A pilot controlled trial of insulin-like growth factor-1 in children with Phelan-McDermid syndrome

Insulin-Like Growth Factor 1 Has the Potential to Be Used as a Diagnostic Tool and Treatment Target for Autism Spectrum Disorders

Autism spectrum disorder (ASD), a heterogeneous group of neurodevelopmental disorders, is characterized by social impairment and repetitive and stereotypic behaviors. Because of the lack of approved laboratory diagnostic markers and effective therapeutic medications, it is one of the most challenging diseases. Therefore, it is urgent to explore potential diagnosis markers or therapeutic targets. Insulin-like growth factor 1 (IGF-1) is a neurotrophic growth factor that enhances brain development. IGF-1 levels in body fluids are lower in preschool children with ASD than in typically developing children, which may serve as a potential diagnostic marker. In various ASD models associated with genetic or environmental exposure, IGF-1 treatment can improve core symptoms or pathological changes, including neuronal development, neural cell survival, balance of synaptic excitation and inhibition, neuroimmunology, and oxidative stress status. In March 2023 an IGF-1 derivative was approved as the first drug for treating Rett syndrome, an ASD-related neurodevelopmental disorder, to improve fundamental symptoms such as social communication. Thus, in this review, we present accumulating evidence of altered IGF-1 levels in ASD patients and the possible mechanisms, as well as evidence that IGF-1 treatment improves the pathophysiology in various ASD models. IGF-1 has the potential to be an early diagnosis marker and an effective therapeutic for ASD.

A role for astrocytic insulin-like growth factor I receptors in the response to ischemic insult

Increased neurotrophic support, including insulin-like growth factor I (IGF-I), is an important aspect of the adaptive response to ischemic insult. However, recent findings indicate that the IGF-I receptor (IGF-IR) in neurons plays a detrimental role in the response to stroke. Thus, we investigated the role of astrocytic IGF-IR on ischemic insults using tamoxifen-regulated Cre deletion of IGF-IR in glial fibrillary acidic protein (GFAP) astrocytes, a major cellular component in the response to injury. Ablation of IGF-IR in astrocytes (GFAP-IGF-IR KO mice) resulted in larger ischemic lesions, greater blood-brain-barrier disruption and more deteriorated sensorimotor coordination. RNAseq detected increases in inflammatory, cell adhesion and angiogenic pathways, while the expression of various classical biomarkers of response to ischemic lesion were significantly increased at the lesion site compared to control littermates. While serum IGF-I levels after injury were decreased in both control and GFAP-IR KO mice, brain IGF-I mRNA expression show larger increases in the latter. Further, greater damage was also accompanied by altered glial reactivity as reflected by changes in the morphology of GFAP astrocytes, and relative abundance of ionized calcium binding adaptor molecule 1 (Iba 1) microglia. These results suggest a protective role for astrocytic IGF-IR in the response to ischemic injury.

Caregiver perspectives on patient-focused drug development for Phelan-McDermid syndrome

BACKGROUND

Phelan-McDermid syndrome (PMS) is a neurodevelopmental disorder caused by SHANK3 haploinsufficiency with clinical manifestations that can be devastating and profoundly affect quality of life.

RESULTS

The Externally Led Patient-Focused Drug Development (EL-PFDD) meeting was an opportunity for families affected by PMS to share with the Food and Drug Administration (FDA) how symptoms impact their lives and how treatments could be most meaningful. The Voice of the Patient report serves as a summary of this meeting to influence upcoming drug development and clinical trials. The purpose of this report is to provide a clinical perspective on the results of the EL-PFDD meeting to amplify the voice of these caregivers to the scientific community.

CONCLUSIONS

Caregivers prioritize an improved quality of life for their loved ones characterized by improved cognitive function, improved communication, increased independence, and reduced risk of regression. With these caregiver priorities in mind, this report provides the FDA and the scientific community with a clear understanding of which aspects of PMS should influence the development of future therapeutics.

Association between serum insulin-like growth factor 1 levels and the improvements of cognitive impairments in a subgroup of schizophrenia: Preliminary findings

BACKGROUND

Numerous studies have implicated abnormal insulin-like growth factor 1 (IGF-1) in the pathophysiology of schizophrenia, but findings have been inconsistent.

METHODS

We conducted a meta-analysis to compare IGF-1 levels in schizophrenia patients with healthy controls and explored factors contributing to variability between estimates. In an independent sample (58 chronic schizophrenia patients and 30 healthy controls), we investigated differences in IGF-1 levels among schizophrenia subgroups with distinct cognitive profiles, identified using k-means clustering based on five cognitive domains from The Repeatable Battery for the Assessment of Neuropsychological Status. Associations between serum IGF-1 levels and clinical and neurocognitive improvements were also examined.

RESULTS

The meta-analysis revealed significantly lower serum IGF-1 levels in schizophrenia patients compared to healthy controls, albeit with high heterogeneity. Medication status, BMI, and severity of negative symptoms were identified as potential contributors to this heterogeneity. In our independent study, antipsychotic treatment led to a significant increase in IGF-1 levels, and lower pre-treatment serum IGF-1 levels correlated with greater improvement in cognitive deficits, particularly in a subgroup with more severe cognitive symptoms.

CONCLUSIONS

Our findings support the "IGF-1 deficiency hypothesis" in the pathogenesis of schizophrenia. Further research is crucial to elucidate the role of IGF-1 in the cognitive impairments associated with schizophrenia.

The role of insulin/IGF1 signalling in neurodevelopmental and neuropsychiatric disorders - Evidence from human neuronal cell models

Insulin and insulin-like growth factor 1 (IGF1) signalling play a central role in the development and maintenance of neurons in the brain, and human neurodevelopmental as well as neuropsychiatric disorders have been linked to impaired insulin and IGF1 signalling. This review focuses on the impairments of the insulin and IGF1 signalling cascade in the context of neurodevelopmental and neuropsychiatric disorders, based on evidence from human neuronal cell models. Clear evidence was obtained for impaired insulin and IGF1 receptor downstream signalling in neurodevelopmental disorders, while the evidence for its role in neuropsychiatric disorders was less substantial. Human neuronal model systems can greatly add to our knowledge about insulin/IGF1 signalling in the brain, its role in restoring dendritic maturity, and complement results from clinical studies and animal models. Moreover, they represent a useful model for the development of new therapeutic strategies. Further research is needed to systematically investigate the exact role of the insulin/IGF1 signalling cascades in neurodevelopmental and neuropsychiatric disorders, and to elucidate the respective therapeutic implications.

Sleep disturbances in Phelan-McDermid syndrome: Clinical and metabolic profiling of 56 individuals

Phelan-McDermid Syndrome (PMS) is caused by deletions at chromosome 22q13.3 or pathogenic/likely pathogenic SHANK3 variants. The clinical presentation is extremely variable and includes global developmental delay/intellectual disability (ID), seizures, neonatal hypotonia, and sleep disturbances, among others. This study investigated the prevalence of sleep disturbances, and the genetic and metabolic features associated with them, in a cohort of 56 individuals with PMS. Sleep data were collected via standardized observer/caregiver questionnaires, while genetic data from array-CGH and sequencing of 9 candidate genes within the 22q13.3 region, and metabolic profiling utilized the Biolog Phenotype Mammalian MicroArray plates. Sleep disturbances were present in 64.3% of individuals with PMS, with the most common problem being waking during the night (39%). Sleep disturbances were more prevalent in individuals with a SHANK3 pathogenic variant (89%) compared to subjects with 22q13.3 deletions of any size (59.6%). Distinct metabolic profiles for individuals with PMS with and without sleep disturbances were also identified. These data are helpful information for recognizing and managing sleep disturbances in individuals with PMS, outlining the main candidate gene for this neurological manifestation, and highlighting potential biomarkers for early identification of at-risk subjects and molecular targets for novel treatment approaches.

