Neurodevelopmental disorders (NDDs), including autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and intellectual developmental disorder (IDD), are highly prevalent and lack effective treatments, posing significant health challenges. These disorders are frequently comorbid with disruptions in sleep rhythms, and sleep-related indicators are often used to assess disease severity and treatment efficacy. Recent evidence has highlighted the crucial roles of circadian rhythm disturbances and circadian clock gene mutations in the pathogenesis of NDDs. This review focuses on the mechanisms by which circadian rhythm disruptions and circadian clock gene mutations contribute to cognitive, behavioral, and emotional disorders associated with NDDs, particularly through the dysregulation of dopamine system. Additionally, we discussed the potential of targeting the circadian system as novel therapeutic strategies for the treatment of NDDs.
Humans ; Neurodevelopmental Disorders/genetics* ; Attention Deficit Disorder with Hyperactivity/genetics* ; Circadian Rhythm/genetics* ; Autism Spectrum Disorder/genetics* ; Mutation ; Intellectual Disability/genetics* ; Circadian Clocks/physiology* ; Dopamine/metabolism*

The patient is a male neonate born at term. He was admitted 16 minutes after birth due to stridor and inspiratory respiratory distress. Physical examination revealed a cleft palate, and a grade II systolic ejection murmur was audible at the left sternal border. Whole exome sequencing identified a heterozygous variant in the SON gene, c.5753-5756del (p.Val1918GlufsTer87), which was absent in either parent, indicating a de novo mutation. According to the guidelines of the American College of Medical Genetics and Genomics, this was classified as a "pathogenic variant" leading to a diagnosis of Zhu-Tokita-Takenouchi-Kim (ZTTK) syndrome. Upon admission, symptomatic supportive treatment was provided. Follow-up at the age of 8 months revealed persistent stridor; the infant could only consume small amounts of milk and was unable to sit steadily. This patient represents the youngest reported case to date, and his symptoms expand the clinical spectrum of the disease, providing valuable insights for clinical diagnosis and treatment.
Humans ; Infant, Newborn ; Male ; Minor Histocompatibility Antigens/genetics* ; DNA-Binding Proteins/genetics* ; Rare Diseases/genetics* ; Neurodevelopmental Disorders/genetics*

OBJECTIVE: To explore the clinical characteristics and genetic etiology for two children with Neurodevelopmental disorder with hypotonia, stereotypic hand movements, and impaired language (MEDHSIL). METHODS: Two children who had visited the Ningbo Women and Children's Hospital on October 15, 2021 were selected as the study subjects. Whole exome sequencing (WES) was carried out for both patients. Candidate variants were verified by Sanger sequencing of their family members. RESULTS: The two children were respectively found to harbor a heterozygous c.138delC (p.Ile47Serfs*42) variant and a c.833del (p.L278*) variant of the MEF2C gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted to be pathogenic (PVS1+PS2+PM2_Supporting). CONCLUSION The c.138delC and c.833del variants of the MEF2C gene probably underlay the pathogenesis of MEDHSIL in the two children. Above findings have enriched the mutational spectrum of the MEF2C gene and enabled genetic counseling for their families.
Child ; Humans ; Family ; Genetic Counseling ; Language ; MEF2 Transcription Factors/genetics* ; Muscle Hypotonia/genetics* ; Neurodevelopmental Disorders

OBJECTIVES: To analyze the clinical and genetic characteristics of children with autosomal dominant neurodevelopmental disorders caused by kinesin family member 1A (KIF1A) gene variation. METHODS: Clinical and genetic testing data of 6 children with KIF1A gene de novo heterozygous variation diagnosed in Shanghai Children's Medical Center Affiliated to Shanghai Jiao Tong University School of Medicine from the year 2018 to 2020 were retrospectively analyzed. Pathogenic variants were identified based on whole exome sequencing, and verified by Sanger sequencing. Moreover, the effect of variants on three-dimensional structure and stability of protein was analyzed by bioinformatics. RESULTS: Among 6 patients there were 4 males and 2 females, and the age of consultation varied from 7 months to 18 years. All cases had varying degrees of motor developmental delay since childhood, and 4 of them had gait abnormalities or fell easily. In addition, 2 children were accompanied by delayed mental development, epilepsy and abnormal eye development. Genetic tests showed that all 6 cases had heterozygous de novo variations of KIF1A gene, including 4 missense mutations c.296C>T (p.T99M), c.761G>A (p.R254Q), c.326G>T (p.G109V), c.745C>G (p.L249V) and one splicing mutation c.798+1G>A, among which the last three variants have not been previously reported. Bioinformatics analysis showed that G109V and L249V may impair their interaction with the neighboring amino acid residues, thereby impacting protein function and reducing protein stability, and were assessed as "likely pathogenic". Meanwhile, c.798+1G>A may damage an alpha helix in the motor domain of the KIF1A protein, and was assessed as "likely pathogenic". CONCLUSIONS KIF1A-associated neurological diseases are clinically heterogeneous, with motor developmental delay and abnormal gait often being the most common clinical features. The clinical symptoms in T99M carriers are more severe, while those in R254Q carriers are relatively mild.
Male ; Female ; Humans ; Child ; Retrospective Studies ; China ; Mutation ; Epilepsy/genetics* ; Neurodevelopmental Disorders/genetics* ; Kinesins/genetics*

