A recurrent SHANK3 frameshift variant in Autism Spectrum Disorder

Clinical profiling and medical management of Israeli individuals with Phelan McDermid syndrome

BACKGROUND

Phelan-McDermid syndrome (PMS) is a neurodevelopmental disorder, caused by haploinsufficiency of the SHANK3 gene. In addition to global developmental delay (GDD)/intellectual disability (ID) and autism spectrum disorder (ASD), PMS is characterized by multiple neurologic, behavioral and multisystemic manifestations.

METHODS

We aimed to establish a database of individuals with PMS in Israel. All participants underwent a detailed evaluation at a single medical center, and demographic, clinical, and genetic data were collected.

RESULTS

Seventeen unrelated individuals with PMS (mean age 10 ± 8.2 years; range, 2.5-36 years) were enrolled (10 females, 59%), all of Jewish descent. Twelve cases (70%) were caused by deletions in chromosomal region 22q13.3, including mosaicism, ring chromosome and unbalanced translocation. The other 5 (30%) cases were due to single nucleotide variants (SNVs), while the de novo SNV c.3904dup (p.Ala1302GlyfsTer69), recurred in 3 cases. All 17 participants had GDD/ID (which was severe in 10, 59%), and ASD and seizures were present in 12 (70%) and 8 (47%) individuals, respectively. Additional frequent manifestations were sleep difficulties in 13 individuals (76%), bowel movement disorders in 13 (76%), urinary track involvement in 8 (47%) and endocrine disorders in 6 (35%). Abnormal but nonspecific findings on prenatal ultrasonography were noted in 3 participants (18%). The most common perinatal complication was prolonged jaundice in 5 infants (29%). Different medical treatment modalities, including cannabidiol (CBD) full-spectrum oil extracts, were used to ease symptoms, with variable results.

CONCLUSIONS

Our experience adds to current knowledge about clinical manifestations and potential symptomatic treatment of PMS in Israel. These findings may promote clinical research and serve as infrastructure for future clinical trials.

Structural Variations Identified in Patients with Autism Spectrum Disorder (ASD) in the Chinese Population: A Systematic Review of Case-Control Studies

Autistic spectrum disorder (ASD) is a neurodevelopmental disability characterised by the impairment of social interaction and communication ability. The alarming increase in its prevalence in children urged researchers to obtain a better understanding of the causes of this disease. Genetic factors are considered to be crucial, as ASD has a tendency to run in families. In recent years, with technological advances, the importance of structural variations (SVs) in ASD began to emerge. Most of these studies, however, focus on the Caucasian population. As a populated ethnicity, ASD shall be a significant health issue in China. This systematic review aims to summarise current case-control studies of SVs associated with ASD in the Chinese population. A list of genes identified in the nine included studies is provided. It also reveals that similar research focusing on other genetic backgrounds is demanded to manifest the disease etiology in different ethnic groups, and assist the development of accurate ethnic-oriented genetic diagnosis.

Trans-synaptic Association of Vesicular Zinc Transporter 3 and Shank3 Supports Synapse-Specific Dendritic Spine Structure and Function in the Mouse Auditory Cortex

Shank3 is a synaptic scaffolding protein that assists in tethering and organizing structural proteins and glutamatergic receptors in the postsynaptic density of excitatory synapses. The localization of Shank3 at excitatory synapses and the formation of stable Shank3 complexes is regulated by the binding of zinc to the C-terminal sterile-alpha-motif (SAM) domain of Shank3. Mutations in the SAM domain of Shank3 result in altered synaptic function and morphology, and disruption of zinc in synapses that express Shank3 leads to a reduction of postsynaptic proteins important for synaptic structure and function. This suggests that zinc supports the localization of postsynaptic proteins via Shank3. Many regions of the brain are highly enriched with free zinc inside glutamatergic vesicles at presynaptic terminals. At these synapses, zinc transporter 3 (ZnT3) moves zinc into vesicles where it is co-released with glutamate. Alterations in ZnT3 are implicated in multiple neurodevelopmental disorders, and ZnT3 knock-out (KO) mice-which lack synaptic zinc-show behavioral deficits associated with autism spectrum disorder and schizophrenia. Here we show that male and female ZnT3 KO mice have smaller dendritic spines and miniature excitatory postsynaptic current amplitudes than wildtype (WT) mice in the auditory cortex. Additionally, spine size deficits in ZnT3 KO mice are restricted to synapses that express Shank3. In WT mice, synapses that express both Shank3 and ZnT3 have larger spines compared to synapses that express Shank3 but not ZnT3. Together these findings suggest a mechanism whereby presynaptic ZnT3-dependent zinc supports postsynaptic structure and function via Shank3 in a synapse-specific manner.