Updated consensus guidelines on the management of Phelan-McDermid syndrome

Phelan-McDermid syndrome (PMS) is a genetic condition caused by SHANK3 haploinsufficiency and characterized by a wide range of neurodevelopmental and systemic manifestations. The first practice parameters for assessment and monitoring in individuals with PMS were published in 2014; recently, knowledge about PMS has grown significantly based on data from longitudinal phenotyping studies and large-scale genotype-phenotype investigations. The objective of these updated clinical management guidelines was to: (1) reflect the latest in knowledge in PMS and (2) provide guidance for clinicians, researchers, and the general community. A taskforce was established with clinical experts in PMS and representatives from the parent community. Experts joined subgroups based on their areas of specialty, including genetics, neurology, neurodevelopment, gastroenterology, primary care, physiatry, nephrology, endocrinology, cardiology, gynecology, and dentistry. Taskforce members convened regularly between 2021 and 2022 and produced specialty-specific guidelines based on iterative feedback and discussion. Taskforce leaders then established consensus within their respective specialty group and harmonized the guidelines. The knowledge gained over the past decade allows for improved guidelines to assess and monitor individuals with PMS. Since there is limited evidence specific to PMS, intervention mostly follows general guidelines for treating individuals with developmental disorders. Significant evidence has been amassed to guide the management of comorbid neuropsychiatric conditions in PMS, albeit mainly from caregiver report and the experience of clinical experts. These updated consensus guidelines on the management of PMS represent an advance for the field and will improve care in the community. Several areas for future research are also highlighted and will contribute to subsequent updates with more refined and specific recommendations as new knowledge accumulates.

Definition and clinical variability of SHANK3-related Phelan-McDermid syndrome

Phelan-McDermid syndrome (PMS) is an infrequently described syndrome that presents with a disturbed development, neurological and psychiatric characteristics, and sometimes other comorbidities. As part of the development of European medical guidelines we studied the definition, phenotype, genotype-phenotype characteristics, and natural history of the syndrome. The number of confirmed diagnoses of PMS in different European countries was also assessed and it could be concluded that PMS is underdiagnosed. The incidence of PMS in European countries is estimated to be at least 1 in 30,000. Next generation sequencing, including analysis of copy number variations, as first tier in diagnostics of individuals with intellectual disability will likely yield a larger number of individuals with PMS than presently known. A definition of PMS by its phenotype is at the present not possible, and therefore PMS-SHANK3 related is defined by the presence of SHANK3 haploinsufficiency, either by a deletion involving region 22q13.2-33 or a pathogenic/likely pathogenic variant in SHANK3. In summarizing the phenotype, we subdivided it into that of individuals with a 22q13 deletion and that of those with a pathogenic/likely pathogenic SHANK3 variant. The phenotype of individuals with PMS is variable, depending in part on the deletion size or, whether only a variant of SHANK3 is present. The core phenotype in the domains development, neurology, and senses are similar in those with deletions and SHANK3 variants, but individuals with a SHANK3 variant more often are reported to have behavioural disorders and less often urogenital malformations and lymphedema. The behavioural disorders may, however, be a less outstanding feature in individuals with deletions accompanied by more severe intellectual disability. Data available on the natural history are limited. Results of clinical trials using insulin-like growth factor I (IGF-1), intranasal insulin, and oxytocin are available, other trials are in progress. The present guidelines for PMS aim at offering tools to caregivers and families to provide optimal care to individuals with PMS.

Stratification of a Phelan-McDermid Syndrome Population Based on Their Response to Human Growth Hormone and Insulin-like Growth Factor

Phelan-McDermid syndrome (PMS), caused by pathogenic variants in the SHANK3 gene or 22q13 deletions, is characterized by intellectual disability, autistic features, developmental delays, and neonatal hypotonia. Insulin-like growth factor 1 (IGF-1) and human growth hormone (hGH) have been shown to reverse neurobehavioral deficits in PMS. We assessed the metabolic profiling of 48 individuals with PMS and 50 controls and determined subpopulations by taking the top and bottom 25% of responders to hGH and IGF-1. A distinct metabolic profile for individuals with PMS showed a reduced ability to metabolize major energy sources and a higher metabolism of alternative energy sources. The analysis of the metabolic response to hGH or IGF-1 highlighted a major overlap between both high and low responders, validating the model and suggesting that the two growth factors share many target pathways. When we investigated the effect of hGH and IGF-1 on the metabolism of glucose, the correlation between the high-responder subgroups showed less similarity, whereas the low-responders were still relatively similar. Classification of individuals with PMS into subgroups based on responses to a compound can allow an investigation into pathogenic mechanisms, the identification of molecular biomarkers, an exploration of in vitro responses to candidate drugs, and eventually the selection of better candidates for clinical trials.

Elevation of SHANK3 Levels by Antisense Oligonucleotides Directed Against the 3'-UTR of the Human SHANK3 mRNA

SHANK3 is a member of the SHANK family of scaffolding proteins that localize to the postsynaptic density of excitatory synapses. Mutations within the SHANK3 gene or SHANK3 haploinsufficiency is thought to be one of the major causes for Phelan-McDermid Syndrome (PMDS) that is characterized by a broad spectrum of autism-related behavioral alterations. Several approaches have already been proposed to elevate SHANK3 protein levels in PMDS patients like transcriptional activation or inhibition of SHANK3 degradation. We undertook a systematic screening approach and tested whether defined antisense oligonucleotides (ASOs) directed against the 3' untranslated region (3'-UTR) of the human SHANK3 mRNA are suitable to elevate SHANK3 protein levels. Using human induced pluripotent stem cells (hiPSCs) and hiPSCs-derived motoneurons from controls and PMDS patients we eventually identified two 18 nucleotide ASOs (ASO 4-5.2-4 and 4-5.2-6) that were able to increase SHANK3 protein levels in vitro by about 1.3- to 1.6-fold. These findings were confirmed by co-transfection of the identified ASOs with a GFP-SHANK3-3'-UTR construct in HEK293T cells using GFP protein expression as read-out. Based on these results we propose a novel approach to elevate SHANK3 protein concentrations by 3'-UTR specific ASOs. Further research is needed to test the suitability of SHANK3-specific ASOs as pharmacological compounds also in vivo.

Autistic Traits in the Neurotypical Chinese Population: A Chinese Version of Glasgow Sensory Questionnaire and a Cross-Cultural Difference in Attention-to-Detail

The aim of this study was to assess cross-cultural differences in autistic traits relating to sensory sensitivity/attention-to-detail versus socio-communicative problems in a Chinese sample. A measure of atypical sensory sensitivity (Glasgow Sensory Questionnaire, GSQ) was translated into Chinese and compared against another measure of autistic traits (Chinese version of Autism Quotient, AQ). A second Chinese sample was administered English-language versions. We show that the translated GSQ has: good internal reliability; a similar profile of item responses to the English version; and a significant correlation with the AQ. Secondly we report an unexpected, but replicable, finding amongst the Chinese. Specifically, attention-to-detail was negatively correlated with socio-communicative difficulties (whereas in Western samples it is the reverse).

Large 22q13.3 deletions perturb peripheral transcriptomic and metabolomic profiles in Phelan-McDermid syndrome

Phelan-McDermid syndrome (PMS) is a rare neurodevelopmental disorder caused at least in part by haploinsufficiency of the SHANK3 gene, due to sequence variants in SHANK3 or subtelomeric 22q13.3 deletions. Phenotypic differences have been reported between PMS participants carrying small "class I" mutations and large "class II" mutations; however, the molecular perturbations underlying these divergent phenotypes remain obscure. Using peripheral blood transcriptome and serum metabolome profiling, we examined the molecular perturbations in the peripheral circulation associated with a full spectrum of PMS genotypes spanning class I (n = 37) and class II mutations (n = 39). Transcriptomic data revealed 52 genes with blood expression profiles that tightly scale with 22q.13.3 deletion size. Furthermore, we uncover 208 underexpressed genes in PMS participants with class II mutations, which were unchanged in class I mutations. These genes were not linked to 22q13.3 and were strongly enriched for glycosphingolipid metabolism, NCAM1 interactions, and cytotoxic natural killer (NK) immune cell signatures. In silico predictions estimated a reduction in CD56+ CD16- NK cell proportions in class II mutations, which was validated by mass cytometry time of flight. Global metabolomics profiling identified 24 metabolites that were significantly altered in PMS participants with class II mutations and confirmed a general reduction in sphingolipid metabolism. Collectively, these results provide new evidence linking PMS participants carrying class II mutations with decreased expression of cytotoxic cell signatures, reduced relative proportions of NK cells, and lower sphingolipid metabolism. These findings highlight alternative avenues for therapeutic development and offer new mechanistic insights supporting genotype-to-phenotype associations in PMS.

