-eight participants (7 AS, 7 siblings, 14 caregivers) completed three 5-min EEG sessions each over the course of a week. Caregivers were asked to provide feedback on acceptability of the design, and EEG data was quantified and assessed for metrics of reliability and validity.

Results: PANDABox-EEG demonstrated high feasibility and acceptability, with 91% of caregivers reporting strong satisfaction assessment comfort. EEG data quality was promising, with high internal consistency (split-half reliability range for children with AS: r = .96-.98) and test-retest reliability for delta power among (test-retest reliability range for children with AS: ρ = .88-.96). Finally, we successfully detected the characteristic increased delta power in AS (effect size between AS and non-AS siblings: d = 1.56-2.85) and its association with age (effect size between non-AS siblings and caregivers: d = 2.19-2.72).

Conclusion: PANDABox-EEG provides a feasible, cost-effective, and reliable method for remote EEG assessment in AS. Its high caregiver satisfaction and ability to capture relevant neurophysiological markers suggest potential for broader application. With further validation, PANDABox-EEG can enhance accessibility and inclusivity, benefiting clinical management and research in AS and other clinical populations in need of frequent EEG monitoring by eliminating the need to travel.