OBJECTIVE: To explore the genetic basis for a child with Neurodevelopmental disorder with or without autistic features and/or structural brain abnormalities (NEDASB). METHODS: A child with NEDASB who presented at the Third Affiliated Hospital of Zhengzhou University in July 2021 was selected as the subject. Peripheral blood samples of the child and her parents were collected and subjected to high-throughput sequencing. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: The child was found to harbor a heterozygous c.820_828delinsCTTCA (p.Thr274Leufs*121) variant of the NOVA2 gene, for which both of her parents were of wild type. The variant was predicted as pathogenic based on the guidelines from the American College of Medical Genetics and Genomics. CONCLUSION The heterozygous c.820_828delinsCTTCA (p.Thr274Leufs*121) variant of the NOVA2 gene probably underlay the disease in this child. Above finding has enriched the spectrum of NOVA2 gene variants and provided a basis for genetic counseling and prenatal diagnosis for this family.
Child ; Female ; Humans ; Pregnancy ; Autistic Disorder/genetics* ; Brain ; Computational Biology ; Genetic Counseling ; Mutation ; Nerve Tissue Proteins/genetics* ; Neuro-Oncological Ventral Antigen ; Neurodevelopmental Disorders ; RNA-Binding Proteins

BACKGROUND: Significant brain volume deviation is an essential phenotype in children with neurodevelopmental delay (NDD), but its genetic basis has not been fully characterized. This study attempted to analyze the genetic factors associated with significant whole-brain deviation volume (WBDV). METHODS: We established a reference curve based on 4222 subjects ranging in age from the first postnatal day to 18 years. We recruited only NDD patients without acquired etiologies or positive genetic results. Cranial magnetic resonance imaging (MRI) and clinical exome sequencing (2742 genes) data were acquired. A genetic burden test was performed, and the results were compared between patients with and without significant WBDV. Literature review analyses and BrainSpan analysis based on the human brain developmental transcriptome were performed to detect the potential role of genetic risk factors in human brain development. RESULTS: We recruited a total of 253 NDD patients. Among them, 26 had significantly decreased WBDV (<-2 standard deviations [SDs]), and 14 had significantly increased WBDV (>+2 SDs). NDD patients with significant WBDV had higher rates of motor development delay (49.8% [106/213] vs . 75.0% [30/40], P  = 0.003) than patients without significant WBDV. Genetic burden analyses found 30 genes with an increased allele frequency of rare variants in patients with significant WBDV. Analyses of the literature further demonstrated that these genes were not randomly identified: burden genes were more related to the brain development than background genes ( P  = 1.656e -9 ). In seven human brain regions related to motor development, we observed burden genes had higher expression before 37-week gestational age than postnatal stages. Functional analyses found that burden genes were enriched in embryonic brain development, with positive regulation of synaptic growth at the neuromuscular junction, positive regulation of deoxyribonucleic acid templated transcription, and response to hormone, and these genes were shown to be expressed in neural progenitors. Based on single cell sequencing analyses, we found TUBB2B gene had elevated expression levels in neural progenitor cells, interneuron, and excitatory neuron and SOX15 had high expression in interneuron and excitatory neuron. CONCLUSION Idiopathic NDD patients with significant brain volume changes detected by MRI had an increased prevalence of motor development delay, which could be explained by the genetic differences characterized herein.
Child ; Humans ; Neurodevelopmental Disorders/epidemiology* ; Genetic Testing ; Phenotype ; Brain/pathology* ; Genetic Background ; SOX Transcription Factors/genetics*