[Phelan-McDermid syndrome associated with a novel heterozygous mutation in the SHANK3 gene]

Phelan-McDermid syndrome (PMS) is a hereditary disorder associated with microdeletions of chromosome 22q13 or point mutations in SHANK3, characterized by mental and speech delays, intellectual disability, epilepsy and autism spectrum disorder. We describe a case PMS associated with a heterozygous mutation c.2486delC (p.Pro829fs) in SHANK3. The diagnostic pathway of a female patient with PMS took more than 7 years; the reason for treatment was the onset of epileptic seizures and impaired speech development. The existence of different types of rearrangements and genomic variations can explain the high clinical variability observed in individuals with PMS. Only molecular diagnosis can accurately diagnose individuals with PMS for follow-up and medical genetic counselling of families.

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.

Intranasal Peptide Therapeutics: A Promising Avenue for Overcoming the Challenges of Traditional CNS Drug Development

The central nervous system (CNS) has, among all organ systems in the human body, the highest failure rate of traditional small-molecule drug development, ranging from 80-100% depending on the area of disease research. This has led to widespread abandonment by the pharmaceutical industry of research and development for CNS disorders, despite increased diagnoses of neurodegenerative disorders and the continued lack of adequate treatment options for brain injuries, stroke, neurodevelopmental disorders, and neuropsychiatric illness. However, new approaches, concurrent with the development of sophisticated bioinformatic and genomic tools, are being used to explore peptide-based therapeutics to manipulate endogenous pathways and targets, including "undruggable" intracellular protein-protein interactions (PPIs). The development of peptide-based therapeutics was previously rejected due to systemic off-target effects and poor bioavailability arising from traditional oral and systemic delivery methods. However, targeted nose-to-brain, or intranasal (IN), approaches have begun to emerge that allow CNS-specific delivery of therapeutics via the trigeminal and olfactory nerve pathways, laying the foundation for improved alternatives to systemic drug delivery. Here we review a dozen promising IN peptide therapeutics in preclinical and clinical development for neurodegenerative (Alzheimer's, Parkinson's), neuropsychiatric (depression, PTSD, schizophrenia), and neurodevelopmental disorders (autism), with insulin, NAP (davunetide), IGF-1, PACAP, NPY, oxytocin, and GLP-1 agonists prominent among them.

Hyperbaric Oxygen Therapy Alleviates Social Behavior Dysfunction and Neuroinflammation in a Mouse Model for Autism Spectrum Disorders

Autism spectrum disorder (ASD) is a multifactorial neurodevelopmental disorder (NDD) characterized by impaired social communication and repetitive behavior, among other symptoms. ASD is highly heritable, with SHANK3 being one of the high-risk genes for ASD. In recent years, knowledge has been growing regarding the neuroplasticity effect induced by hyperbaric oxygen therapy (HBOT) and its potential use for ASD. Here, we characterized the effect of HBOT on a mouse model for ASD with the human genetic condition of InsG3680 mutation in the Shank3 gene. As compared to placebo, HBOT improved social behavior and reduced neuroinflammation in the cortex of the InsG3680(+/+) mice. Specifically, HBOT induced upregulation of Insulin-like growth factor 1 (Igf1) expression levels and reduced the number of Iba1-positive cells in the mouse model for ASD compared to placebo control. Together, our research suggests that HBOT has the potential to improve the clinical outcome of ASD by ameliorating some of the core pathophysiological processes responsible for the development of the disorder.

Signalling pathways in autism spectrum disorder: mechanisms and therapeutic implications

Autism spectrum disorder (ASD) is a prevalent and complex neurodevelopmental disorder which has strong genetic basis. Despite the rapidly rising incidence of autism, little is known about its aetiology, risk factors, and disease progression. There are currently neither validated biomarkers for diagnostic screening nor specific medication for autism. Over the last two decades, there have been remarkable advances in genetics, with hundreds of genes identified and validated as being associated with a high risk for autism. The convergence of neuroscience methods is becoming more widely recognized for its significance in elucidating the pathological mechanisms of autism. Efforts have been devoted to exploring the behavioural functions, key pathological mechanisms and potential treatments of autism. Here, as we highlight in this review, emerging evidence shows that signal transduction molecular events are involved in pathological processes such as transcription, translation, synaptic transmission, epigenetics and immunoinflammatory responses. This involvement has important implications for the discovery of precise molecular targets for autism. Moreover, we review recent insights into the mechanisms and clinical implications of signal transduction in autism from molecular, cellular, neural circuit, and neurobehavioural aspects. Finally, the challenges and future perspectives are discussed with regard to novel strategies predicated on the biological features of autism.

A Role for Insulin-like Growth Factor 1 in the Generation of Epileptic Spasms in a murine model

OBJECTIVE

Infantile spasms are associated with a wide variety of clinical conditions, including perinatal brain injuries. We have created a model in which prolonged infusion of tetrodotoxin (TTX) into the neocortex, beginning in infancy, produces a localized lesion and reproduces the behavioral spasms, electroencephalogram (EEG) abnormalities, and drug responsiveness seen clinically. Here, we undertook experiments to explore the possibility that the growth factor IGF-1 plays a role in generating epileptic spasms.

METHODS

We combined long-term video EEG recordings with quantitative immunohistochemical and biochemical analyses to unravel IGF-1's role in spasm generation. Immunohistochemistry was undertaken in surgically resected tissue from infantile spasms patients. We used viral injections in neonatal conditional IGF-1R knock-out mice to show that an IGF-1-derived tripeptide (1-3)IGF-1, acts through the IGF-1 receptor to abolish spasms.

RESULTS

Immunohistochemical methods revealed widespread loss of IGF-1 from cortical neurons, but an increase in IGF-1 in the reactive astrocytes in the TTX-induced lesion. Very similar changes were observed in the neocortex from patients with spasms. In animals, we observed reduced signaling through the IGF-1 growth pathways in areas remote from the lesion. To show the reduction in IGF-1 expression plays a role in spasm generation, epileptic rats were treated with (1-3)IGF-1. We provide 3 lines of evidence that (1-3)IGF-1 activates the IGF-1 signaling pathway by acting through the receptor for IGF-1. Treatment with (1-3)IGF-1 abolished spasms and hypsarrhythmia-like activity in the majority of animals.

INTERPRETATION

Results implicate IGF-1 in the pathogenesis of infantile spasms and IGF-1 analogues as potential novel therapies for this neurodevelopmental disorder. ANN NEUROL 2022;92:45-60.

Gene-Modified Stem Cells for Spinal Cord Injury: a Promising Better Alternative Therapy

Stem cell therapy holds great promise for the treatment of spinal cord injury (SCI), which can reverse neurodegeneration and promote tissue regeneration via its pluripotency and ability to secrete neurotrophic factors. Although various stem cell-based approaches have shown certain therapeutic effects when applied to the treatment of SCI, their clinical efficacies have been disappointing. Thus, it is an urgent need to further enhance the neurological benefits of stem cells through bioengineering strategies including genetic engineering. In this review, we summarize the progress of stem cell therapy for SCI and the prospect of genetically modified stem cells, focusing on the genome editing tools and functional molecules involved in SCI repair, trying to provide a deeper understanding of genetically modified stem cell therapy and more applicable clinical strategies for SCI repair.