New advances in the diagnosis and treatment of autism spectrum disorders

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders that affect individuals' social interactions, communication skills, and behavioral patterns, with significant individual differences and complex etiology. This article reviews the definition and characteristics of ASD, epidemiological profile, early research and diagnostic history, etiological studies, advances in diagnostic methods, therapeutic approaches and intervention strategies, social and educational integration, and future research directions. The highly heritable nature of ASD, the role of environmental factors, genetic-environmental interactions, and the need for individualized, integrated, and technology-driven treatment strategies are emphasized. Also discussed is the interaction of social policy with ASD research and the outlook for future research and treatment, including the promise of precision medicine and emerging biotechnology applications. The paper points out that despite the remarkable progress that has been made, there are still many challenges to the comprehensive understanding and effective treatment of ASD, and interdisciplinary and cross-cultural research and global collaboration are needed to further deepen the understanding of ASD and improve the quality of life of patients.

Early-onset catatonia associated with SHANK3 mutations: looking at the autism spectrum through the prism of psychomotor phenomena

Background

Individuals with Phelan-McDermid syndrome (PMS) present with a wide range of diagnoses: autism spectrum disorder, intellectual disability, or schizophrenia. Differences in the genetic background could explain these different neurodevelopmental trajectories. However, a more parsimonious hypothesis is to consider that they may be the same phenotypic entity. Catatonic disturbances occasionally reported from adolescence onwards in PMS prompts exploration of the hypothesis that this clinical entity may be an early-onset form of catatonia. The largest cohort of children with childhood catatonia was studied by the Wernicke-Kleist-Leonhard school (WKL school), which regards catatonia as a collection of qualitative abnormalities of psychomotricity that predominantly affecting involuntary motricity (reactive and expressive). The aim of this study was to investigate the presence of psychomotor signs in three young adults carrying a mutation or intragenic deletion of the SHANK3 gene through the prism of the WKL school conception of catatonia.

Methods

This study was designed as an exploratory case study. Current and childhood psychomotor phenomena were investigated through semi-structured interviews with the parents, direct interaction with the participants, and the study of documents reporting observations of the participants at school or by other healthcare professionals.

Results

The findings show catatonic manifestations from childhood that evolved into a chronic form, with possible phases of sub-acute exacerbations starting from adolescence.

Conclusion

The presence of catatonic symptoms from childhood associated with autistic traits leads us to consider that this singular entity fundamentally related to SHANK3 mutations could be a form of early-onset catatonia. Further case studies are needed to confirm our observations.

Prenatal delta-9-tetrahydrocannabinol exposure is associated with changes in rhesus macaque DNA methylation enriched for autism genes

BACKGROUND

With the growing availability of cannabis and the popularization of additional routes of cannabis use beyond smoking, including edibles, the prevalence of cannabis use in pregnancy is rapidly increasing. However, the potential effects of prenatal cannabis use on fetal developmental programming remain unknown.

RESULTS

We designed this study to determine whether the use of edible cannabis during pregnancy is deleterious to the fetal and placental epigenome. Pregnant rhesus macaques consumed a daily edible containing either delta-9-tetrahydrocannabinol (THC) (2.5 mg/7 kg/day) or placebo. DNA methylation was measured in 5 tissues collected at cesarean delivery (placenta, lung, cerebellum, prefrontal cortex, and right ventricle of the heart) using the Illumina MethylationEPIC platform and filtering for probes previously validated in rhesus macaque. In utero exposure to THC was associated with differential methylation at 581 CpGs, with 573 (98%) identified in placenta. Loci differentially methylated with THC were enriched for candidate autism spectrum disorder (ASD) genes from the Simons Foundation Autism Research Initiative (SFARI) database in all tissues. The placenta demonstrated greatest SFARI gene enrichment, including genes differentially methylated in placentas from a prospective ASD study.

CONCLUSIONS

Overall, our findings reveal that prenatal THC exposure alters placental and fetal DNA methylation at genes involved in neurobehavioral development that may influence longer-term offspring outcomes. The data from this study add to the limited existing literature to help guide patient counseling and public health polices focused on prenatal cannabis use in the future.

Comprehensive analysis of the coding and non-coding RNA transcriptome expression profiles of hippocampus tissue in tx-J animal model of Wilson's disease

