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BioRxiv : the Preprint Server For... Mar 2024Epigenome editing with DNA-targeting technologies such as CRISPR-dCas9 can be used to dissect gene regulatory mechanisms and potentially treat associated disorders. For...
Epigenome editing with DNA-targeting technologies such as CRISPR-dCas9 can be used to dissect gene regulatory mechanisms and potentially treat associated disorders. For example, Prader-Willi Syndrome (PWS) is caused by loss of paternally expressed imprinted genes on chromosome 15q11.2-q13.3, although the maternal allele is intact but epigenetically silenced. Using CRISPR repression and activation screens in human induced pluripotent stem cells (iPSCs), we identified genomic elements that control expression of the PWS gene from the paternal and maternal chromosomes. We showed that either targeted transcriptional activation or DNA demethylation can activate the silenced maternal and downstream PWS transcripts. However, these two approaches function at unique regions, preferentially activating different transcript variants and involving distinct epigenetic reprogramming mechanisms. Remarkably, transient expression of the targeted demethylase leads to stable, long-term maternal expression in PWS iPSCs. This work uncovers targeted epigenetic manipulations to reprogram a disease-associated imprinted locus and suggests possible therapeutic interventions.
PubMed: 38496583
DOI: 10.1101/2024.03.03.583177 -
Frontiers in Neuroscience 2024
PubMed: 38476870
DOI: 10.3389/fnins.2024.1370030 -
Frontiers in Cellular Neuroscience 2024This perspective review aims to explore the potential neurobiological mechanisms involved in the application of transcranial Direct Current Stimulation (tDCS) for Down...
This perspective review aims to explore the potential neurobiological mechanisms involved in the application of transcranial Direct Current Stimulation (tDCS) for Down syndrome (DS), the leading cause of genetically-based intellectual disability. The neural mechanisms underlying tDCS interventions in genetic disorders, typically characterized by cognitive deficits, are grounded in the concept of brain plasticity. We initially present the neurobiological and functional effects elicited by tDCS applications in enhancing neuroplasticity and in regulating the excitatory/inhibitory balance, both associated with cognitive improvement in the general population. The review begins with evidence on tDCS applications in five neurogenetic disorders, including Rett, Prader-Willi, Phelan-McDermid, and Neurofibromatosis 1 syndromes, as well as DS. Available evidence supports tDCS as a potential intervention tool and underscores the importance of advancing neurobiological research into the mechanisms of tDCS action in these conditions. We then discuss the potential of tDCS as a promising non-invasive strategy to mitigate deficits in plasticity and promote fine-tuning of the excitatory/inhibitory balance in DS, exploring implications for cognitive treatment perspectives in this population.
PubMed: 38456063
DOI: 10.3389/fncel.2024.1328963 -
European Journal of Endocrinology Mar 2024A major issue in the management of craniopharyngioma-related obesity (CRO) is the ineffectiveness of the current therapeutic approaches. (Randomized Controlled Trial)
Randomized Controlled Trial
IMPORTANCE
A major issue in the management of craniopharyngioma-related obesity (CRO) is the ineffectiveness of the current therapeutic approaches.
OBJECTIVE
To study the efficacy of glucagon-like peptide-1 analogs compared with placebo in adults with obesity CRO.
DESIGN
A double-blind multicenter superiority randomized clinical in trial in two parallel arms.
SETTING
Eleven French University Hospital Centers.
PARTICIPANTS
Adults with CRO (body mass index > 30 kg/m²) without the sign of recurrence of craniopharyngioma in the past year.
INTERVENTIONS
Exenatide or placebo injected subcutaneously twice a day during 26 weeks.
MAIN OUTCOMES AND MEASURES
The primary outcome was the mean change in body weight at week 26 in the intention-to-treat population. Secondary outcomes were eating behavior, calories intake, energy expenditure, cardiovascular, metabolic risk factor, quality of life, and the tolerance profile.
RESULTS
At week 26, weight decreased from baseline by a mean of -3.8 (SD 4.3) kg for exenatide and -1.6 (3.8) kg for placebo. The adjusted mean treatment difference was -3.1 kg (95% confidence interval [CI] -7.0 to 0.7, P = 0.11). Results were compatible with a higher reduction of hunger score with exenatide compared with placebo (estimated treatment difference in change from baseline to week 26: -2.3, 95% CI -4.5 to -0.2), while all other outcomes did not significantly differ between groups. Adverse events were more common with exenatide versus placebo, and occurred in, respectively, 19 (95%) participants (108 events) and 14 (70%) participants (54 events).
CONCLUSIONS AND RELEVANCE
Combined with intensive lifestyle interventions, a 26-week treatment with exenatide was not demonstrated superior to placebo to treat craniopharyngioma-related obesity.