Clinical trial of insulin-like growth factor-1 in Phelan-McDermid syndrome

Background

Phelan-McDermid syndrome (PMS) is caused by haploinsufficiency of the SHANK3 gene and is characterized by global developmental delays and autism spectrum disorder (ASD). Based on several converging lines of preclinical and clinical evidence supporting the use of insulin-like growth factor-1 (IGF-1) in PMS, this study aims to follow-up a previous pilot study with IGF-1 to further evaluate this novel therapeutic for core symptoms of ASD in children with PMS.

Methods

Ten children aged 5–9 with PMS were enrolled. Participants were randomized to receive IGF-1 or placebo (saline) using a 12-week, double-blind, crossover design. Efficacy was assessed using the primary outcome of the Aberrant Behavior Checklist—Social Withdrawal (ABC-SW) subscale as well as secondary outcome measures reflecting core symptoms of ASD. To increase power and sample size, we jointly analyzed the effect of IGF-1 reported here together with results from our previous controlled trail of IGF-1 in children with PMS (combined N = 19).

Results

Results on the ABC-SW did not reach statistical significance, however significant improvements in sensory reactivity symptoms were observed. In our pooled analyses, IGF-1 treatment also led to significant improvements in repetitive behaviors and hyperactivity. There were no other statistically significant effects seen across other clinical outcome measures. IGF-1 was well tolerated and there were no serious adverse events.

Limitations

The small sample size and expectancy bias due to relying on parent reported outcome measures may contribute to limitations in interpreting results.

Conclusion

IGF-1 is efficacious in improving sensory reactivity symptoms, repetitive behaviors, and hyperactivity  in children with PMS.

Trial registration NCT01525901.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-022-00493-7.

Repetitive Restricted Behaviors in Autism Spectrum Disorder: From Mechanism to Development of Therapeutics

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by deficits in social communication, social interaction, and repetitive restricted behaviors (RRBs). It is usually detected in early childhood. RRBs are behavioral patterns characterized by repetition, inflexibility, invariance, inappropriateness, and frequent lack of obvious function or specific purpose. To date, the classification of RRBs is contentious. Understanding the potential mechanisms of RRBs in children with ASD, such as neural connectivity disorders and abnormal immune functions, will contribute to finding new therapeutic targets. Although behavioral intervention remains the most effective and safe strategy for RRBs treatment, some promising drugs and new treatment options (e.g., supplementary and cell therapy) have shown positive effects on RRBs in recent studies. In this review, we summarize the latest advances of RRBs from mechanistic to therapeutic approaches and propose potential future directions in research on RRBs.

Maternal Duplication 15q11-13 Syndrome with Autism Spectrum Disorder: Mood Stabilization by Carbamazepine

Objectives: Maternal 15q11-13 duplication syndrome (dup15q) is one of the most frequently observed and penetrant genetic abnormalities associated with autism spectrum disorder (ASD), and commonly presents with psychiatric symptoms and seizures. Although carbamazepine has been reported as effective in managing comorbid seizures in dup15q, it has not been reported to be used as a mood stabilizer in this population. Methods: We retrospectively reviewed the charts of five consecutive patients presenting with previously diagnosed dup15q and ASD seeking treatment for psychiatric symptoms and, in four of the patients, seizures. These were the only patients with dup15q treated with carbamazepine in the Neurodevelopmental Psychopharmacology Clinic at the University of Illinois at Chicago during the review period. Results: During treatment, carbamazepine was found to be more effective than other mood stabilizers in all five patients, and in one case a better antiepileptic. Symptoms consistent with bipolar mood disorder such as hyperactivity, impulsivity, irritability, mood lability, intrusiveness, and pressured speech were improved with carbamazepine in combination with other psychotropic medications. This improvement was greater than with other mood stabilizers, including oxcarbazepine, valproate, and lamotrigine. In one case, valproate paradoxically worsened symptoms. In three cases, anxiety was improved with carbamazepine when used in conjunction with other medications targeting anxiety. Conclusions: In treating five patients with dup15q, carbamazepine more effectively stabilized mood-related symptoms than alternative treatments. Prospective randomized controlled trials are necessary to confirm this observation.

Novel treatments in autism spectrum disorder

PURPOSE OF REVIEW

There are currently no approved medications for the core symptoms of autism spectrum disorder (ASD), and only limited data on the management of co-occurring mental health and behavioural symptoms. The purpose of this review is to synthesize recent trials on novel treatments in ASD, with a focus on research trends in the past 2 years.

RECENT FINDINGS

No new pharmacologic agents received regulatory approval for use in ASD. Several large randomized controlled trials (RCTs) had negative or ambiguous results (e.g. fluoxetine, oxytocin). A cross-over RCT of an oral cannabinoid suggested possible benefits for disruptive behaviours. Two large-scale multicentre trials of bumetanide were terminated early for lack of efficacy. Multicenter trials using repetitive transcranial magnetic stimulation are underway. Recent meta-analyses indicate that specific behavioural and psychological interventions can support social communication and treat anxiety. Numerous novel treatment targets informed by biological mechanisms are under investigation.

SUMMARY

Recent data support the use of behavioural and psychological interventions for social communication and anxiety in ASD; data are more limited regarding pharmacotherapy for core and associated symptoms. Next steps include replication of early findings, trials of new molecular targets, and the identification of novel biomarkers, including genetic predictors, of treatment response.

Research Progress on Neuroprotection of Insulin-like Growth Factor-1 towards Glutamate-Induced Neurotoxicity

Insulin-like growth factor-1 (IGF-1) and its binding proteins and receptors are widely expressed in the central nervous system (CNS), proposing IGF-1-induced neurotrophic actions in normal growth, development, and maintenance. However, while there is convincing evidence that the IGF-1 system has specific endocrine roles in the CNS, the concept is emerging that IGF-I might be also important in disorders such as ischemic stroke, brain trauma, Alzheimer’s disease, epilepsy, etc., by inducing neuroprotective effects towards glutamate-mediated excitotoxic signaling pathways. Research in rodent models has demonstrated rescue of pathophysiological and behavioral abnormalities when IGF-1 was administered by different routes, and several clinical studies have shown safety and promise of efficacy in neurological disorders of the CNS. Focusing on the relationship between IGF-1-induced neuroprotection and glutamate-induced excitatory neurotoxicity, this review addresses the research progress in the field, intending to provide a rationale for using IGF-I clinically to confer neuroprotective therapy towards neurological diseases with glutamate excitotoxicity as a common pathological pathway.

A proof-of-concept study of growth hormone in children with Phelan–McDermid syndrome

Background

Phelan–McDermid syndrome (PMS) is caused by 22q13 deletions including SHANK3 or pathogenic sequence variants in SHANK3 and is among the more common rare genetic findings in autism spectrum disorder (ASD). SHANK3 is critical for synaptic function, and preclinical and clinical studies suggest that insulin-like growth factor-1 (IGF-1) can reverse a range of deficits in PMS. IGF-1 release is stimulated by growth hormone secretion from the anterior pituitary gland, and this study sought to assess the feasibility of increasing IGF-1 levels through recombinant human growth hormone (rhGH) treatment, in addition to establishing safety and exploring efficacy of rhGH in children with PMS.

Methods

rhGH was administered once daily for 12 weeks to six children with PMS using an open-label design. IGF-1 levels, safety, and efficacy assessments were measured every 4 weeks throughout the study.

Results

rhGH administration increased levels of IGF-1 by at least 2 standard deviations and was well tolerated without serious adverse events. rhGH treatment was also associated with clinical improvement in social withdrawal, hyperactivity, and sensory symptoms.

Limitations

Results should be interpreted with caution given the small sample size and lack of a placebo control.

Conclusions

Overall, findings are promising and indicate the need for larger studies with rhGH in PMS.