OBJECTIVE: To explore the clinical phenotype and genetic basis of a child with early onset neurodevelopmental disorder with involuntary movement (NEDIM). METHODS: A child who presented at Department of Neurology of Hunan Children's Hospital on October 8, 2020 was selected as the study subject. Clinical data of the child were collected. Genomic DNA was extracted from peripheral blood samples of the child and his parents. Whole exome sequencing (WES) was carried out for the child. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. Relevant literature was searched from the CNKI, PubMed and Google Scholar databases to summarize the clinical phenotypes and genetic variants of the patients. RESULTS: This child was a 3-year-and-3-month boy with involuntary trembling of limbs and motor and language delay. WES revealed that the child has harbored a c.626G>A (p.Arg209His) variant of the GNAO1 gene. Sanger sequencing confirmed that neither of his parents has carried the same variant. The variant had been reported in HGMD and ClinVar databases, but not in the dbSNP, ExAC and 1000 Genomes databases. Prediction with SIFT, PolyPhen-2, and Mutation Taster online software suggested that the variant may be deleterious to the protein function. By UniProt database analysis, the encode amino acid is highly conserved among various species. Prediction with Modeller and PyMOL software indicated that the variant may affect the function of GαO protein. Based on the guideline of the American College of Medical Genetics and Genomics (ACMG), the variant was rated as pathogenic. CONCLUSION The GNAO1 gene c.626G>A (p.Arg209His) variant probably underlay the NEDIM in this child. Above finding has expanded the phenotypic spectrum of GNAO1 gene c.626G>A (p.Arg209His) variant and provided a reference for clinical diagnosis and genetic counseling.
Humans ; Computational Biology ; Genetic Counseling ; Genomics ; Mutation ; Neurodevelopmental Disorders/genetics* ; Dyskinesias ; GTP-Binding Protein alpha Subunits, Gi-Go

The radial migration of cortical pyramidal neurons (PNs) during corticogenesis is necessary for establishing a multilayered cerebral cortex. Neuronal migration defects are considered a critical etiology of neurodevelopmental disorders, including autism spectrum disorders (ASDs), schizophrenia, epilepsy, and intellectual disability (ID). TRIO is a high-risk candidate gene for ASDs and ID. However, its role in embryonic radial migration and the etiology of ASDs and ID are not fully understood. In this study, we found that the in vivo conditional knockout or in utero knockout of Trio in excitatory precursors in the neocortex caused aberrant polarity and halted the migration of late-born PNs. Further investigation of the underlying mechanism revealed that the interaction of the Trio N-terminal SH3 domain with Myosin X mediated the adherence of migrating neurons to radial glial fibers through regulating the membrane location of neuronal cadherin (N-cadherin). Also, independent or synergistic overexpression of RAC1 and RHOA showed different phenotypic recoveries of the abnormal neuronal migration by affecting the morphological transition and/or the glial fiber-dependent locomotion. Taken together, our findings clarify a novel mechanism of Trio in regulating N-cadherin cell surface expression via the interaction of Myosin X with its N-terminal SH3 domain. These results suggest the vital roles of the guanine nucleotide exchange factor 1 (GEF1) and GEF2 domains in regulating radial migration by activating their Rho GTPase effectors in both distinct and cooperative manners, which might be associated with the abnormal phenotypes in neurodevelopmental disorders.
Autism Spectrum Disorder/metabolism* ; Cell Movement/genetics* ; Humans ; Interneurons/metabolism* ; Neurodevelopmental Disorders/genetics* ; Neurons/metabolism* ; Rho Guanine Nucleotide Exchange Factors/genetics*

Mutations of the X-linked methyl-CpG-binding protein 2 (MECP2) gene in humans are responsible for most cases of Rett syndrome (RTT), an X-linked progressive neurological disorder. While genome-wide screens in clinical trials have revealed several putative RTT-associated mutations in MECP2, their causal relevance regarding the functional regulation of MeCP2 at the etiologic sites at the protein level requires more evidence. In this study, we demonstrated that MeCP2 was dynamically modified by O-linked-β-N-acetylglucosamine (O-GlcNAc) at threonine 203 (T203), an etiologic site in RTT patients. Disruption of the O-GlcNAcylation of MeCP2 specifically at T203 impaired dendrite development and spine maturation in cultured hippocampal neurons, and disrupted neuronal migration, dendritic spine morphogenesis, and caused dysfunction of synaptic transmission in the developing and juvenile mouse cerebral cortex. Mechanistically, genetic disruption of O-GlcNAcylation at T203 on MeCP2 decreased the neuronal activity-induced induction of Bdnf transcription. Our study highlights the critical role of MeCP2 T203 O-GlcNAcylation in neural development and synaptic transmission potentially via brain-derived neurotrophic factor.
Animals ; Humans ; Methyl-CpG-Binding Protein 2/metabolism* ; Mice ; Neurodevelopmental Disorders/genetics* ; Rett Syndrome/genetics* ; Synaptic Transmission ; Threonine

Autism spectrum disorder (ASD) is a set of neurodevelopmental disorders. Patients usually exhibit certain degree of social interaction impairment in accompany with impairment in language development as well as repetitive behaviors or interests. In recent years, ASD-related variants, genes, functional pathways, and expression patterns in the brain have been discovered, along with advance in sequencing techniques. This article reviews various aspects of genetic research in association with ASD.
Autism Spectrum Disorder/genetics* ; Cognition ; Genetic Research ; Humans ; Neurodevelopmental Disorders