Topics: Adult; Humans; Exenatide; Hypoglycemic Agents; Quality of Life; Craniopharyngioma; Obesity; Weight Loss; Feeding Behavior; Pituitary Neoplasms; Double-Blind Method
PubMed: 38450721
DOI: 10.1093/ejendo/lvae024 -
Clinical Dysmorphology Apr 2024
Review
Topics: Humans; Syndrome; Facies; Chromosome Disorders; Developmental Disabilities; Hypopituitarism; Imprinting Disorders
PubMed: 38441201
DOI: 10.1097/MCD.0000000000000491 -
Neurotherapeutics : the Journal of the... Apr 2024Prader-Willi syndrome (PWS) is a complex, genetic disorder characterized by multisystem involvement, including hyperphagia, maladaptive behaviors and endocrinological... (Review)
Review
Prader-Willi syndrome (PWS) is a complex, genetic disorder characterized by multisystem involvement, including hyperphagia, maladaptive behaviors and endocrinological derangements. Recent developments in advanced neuroimaging have led to a growing understanding of PWS as a neural circuit disorder, as well as subsequent interests in the application of neuromodulatory therapies. Various non-invasive and invasive device-based neuromodulation methods, including vagus nerve stimulation (VNS), transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), and deep brain stimulation (DBS) have all been reported to be potentially promising treatments for addressing the major symptoms of PWS. In this systematic literature review, we summarize the recent literature that investigated these therapies, discuss the underlying circuits which may underpin symptom manifestations, and cover future directions of the field. Through our comprehensive search, there were a total of 47 patients who had undergone device-based neuromodulation therapy for PWS. Two articles described VNS, 4 tDCS, 1 rTMS and 2 DBS, targeting different symptoms of PWS, including aberrant behavior, hyperphagia and weight. Multi-center and multi-country efforts will be required to advance the field given the low prevalence of PWS. Finally, given the potentially vulnerable population, neuroethical considerations and dialogue should guide the field.
Topics: Humans; Prader-Willi Syndrome; Vagus Nerve Stimulation; Transcranial Magnetic Stimulation; Deep Brain Stimulation; Transcranial Direct Current Stimulation
PubMed: 38430811
DOI: 10.1016/j.neurot.2024.e00339 -
Journal of Clinical Sleep Medicine :... Mar 2024Our aim was to characterize the 14 and 6 like spike wave activity seen on electroencephalogram (EEG) in children with Prader-Willi syndrome (PWS) undergoing...
STUDY OBJECTIVES
Our aim was to characterize the 14 and 6 like spike wave activity seen on electroencephalogram (EEG) in children with Prader-Willi syndrome (PWS) undergoing polysomnogram (PSG).
METHODS
We performed a retrospective review of children with PWS and healthy controls who underwent diagnostic PSGs between January 1, 2007 to December 31, 2020 at SickKids, Toronto, Canada. EEGs from the PSGs were reviewed for the presence of the 14 and 6 like spike wave activity and its characteristics. Clinical correlation of the EEG variant with sleep disordered breathing indices from the PSG was also evaluated.
RESULTS
94 children with PWS and 50 healthy controls were included. The age, median (IQR) for the cohort was 1.42 (0.6, 4.2) years. There were 50 (53.2%) males in the PWS cohort. The EEG variant prevalence in this cohort was 51.0% (n=48) in children with PWS and 0% for the healthy controls. 14 and 6 Hz like spike wave activity was bilateral in 52% (25/48) children with PWS. The waves had a negative deflection in almost all patients 44/48 (92%) with PWS. It was predominantly located in the frontal leads for children with PWS, 23/48 (47.9%). It most frequently occurred during NREM stage 2 sleep for children with PWS, 25/48 (52.0%). The mean (SD) frequency was 6.8 (0.97) Hz. The median (IQR) length of the waves was 1.1 (0.8, 1.4) seconds in children with PWS. There was no correlation between the presence of the EEG variant and sleep disordered breathing indices in children with PWS.
CONCLUSIONS
14 and 6 Hz like spike wave activity EEG variant was present in more than 50% of a pediatric cohort of PWS as compared to 0% in healthy children. This EEG variant did not appear to be associated with sleep disordered breathing indices in children with PWS and is of unknown clinical significance.
PubMed: 38427317
DOI: 10.5664/jcsm.11078 -
American Journal on Intellectual and... Mar 2024Neurogenetic conditions (NGC; e.g., fragile X, Angelman, Prader-Willi syndromes) represent the cause for intellectual or developmental disabilities in up to 60% of...
Neurogenetic conditions (NGC; e.g., fragile X, Angelman, Prader-Willi syndromes) represent the cause for intellectual or developmental disabilities in up to 60% of cases. With expanded diagnostic options and an increasing focus on the development of gene therapies comes the potential of improved quality of life for individuals with NGCs and their families. However, these emerging initiatives also bring new challenges and considerations for NGC researchers and clinicians, including considerations for supporting caregivers and assuring outcome measures for clinical trials adequately reflect the lived experiences of people with NGCs. This paper summarizes the advances and current and future challenges of research and clinical service provision for people with NGCs and their caregivers.
Topics: Humans; Quality of Life; Prader-Willi Syndrome
PubMed: 38411239
DOI: 10.1352/1944-7558-129.2.110 -
Children (Basel, Switzerland) Jan 2024Obesity is a significant health problem with a continuously increasing prevalence among children and adolescents that has become a modern pandemic during the last... (Review)
Review
Obesity is a significant health problem with a continuously increasing prevalence among children and adolescents that has become a modern pandemic during the last decades. Nowadays, the genetic contribution to obesity is well-established. For this narrative review article, we searched PubMed and Scopus databases for peer-reviewed research, review articles, and meta-analyses regarding the genetics of obesity and current pharmacological treatment, published in the English language with no time restrictions. We also screened the references of the selected articles for possible additional articles in order to include most of the key recent evidence. Our research was conducted between December 2022 and December 2023. We used the terms "obesity", "genetics", "monogenic", "syndromic", "drugs", "autosomal dominant", "autosomal recessive", "leptin-melanocortin pathway", and "children" in different combinations. Recognizing the genetic background in obesity can enhance the effectiveness of treatment. During the last years, intense research in the field of obesity treatment has increased the number of available drugs. This review analyzes the main categories of syndromic and monogenic obesity discussing current data on genetic-based pharmacological treatment of genetic obesity and highlighting the necessity that cases of genetic obesity should follow specific, pharmacological treatment based on their genetic background.
PubMed: 38397265
DOI: 10.3390/children11020153