Trial registration NCT04003207. Registered July 1, 2019, https://clinicaltrials.gov/ct2/show/NCT04003207.

Effectiveness of Recombinant Human Growth Hormone Therapy for Children With Phelan-McDermid Syndrome: An Open-Label, Cross-Over, Preliminary Study

BACKGROUND

Phelan-McDermid syndrome (PMS), also known as the 22q13. 3 deletion syndrome, is a rare neurodevelopmental syndrome with approximately 2,800 patients reported worldwide. Previous pilot study demonstrated that IGF-1 could significantly improve in both social impairment and restrictive behaviors of the patients. However, most of the patients in the developing countries like China cannot afford the high cost of using IGF-1. Our research team speculated that rhGH might serve as a low-cost and more accessible treatment for PMS. Therefore, the purpose of this open-label, cross-over, pilot study was to further investigate the safety and efficiency of rhGH in patients with PMS.

METHODS

A total of six children with PMS were enrolled in in this open-label, cross-over, pilot study. The children were randomly divided into two different groups. Group A received placebo followed by rhGH, while group B was treated with rhGH first. Neuropsychological and behavior assessments of the patients were performed before the stage I of study and 3 months after the intervention of stage I. After a 4-week period of washout, these assessments were conducted again before the stage II of study and 3 months after the intervention of stage II. Serum insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding-protein (IGFBP)-3 were also evaluated monthly during the intervention phases of the pilot study.

RESULTS

Compared with the placebo, rhGH treatment significantly decreased subscale scores of GDS (P < 0.0085) and trended to improve the total scores of GDS (P < 0.05), while the total scores and subscale scores of SC-ABC significantly decreased (P < 0.0085) following 3-months rhGH treatment. The similar results were also observed in comparison with baseline. Compared with the baseline, the level of serum IGF-1 and IGFBP-3 increased significantly (P < 0.05) following 3-months rhGH treatment, while the placebo group had no significant impact on serum IGF-1 and IGFBP-3 (P > 0.05). One child developed skin allergy the day after the first rhGH treatment, which were resolved later.

CONCLUSIONS

In summary, this pilot study involving six PMS children patients reveals that rhGH has a positive treatment effect on PMS. These results encourage the undertaking of a large, randomized placebo-controlled trial to conclusively prove rhGH efficacy and tolerability in PMS, thereby promoting it as a low-cost, more accessible treatment for PMS, as compared to IGF-1.

Case Report: The Emerging Role of Ring Chromosome 22 in Phelan-McDermid Syndrome With Atypical Teratoid/Rhabdoid Tumor: The First Child Treated With Growth Hormone

Atypical teratoid/rhabdoid tumors (AT/RTs) in the rhabdoid tumor predisposition syndromes are most often caused by germline mutations of the SMARCB1 gene located in chromosome 22q11.2. Although rarely, it can also result from the constitutional ring chromosome 22 (r22): during mitosis the ring chromosome may lead to an increased rate of somatic mutations, resulting in rhabdoid tumor predispositions when the tumor-suppressor gene SMARCB1 is involved. Individuals with r22 may present similar features as those with Phelan-McDermid syndrome (PMDS) due to 22q13.3 deletion, including the SHANK3 gene. Despite several reports on AT/RT in children with r22 and/or PMDS have been published, the role of constitutional r22 as new oncogenic mechanism for AT/RT is still under investigation. There is not a lot of data available on therapeutic and prognostic implications of r22 in AT/RT and PMDS. Herein, we present the first case of a child with constitutional r22, PMDS and AT/RT of the brain, who is a long term survivor and is been treated with growth hormone. We also describe an unexpected adverse reaction to midazolam.

Comparison of SHANK3 deficiency in animal models: phenotypes, treatment strategies, and translational implications

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental condition, which is characterized by clinical heterogeneity and high heritability. Core symptoms of ASD include deficits in social communication and interaction, as well as restricted, repetitive patterns of behavior, interests, or activities. Many genes have been identified that are associated with an increased risk for ASD. Proteins encoded by these ASD risk genes are often involved in processes related to fetal brain development, chromatin modification and regulation of gene expression in general, as well as the structural and functional integrity of synapses. Genes of the SH3 and multiple ankyrin repeat domains (SHANK) family encode crucial scaffolding proteins (SHANK1-3) of excitatory synapses and other macromolecular complexes. SHANK gene mutations are highly associated with ASD and more specifically the Phelan-McDermid syndrome (PMDS), which is caused by heterozygous 22q13.3-deletion resulting in SHANK3-haploinsufficiency, or by SHANK3 missense variants. SHANK3 deficiency and potential treatment options have been extensively studied in animal models, especially in mice, but also in rats and non-human primates. However, few of the proposed therapeutic strategies have translated into clinical practice yet.

MAIN TEXT

This review summarizes the literature concerning SHANK3-deficient animal models. In particular, the structural, behavioral, and neurological abnormalities are described and compared, providing a broad and comprehensive overview. Additionally, the underlying pathophysiologies and possible treatments that have been investigated in these models are discussed and evaluated with respect to their effect on ASD- or PMDS-associated phenotypes.

CONCLUSIONS

Animal models of SHANK3 deficiency generated by various genetic strategies, which determine the composition of the residual SHANK3-isoforms and affected cell types, show phenotypes resembling ASD and PMDS. The phenotypic heterogeneity across multiple models and studies resembles the variation of clinical severity in human ASD and PMDS patients. Multiple therapeutic strategies have been proposed and tested in animal models, which might lead to translational implications for human patients with ASD and/or PMDS. Future studies should explore the effects of new therapeutic approaches that target genetic haploinsufficiency, like CRISPR-mediated activation of promotors.

Insulin-like growth factor-2 does not improve behavioral deficits in mouse and rat models of Angelman Syndrome

BACKGROUND

Angelman Syndrome (AS) is a rare neurodevelopmental disorder for which there is currently no cure or effective therapeutic. Since the genetic cause of AS is known to be dysfunctional expression of the maternal allele of ubiquitin protein ligase E3A (UBE3A), several genetic animal models of AS have been developed. Both the Ube3a maternal deletion mouse and rat models of AS reliably demonstrate behavioral phenotypes of relevance to AS and therefore offer suitable in vivo systems in which to test potential therapeutics. One promising candidate treatment is insulin-like growth factor-2 (IGF-2), which has recently been shown to ameliorate behavioral deficits in the mouse model of AS and improve cognitive abilities across model systems.

METHODS

We used both the Ube3a maternal deletion mouse and rat models of AS to evaluate the ability of IGF-2 to improve electrophysiological and behavioral outcomes.

RESULTS

Acute systemic administration of IGF-2 had an effect on electrophysiological activity in the brain and on a metric of motor ability; however the effects were not enduring or extensive. Additional metrics of motor behavior, learning, ambulation, and coordination were unaffected and IGF-2 did not improve social communication, seizure threshold, or cognition.

LIMITATIONS

The generalizability of these results to humans is difficult to predict and it remains possible that dosing schemes (i.e., chronic or subchronic dosing), routes, and/or post-treatment intervals other than that used herein may show more efficacy.

CONCLUSIONS

Despite a few observed effects of IGF-2, our results taken together indicate that IGF-2 treatment does not profoundly improve behavioral deficits in mouse or rat models of AS. These findings shed cautionary light on the potential utility of acute systemic IGF-2 administration in the treatment of AS.

Criss-crossing autism spectrum disorder and adult neurogenesis

Autism spectrum disorder (ASD) comprises a group of multifactorial neurodevelopmental disorders primarily characterized by deficits in social interaction and repetitive behavior. Although the onset is typically in early childhood, ASD poses a lifelong challenge for both patients and caretakers. Adult neurogenesis (AN) is the process by which new functional neurons are created from neural stem cells existing in the post-natal brain. The entire event is based on a sequence of cellular processes, such as proliferation, specification of cell fate, maturation, and ultimately, synaptic integration into the existing neural circuits. Hence, AN is implicated in structural and functional brain plasticity throughout life. Accumulating evidence shows that impaired AN may underlie some of the abnormal behavioral phenotypes seen in ASD. In this review, we approach the interconnections between the molecular pathways related to AN and ASD. We also discuss existing therapeutic approaches targeting such pathways both in preclinical and clinical studies. A deeper understanding of how ASD and AN reciprocally affect one another could reveal important converging pathways leading to the emergence of psychiatric disorders.