Wilson's disease (WD) is an autosomal recessive disorder with a genetic basis. The predominant non-motor symptom of WD is cognitive dysfunction, although the specific genetic regulatory mechanism remains unclear. Tx-J mice, with an 82% sequence homology of the ATP7B gene to the human gene, are considered the most suitable model for WD. This study employs deep sequencing to investigate the differences in RNA transcript profiles, both coding and non-coding, as well as the functional characteristics of the regulatory network involved in WD cognitive impairment. The cognitive function of tx-J mice was evaluated using the Water Maze Test (WMT). Long non-coding RNA (lncRNA), circular RNA (circRNA), and messenger RNA (mRNA) profiles were analyzed in the hippocampal tissue of tx-J mice to identify differentially expressed RNAs (DE-RNAs). Subsequently, the DE-RNAs were used to construct protein-protein interaction (PPI) networks, as well as DE-circRNAs and lncRNAs-associated competing endogenous RNA (ceRNA) expression networks, and coding-noncoding co-expression (CNC) networks. To elucidate their biological functions and pathways, the PPI and ceRNA networks were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. A total of 361 differentially expressed mRNAs (DE-mRNAs), comprising 193 up-regulated and 168 down-regulated mRNAs, 2627 differentially expressed long non-coding RNAs (DE-lncRNAs), consisting of 1270 up-regulated and 1357 down-regulated lncRNAs, and 99 differentially expressed circular RNAs (DE-circRNAs), consisting of 68 up-regulated and 31 down-regulated circRNAs, were observed in the tx-J mice group when compared to the control mice group. Gene Ontology (GO) and pathway analyses revealed that DE-mRNAs were enriched in cellular processes, calcium signaling pathways, and mRNA surveillance pathways. In contrast, the DE-circRNAs-associated competing endogenous RNA (ceRNA) network was enriched for covalent chromatin modification, histone modification, and axon guidance, whereas the DE-lncRNAs-associated ceRNA network was enriched for dendritic spine, regulation of cell morphogenesis involved in differentiation, and mRNA surveillance pathway. The study presented the expression profiles of lncRNA, circRNA, and mRNA in the hippocampal tissue of tx-J mice. Furthermore, the study constructed PPI, ceRNA, and CNC expression networks. The findings are significant in comprehending the function of regulatory genes in WD associated with cognitive impairment. These results also offer valuable information for the diagnosis and treatment of WD.

Autism Spectrum Disorder: Neurodevelopmental Risk Factors, Biological Mechanism, and Precision Therapy

Autism spectrum disorder (ASD) is a heterogeneous, behaviorally defined neurodevelopmental disorder. Over the past two decades, the prevalence of autism spectrum disorders has progressively increased, however, no clear diagnostic markers and specifically targeted medications for autism have emerged. As a result, neurobehavioral abnormalities, neurobiological alterations in ASD, and the development of novel ASD pharmacological therapy necessitate multidisciplinary collaboration. In this review, we discuss the development of multiple animal models of ASD to contribute to the disease mechanisms of ASD, as well as new studies from multiple disciplines to assess the behavioral pathology of ASD. In addition, we summarize and highlight the mechanistic advances regarding gene transcription, RNA and non-coding RNA translation, abnormal synaptic signaling pathways, epigenetic post-translational modifications, brain-gut axis, immune inflammation and neural loop abnormalities in autism to provide a theoretical basis for the next step of precision therapy. Furthermore, we review existing autism therapy tactics and limits and present challenges and opportunities for translating multidisciplinary knowledge of ASD into clinical practice.

Reversibility and therapeutic development for neurodevelopmental disorders, insights from genetic animal models

Neurodevelopmental Disorders (NDDs) encompass a broad spectrum of conditions resulting from atypical brain development. Over the past decades, we have had the fortune to witness enormous progress in diagnosis, etiology discovery, modeling, and mechanistic understanding of NDDs from both fundamental and clinical research. Here, we review recent neurobiological advances from experimental models of NDDs. We introduce several examples and highlight breakthroughs in reversal studies of phenotypes using genetically engineered models of NDDs. The in-depth understanding of brain pathophysiology underlying NDDs and evaluations of reversibility in animal models paves the foundation for discovering novel treatment options. We discuss how the expanding property of cutting-edge technologies, such as gene editing and AAV-mediated gene delivery, are leveraged in animal models for the therapeutic development of NDDs. We envision opportunities and challenges toward faithful modeling and fruitful clinical translation.

SHANK1 facilitates non-small cell lung cancer processes through modulating the ubiquitination of Klotho by interacting with MDM2

SH3 and multiple ankyrin repeat domains 1 (SHANK1) is a scaffold protein, plays an important role in the normal function of neuron system. It has recently been shown to be a potential oncogene. In the present study, we report that the expression of SHANK1 is upregulated in non-small cell lung cancer (NSCLC), and is correlated with clinic pathological characteristics of NSCLC. Moreover, SHANK1 overexpression enhances the proliferation, migration and invasion of NSCLC cells. Mouse cell-derived xenograft model also confirmed the effects of SHANK1 on tumor growth in vivo. Furthermore, we found that SHANK1 increases the protein degradation of Klotho (KL), an important tumor suppressor, through ubiquitination-dependent pathway. In particular, we report discovery of KL as a SHANK1-interacting protein that acts as a new substate of the E3 ubiquitin ligase MDM2. SHANK1 can form a complex with KL and MDM2 and enhance the interaction between KL and MDM2. Our findings reveal an important oncogenic role and mechanism of SHANK1, suggesting SHANK1 can be a potential therapeutic target in NSCLC.