The Neurological Manifestations of Phelan-McDermid Syndrome

Phelan-McDermid syndrome (PMS) is a genetic disorder, caused by haploinsufficiency of the SHANK3 gene on chromosome 22q13.3. PMS is characterized by neurobehavioral symptoms and signs including intellectual disability, speech and language impairment, autism spectrum disorder (ASD), hypotonia, and other motor abnormalities. In the brain, SHANK3 is expressed in neurons, especially in the synapse, and encodes a master scaffolding protein that forms a key framework in the postsynaptic density of glutamatergic synapses. Mutations in SHANK3 have also been identified in individuals with ASD, intellectual deficiency (ID), and schizophrenia. Shank3 deficient mice have defects in basal glutamatergic synaptic transmission in the hippocampus, and in synaptic transmission plasticity, including deficits in long-term potentiation, and show behavioral deficits compatible with the clinical manifestations of PMS. The PMS phenotype varies between affected individuals, but ID and speech and language impairment are present in all cases. ASD is present in a great majority of these individuals. Neurological examination demonstrates hypotonia and abnormalities of motor coordination, visual motor coordination, and gait in the majority of affected individuals. Sleep disturbances and increased pain tolerance are frequent parental complaints. Seizures and epilepsy are common, affecting more than 40% of individuals. Brain magnetic resonance imaging abnormalities include corpus callosum hypoplasia, delayed myelination and white matter abnormalities, dilated ventricles, and arachnoid cysts. Recent advanced imaging anatomic studies including diffusion tensor imaging, point to abnormal brain connectivity. The natural history of the syndrome is not yet fully known, but some individuals with PMS have a later onset of psychiatric illnesses including bipolar disease, accompanied by functional and neurological regression. Individuals with the syndrome are treated symptomatically. Advances in understanding the pathophysiology of this syndrome and the generation of animal models have raised opportunities for a biological cure for PMS. A pilot clinical trial with insulin-like growth factor-1 (IGF-1) showed positive effects on some behavioral core symptoms.

Genetic Findings as the Potential Basis of Personalized Pharmacotherapy in Phelan-McDermid Syndrome

Phelan-McDermid syndrome (PMS) is a genetic disorder often characterized by autism or autistic-like behavior. Most cases are associated with haploinsufficiency of the SHANK3 gene resulting from deletion of the gene at 22q13.3 or from a pathogenic variant in the gene. Treatment of PMS often targets SHANK3, yet deletion size varies from <50 kb to >9 Mb, potentially encompassing dozens of genes and disrupting regulatory elements altering gene expression, inferring the potential for multiple therapeutic targets. Repurposed drugs have been used in clinical trials investigating therapies for PMS: insulin-like growth factor 1 (IGF-1) for its effect on social and aberrant behaviors, intranasal insulin for improvements in cognitive and social ability, and lithium for reversing regression and stabilizing behavior. The pharmacogenomics of PMS is complicated by the CYP2D6 enzyme which metabolizes antidepressants and antipsychotics often used for treatment. The gene coding for CYP2D6 maps to 22q13.2 and is lost in individuals with deletions larger than 8 Mb. Because PMS has diverse neurological and medical symptoms, many concurrent medications may be prescribed, increasing the risk for adverse drug reactions. At present, there is no single best treatment for PMS. Approaches to therapy are necessarily complex and must target variable behavioral and physical symptoms of PMS.

Human neurons from Christianson syndrome iPSCs reveal mutation-specific responses to rescue strategies

Christianson syndrome (CS), an X-linked neurological disorder characterized by postnatal attenuation of brain growth (postnatal microcephaly), is caused by mutations in SLC9A6, the gene encoding endosomal Na⁺/H⁺ exchanger 6 (NHE6). To hasten treatment development, we established induced pluripotent stem cell (iPSC) lines from patients with CS representing a mutational spectrum, as well as biologically related and isogenic control lines. We demonstrated that pathogenic mutations lead to loss of protein function by a variety of mechanisms: The majority of mutations caused loss of mRNA due to nonsense-mediated mRNA decay; however, a recurrent, missense mutation (the G383D mutation) had both loss-of-function and dominant-negative activities. Regardless of mutation, all patient-derived neurons demonstrated reduced neurite growth and arborization, likely underlying diminished postnatal brain growth in patients. Phenotype rescue strategies showed mutation-specific responses: A gene transfer strategy was effective in nonsense mutations, but not in the G383D mutation, wherein residual protein appeared to interfere with rescue. In contrast, application of exogenous trophic factors (BDNF or IGF-1) rescued arborization phenotypes across all mutations. These results may guide treatment development in CS, including gene therapy strategies wherein our data suggest that response to treatment may be dictated by the class of mutation.

A white paper on a neurodevelopmental framework for drug discovery in autism and other neurodevelopmental disorders

In the last decade there has been a revolution in terms of genetic findings in neurodevelopmental disorders (NDDs), with many discoveries critical for understanding their aetiology and pathophysiology. Clinical trials in single-gene disorders such as fragile X syndrome highlight the challenges of investigating new drug targets in NDDs. Incorporating a developmental perspective into the process of drug development for NDDs could help to overcome some of the current difficulties in identifying and testing new treatments. This paper provides a summary of the proceedings of the 'New Frontiers Meeting' on neurodevelopmental disorders organised by the European College of Neuropsychopharmacology in conjunction with the Innovative Medicines Initiative-sponsored AIMS-2-TRIALS consortium. It brought together experts in developmental genetics, autism, NDDs, and clinical trials from academia and industry, regulators, patient and family associations, and other stakeholders. The meeting sought to provide a platform for focused communication on scientific insights, challenges, and methodologies that might be applicable to the development of CNS treatments from a neurodevelopmental perspective. Multidisciplinary translational consortia to develop basic and clinical research in parallel could be pivotal to advance knowledge in the field. Although implementation of clinical trials for NDDs in paediatric populations is widely acknowledged as essential, safety concerns should guide each aspect of their design. Industry and academia should join forces to improve knowledge of the biology of brain development, identify the optimal timing of interventions, and translate these findings into new drugs, allowing for the needs of users and families, with support from regulatory agencies.

Novel treatments for autism spectrum disorder based on genomics and systems biology

BACKGROUND

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder with a complex underlying genetic architecture. There are currently no known pharmacologic treatments for the core ASD symptoms of social deficits and restricted/ repetitive behavior. However, there are dozens of clinical trials currently underway that are testing the impact of novel and existing agents on core and associated symptoms in ASD.

METHODS

We present a narrative synthesis of the historical and contemporary challenges to drug discovery in ASD. We then provide an overview of novel treatments currently under investigation from a genomics and systems biology perspective.

RESULTS

Data driven network and cluster analyses suggest alterations in transcriptional regulation, chromatin remodelling, synaptic transmission, neuropeptide signalling, and/or immunological mechanisms may contribute to or underlie the development of ASD. Agents and upcoming trials targeting each of the above listed systems are reviewed.

CONCLUSION

Identifying effective pharmacologic treatments for the core and associated symptom domains in ASD will require further collaboration and innovation in the areas of outcome measurement, biomarker research, and genomics, as well as systematic efforts to identify and treat subgroups of individuals with ASD who may be differentially responsive to specific treatments.

Autism Spectrum Disorder: Signaling Pathways and Prospective Therapeutic Targets

The Autism Spectrum Disorder (ASD) consists of a prevalent and heterogeneous group of neurodevelopmental diseases representing a severe burden to affected individuals and their caretakers. Despite substantial improvement towards understanding of ASD etiology and pathogenesis, as well as increased social awareness and more intensive research, no effective drugs have been successfully developed to resolve the main and most cumbersome ASD symptoms. Hence, finding better treatments, which may act as "disease-modifying" agents, and novel biomarkers for earlier ASD diagnosis and disease stage determination are needed. Diverse mutations of core components and consequent malfunctions of several cell signaling pathways have already been found in ASD by a series of experimental platforms, including genetic associations analyses and studies utilizing pre-clinical animal models and patient samples. These signaling cascades govern a broad range of neurological features such as neuronal development, neurotransmission, metabolism, and homeostasis, as well as immune regulation and inflammation. Here, we review the current knowledge on signaling pathways which are commonly disrupted in ASD and autism-related conditions. As such, we further propose ways to translate these findings into the development of genetic and biochemical clinical tests for early autism detection. Moreover, we highlight some putative druggable targets along these pathways, which, upon further research efforts, may evolve into novel therapeutic interventions for certain ASD conditions. Lastly, we also refer to the crosstalk among these major signaling cascades as well as their putative implications in therapeutics. Based on this collective information, we believe that a timely and accurate modulation of these prominent pathways may shape the neurodevelopment and neuro-immune regulation of homeostatic patterns and, hopefully, rescue some (if not all) ASD phenotypes.

Effect of non-invasive brain stimulation on behavior and serum brain-derived neurotrophic factor and insulin-like growth factor-1 levels in autistic patients

Aberrant neural connectivity and intra-cortical inhibitory dysfunction are key features of autism. Non-invasive brain stimulation (NIBS) protocols have been proposed that modulate this aberrant plasticity. However, additional investigations are needed to evaluate the impact of this intervention on biological biomarkers of the disease. We recently demonstrated alterations in serum insulin-like growth factor-1 (IGF-1) and brain-derived neurotrophic factor (BDNF) immunoreactivity in subjects with autism compared to controls. The aim of this pilot study was to explore the change in serum levels of the neurotrophic factors BDNF and IGF-1 in patients undergoing NIBS therapy. Sixteen subjects with autism spectrum disorder (ASD) were tested 1 week before and 1 week after NIBS to determine the short-term outcome on behavior using the total score on the autism behavior checklist, autism treatment evaluation checklist, clinical global impression severity and the autism diagnostic interview. ASD subjects younger than 11 years old (n = 11) were treated with transcranial direct current stimulation (tDCS), and those 11 years and older (n = 5) were treated with repetitive transcranial magnetic stimulation (rTMS). Serum levels of BDNF and IGF-1 were evaluated by Enzyme-Linked Immuno-Sorbent Assay before and after the intervention with NIBS. A significant reduction in scores on the clinical behavioral scales was observed in patients treated with NIBS (ABC-T p = .002, CGI-S p = .008, ADI-T and ATEC-T p < .0001). There was a trend towards reduced serum BDNF levels after NIBS (p = .061), while there was no change in IGF-1 levels. These data support further studies on the potential of BDNF as a biomarker to measure the effectiveness of NIBS in autism.

Opportunities for ABA intervention in Phelan-McDermid syndrome

Phelan-McDermid syndrome (PMS), also called 22q13.3 deletion syndrome, is a rare genetic disorder affecting at least 2,000 people worldwide (Phelan-McDermid Syndrome Foundation, 2019, How rare is Phelan-McDermid?). PMS has many distinguishing characteristics and many medical specialties have been recommended to treat the clinical features. While many therapies, including behavioral therapy, have been speculated to be beneficial in treating PMS, there is little known regarding their effectiveness [Costales, J. L. and Kolevzon, A. 2015. Phelan-McDermid syndrome and SHANK3: Implications for treatment. Neurotherapeutics: The Journal of the American Society for Experimental Neurotherapeutics, 12, 620-630.]. Behavior analysis has the capability to help in many areas of treatment for PMS either directly through, for example, behavior treatment to address aggressive behavior, or through collaborating with other specialties treating PMS by combining, for example, behavioral principles in the alleviation of medical issues such as constipation. Currently, there is a role for the behavior analyst to expand our field and identify effective treatments for those with PMS while we wait for a cure. In this paper, we discuss how medical considerations may affect behavior interventions and make recommendations for the behavior analyst working with PMS.

A case report of Phelan-McDermid syndrome: preliminary results of the treatment with growth hormone therapy

BACKGROUND

Phelan-McDermid syndrome (PMS), also known as 22q13.3 deletion syndrome, is a rare neurodevelopmental syndrome resulting from a deletion of the distal long arm of chromosome 22.

CASE PRESENTATION

We report a case of a 21 months old Chinese girl presenting with global developmental delay, regression of language skills, unable to understand a few words or walk independently, insomnia, and autism-like behaviors. Copy number variation (CNV) analysis showed a heterozygous loss of SHANK3 gene in the 22q13 region, consistent with a diagnosis of PMS. After treatment with recombinant human growth hormone (rhGH), this patient had an improvement in motor skills and social behaviors. No side effects from rhGH therapy were reported.

CONCLUSIONS

This is the first report of using rhGH to treat a Chinese girl diagnosed with PMS. We speculate rhGH could be a reasonable alternative choice for PMS treatment with similar clinical outcomes in comparison to insulin-like growth factor-1(IGF-1). However, further clinical trials are needed to confirm this hypothesis.

Phelan McDermid Syndrome: Multiple Sclerosis as a Rare but Treatable Cause for Regression-A Case Report

Phelan McDermid syndrome (PMcD) is a neurogenetic disease associated with haploinsufficiency of the SHANK3 gene due to a spectrum of anomalies in the terminal region of the long arm of chromosome 22. SHANK3 is the abbreviation for SH3 domain and ankyrin repeat-containing protein, a gene that encodes for proteins of the postsynaptic density (PSD) of excitatory synapses. This PSD is relevant for the induction and plasticity of spine and synapse formation as a basis for learning processes and long-term potentiation. Individuals with PMcD present with intellectual disability, muscular hypotonia, and severely delayed or absent speech. Further neuropsychiatric manifestations cover symptoms of the autism spectrum, epilepsy, bipolar disorders, schizophrenia, and regression. Regression is one of the most feared syndromes by relatives of PMcD patients. Current scientific evidence indicates that the onset of regression is variable and affects language, motor skills, activities of daily living and cognition. In the case of regression, patients normally undergo further diagnostics to exclude treatable reasons such as complex-focal seizures or psychiatric comorbidities. Here, we report, for the first time, the case of a young female who developed progressive symptoms of regression and a dystonic-spastic hemiparesis that could be traced back to a comorbid multiple sclerosis and that improved after treatment with methylprednisolone.

Patient-Derived Induced Pluripotent Stem Cells (iPSCs) and Cerebral Organoids for Drug Screening and Development in Autism Spectrum Disorder: Opportunities and Challenges

Autism spectrum disorder (ASD) represents a group of neurodevelopmental diseases characterized by persistent deficits in social communication, interaction, and repetitive patterns of behaviors, interests, and activities. The etiopathogenesis is multifactorial with complex interactions between genetic and environmental factors. The clinical heterogeneity and complex etiology of this pediatric disorder have limited the development of pharmacological therapies. The major limit to ASD research remains a lack of relevant human disease models which can faithfully recapitulate key features of the human pathology and represent its genetic heterogeneity. Recent advances in induced pluripotent stem cells (iPSCs), reprogrammed from somatic cells of patients into all types of patient-specific neural cells, have provided a promising cellular tool for disease modeling and development of novel drug treatments. The iPSCs technology allowed not only a better investigation of the disease etiopathogenesis but also opened up the potential for personalized therapies and offered new opportunities for drug discovery, pharmacological screening, and toxicity assessment. Moreover, iPSCs can be differentiated and organized into three-dimensional (3D) organoids, providing a model which mimics the complexity of the brain’s architecture and more accurately recapitulates tissue- and organ-level disease pathophysiology. The aims of this review were to describe the current state of the art of the use of human patient-derived iPSCs and brain organoids in modeling ASD and developing novel therapeutic strategies and to discuss the opportunities and major challenges in this rapidly moving field.

Molecular mechanisms for targeted ASD treatments

The possibility to generate construct valid animal models enabled the development and testing of therapeutic strategies targeting the core features of autism spectrum disorders (ASDs). At the same time, these studies highlighted the necessity of identifying sensitive developmental time windows for successful therapeutic interventions. Animal and human studies also uncovered the possibility to stratify the variety of ASDs in molecularly distinct subgroups, potentially facilitating effective treatment design. Here, we focus on the molecular pathways emerging as commonly affected by mutations in diverse ASD-risk genes, on their role during critical windows of brain development and the potential treatments targeting these biological processes.

IGF-1 treatment causes unique transcriptional response in neurons from individuals with idiopathic autism

BACKGROUND

Research evidence accumulated in the past years in both rodent and human models for autism spectrum disorders (ASD) have established insulin-like growth factor 1 (IGF-1) as one of the most promising ASD therapeutic interventions to date. ASD is phenotypically and etiologically heterogeneous, making it challenging to uncover the underlying genetic and cellular pathophysiology of the condition; and to efficiently design drugs with widespread clinical benefits. While IGF-1 effects have been comprehensively studied in the literature, how IGF-1 activity may lead to therapeutic recovery in the ASD context is still largely unknown.

METHODS

In this study, we used a previously characterized neuronal population derived from induced pluripotent stem cells (iPSC) from neurotypical controls and idiopathic ASD individuals to study the transcriptional signature of acutely and chronically IGF-1-treated cells.

RESULTS

We present a comprehensive list of differentially regulated genes and molecular interactions resulting from IGF-1 exposure in developing neurons from controls and ASD individuals. Our results indicate that IGF-1 treatment has a different impact on neurons from ASD patients compared to controls. Response to IGF-1 treatment in neurons derived from ASD patients was heterogeneous and correlated with IGF-1 receptor expression, indicating that IGF-1 response may have responder and non-responder distinctions across cohorts of ASD patients. Our results suggest that caution should be used when predicting the effect of IGF-1 treatment on ASD patients using neurotypical controls. Instead, IGF-1 response should be studied in the context of ASD patients' neural cells.

LIMITATIONS

The limitation of our study is that our cohort of eight sporadic ASD individuals is comorbid with macrocephaly in childhood. Future studies will address weather downstream transcriptional response of IGF-1 is comparable in non-macrocephalic ASD cohorts.

CONCLUSIONS

The results presented in this study provide an important resource for researchers in the ASD field and underscore the necessity of using ASD patient lines to explore ASD neuronal-specific responses to drugs such as IGF-1. This study further helps to identify candidate pathways and targets for effective clinical intervention and may help to inform clinical trials in the future.

Bringing everyone to the table - findings from the 2018 Phelan-McDermid Syndrome Foundation International Conference

BACKGROUND

Phelan-McDermid Syndrome (PMS) is a rare neurodevelopmental disorder characterized by global developmental delay, autism spectrum disorder, and numerous systemic complications including seizures, gastrointestinal dysfunction, and renal anomalies. The Phelan-McDermid Syndrome Foundation (PMSF) was created to improve the quality of life of people affected by PMS worldwide by supporting families, accelerating research, and raising awareness. To further this mission, the PMSF initiated the Phelan-McPosium in 2016 to bring families affected by PMS, clinicians, and researchers together to design patient-centered rigorous clinical and translational research. Here, we present findings from the 2018 Phelan-McPosium.

RESULTS

The 2018 Phelan-McPosium was attended by 183 families and 35 researchers and clinicians. Overall, the Early Childhood parents raised the fewest number of concerns, families of Late-Childhood patients raised more concerns around epilepsy and behavioral problems, and Teen and Adult families were primarily concerned about implications of genetic testing, gastrointestinal dysfunction, and regression. All families were concerned with feasibility, safety and importance of clinical trials for PMS.

CONCLUSIONS

The concerns raised by families across the sessions varied by age in a manner which may overlap with the emergence of various signs and symptoms through the natural history of PMS. The design of the Phelan-McPosium session has successfully generated thoughtful research questions that led to innovative investigations and clinical trials that are shaping the standard of care for PMS. This is an approach which could be employed by any rare disease group to align translational research efforts with a patient-centered focus.

Neuroinflammatory Gene Expression Alterations in Anterior Cingulate Cortical White and Gray Matter of Males With Autism Spectrum Disorder

Evidence for putative pathophysiological mechanisms of autism spectrum disorder (ASD), including peripheral inflammation, blood-brain barrier disruption, white matter alterations, and abnormal synaptic overgrowth, indicate a possible involvement of neuroinflammation in the disorder. Neuroinflammation plays a role in the development and maintenance of the dendritic spines involved in glutamatergic and GABAergic neurotransmission, and also influences blood-brain permeability. Cytokines released from microglia can impact the length, location or organization of dendritic spines on excitatory and inhibitory cells as well as recruit and impact glial cell function around the neurons. In this study, gene expression levels of anti- and pro-inflammatory signaling molecules, as well as oligodendrocyte and astrocyte marker proteins, were measured in both gray and white matter tissue in the anterior cingulate cortex from ASD and age-matched typically developing (TD) control brain donors, ranging from ages 4 to 37 years. Expression levels of the pro-inflammatory gene, HLA-DR, were significantly reduced in gray matter and expression levels of the anti-inflammatory gene MRC1 were significantly elevated in white matter from ASD donors as compared to TD donors, but neither retained statistical significance after correction for multiple comparisons. Modest trends toward differences in expression levels were also observed for the pro-inflammatory (CD68, IL1β) and anti-inflammatory genes (IGF1, IGF1R) comparing ASD donors to TD donors. The direction of gene expression changes comparing ASD to TD donors did not reveal consistent findings implicating an elevated pro- or anti-inflammatory state in ASD. However, altered expression of pro- and anti-inflammatory gene expression indicates some involvement of neuroinflammation in ASD. Autism Res 2020, 13: 870-884. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: The anterior cingulate cortex is an integral brain region in modulating social behaviors including nonverbal communication. The study found that inflammatory gene expression levels were altered in this brain region. We hypothesize that the inflammatory changes in this area could impact neuronal function. The finding has future implications in using these molecular markers to identify potential environmental exposures and distinct cell differences in autism.

Peripheral Blood Mononuclear Cell Oxytocin and Vasopressin Receptor Expression Positively Correlates with Social and Behavioral Function in Children with Autism

The peptide hormone oxytocin is an established regulator of social function in mammals, and dysregulated oxytocin signaling is implicated in autism spectrum disorder (ASD). Several clinical trials examining the effects of intranasal oxytocin for improving social and behavioral function in ASD have had mixed or inclusive outcomes. The heterogeneity in clinical trials outcomes may reflect large inter-individual expression variations of the oxytocin and/or vasopressin receptor genes OXTR and AVPR1A, respectively. To explore this hypothesis we examined the expression of both genes in peripheral blood mononuclear cells (PBMC) from ASD children, their non-ASD siblings, and age-matched neurotypical children aged 3 to 16 years of age as well as datamined published ASD datasets. Both genes were found to have large inter-individual variations. Higher OXTR and AVPR1A expression was associated with lower Aberrant Behavior Checklist (ABC) scores. OXTR expression was associated with less severe behavior and higher adaptive behavior on additional standardized measures. Combining the sum expression levels OXTR, AVPR1A, and IGF1 yielded the strongest correlation with ABC scores. We propose that future clinical trials in ASD children with oxytocin, oxytocin mimetics and additional tentative therapeutics should assess the prognostic value of their PBMC mRNA expression of OXTR, AVPR1A, and IGF1.