Treatment studies in knockout rodent models have found that minocycline and lovastatin each improve synaptic, neurological, and behavioral functioning, and open-label chronic dosing studies in human patients with fragile X syndrome (FXS) have demonstrated modest clinical improvements. Findings from blinded studies are mixed, and there is a limited understanding of electrophysiological target engagement that would facilitate cross-species translational studies. Smaller-scale, acute (e.
View Article and Find Full Text PDFEstimating meaningful change thresholds (MCT) on clinical outcome assessments is an important consideration when evaluating treatments. In fragile X syndrome (FXS) research, there has been no consensus on how to define MCT's on several commonly used outcome measures. The purpose of the current study was to determine clinically relevant MCT's of caregiver-rated assessments using data from a phase 3 clinical trials of arbaclofen (Berry-Kravis et al.
View Article and Find Full Text PDFIntroduction: Autistic children and adolescents frequently experience emotion dysregulation, or difficulties with appropriately modifying their emotional reactions. Caregivers of autistic teens frequently seek psychotherapy support for navigating challenges associated with emotion dysregulation. During the COVID-19 pandemic, access to clinical services became limited, with interventions halted or transitioned into a telehealth format.
View Article and Find Full Text PDFFragile X Syndrome (FXS) is an X-linked disorder leading to the loss of expression of FMR1-protein product, FMRP. The absence or deficiency of FMRP is thought to result in the characteristic FXS phenotypes, including intellectual disability. Identifying the relationship between FMRP levels and IQ may be critical to better understand underlying mechanisms and advance treatment development and planning.
View Article and Find Full Text PDFAutistic youth experience several behavioral and emotional characteristics that can predispose them to emotion dysregulation (ED). Current literature examining ED in autism spectrum disorder (ASD) is limited to parent- and self-reported measures, indicating a need for biological or physiological methods to better assess emotion regulation in ASD. Utilizing the autonomic nervous system, specifically heart rate variability (HRV), may be a promising method to objectively measure ED in ASD, given it is one of the body's primary means of regulating physiological arousal.
View Article and Find Full Text PDFFragile X syndrome (FXS) is an X-linked disorder that often leads to intellectual disability, anxiety, and sensory hypersensitivity. While sound sensitivity (hyperacusis) is a distressing symptom in FXS, its neural basis is not well understood. It is postulated that hyperacusis may stem from temporal lobe hyperexcitability or dysregulation in top-down modulation.
View Article and Find Full Text PDFBiomark Neuropsychiatry
December 2023
Objective: Fragile X Syndrome (FXS) is the leading monogenic cause of intellectual disability and autism spectrum disorder. Currently, there are no established biomarkers for predicting and monitoring drug effects in FXS, and no approved therapies are available. Previous studies have shown electrophysiological changes in the brain using electroencephalography (EEG) in individuals with FXS and animal models.
View Article and Find Full Text PDFNeuroinflammatory mechanisms have been implicated in the pathophysiology of autism spectrum disorder (ASD). Minocycline is a matrix metalloproteinase inhibitor 9 (MMP9) inhibitor tetracycline antibiotic with known anti-inflammatory properties. In preclinical animal models of ASD, minocycline has demonstrated potential positive effects on phenotypes that may have relevance to ASD.
View Article and Find Full Text PDFPurpose: The construct Quality of Life (QoL) involves a range of factors related to one's well-being. Individuals on the autism spectrum have been previously reported to have lower QoL. The purpose of the present study is to examine QoL in autistic individuals and their families and to evaluate associations between QoL and measures of functioning using the PedsQL 4.
View Article and Find Full Text PDFThe FMR1 gene is inactive in Fragile X syndrome (FXS), resulting in low levels of FMRP and consequent neurochemical, synaptic, and local circuit neurophysiological alterations in the fmr1 KO mouse. In FXS patients, electrophysiological studies have demonstrated a marked reduction in global alpha activity and regional increases in gamma oscillations associated with intellectual disability and sensory hypersensitivity. Since alpha activity is associated with a thalamocortical function with widely distributed modulatory effects on neocortical excitability, insight into alpha physiology may provide insight into systems-level disease mechanisms.
View Article and Find Full Text PDFBackground: There is a critical need for the development of improved outcome measures in Fragile X Syndrome (FXS). Because the majority of respondents of behavior outcome measures are caregivers or individuals with FXS, it is important to consider stakeholders' firsthand experiences when designing a caregiver- or self-report measure.
Aims: The current research study aimed to understand experiences of completing commonly used caregiver-/self-report measures of behavior in FXS via focus groups.
Introduction: Behavioral difficulties in individuals with fragile X Syndrome (FXS) are one of the primary reasons families seek medical and psychological support. Among these, behavioral inflexibility is very common, and when left untreated, can negatively impact quality of life for the individuals with FXS and their families. Behavioral inflexibility refers to the difficulty in changing one's behaviors based on environmental demands or social contexts, thus impeding daily functioning, opportunities for learning, and social interactions.
View Article and Find Full Text PDFJ Am Acad Child Adolesc Psychiatry
May 2023
Objective: Extracellular signal-regulated kinase (ERK1/2) is a conserved central intracellular signaling cascade involved in many aspects of neuronal development and plasticity. Converging evidence support investigation of ERK1/2 activity in autism spectrum disorder (ASD). We previously reported enhanced baseline lymphocytic ERK1/2 activation in autism, and now we extend our work to investigate the early phase kinetics of lymphocytic ERK1/2 activation in idiopathic ASD.
View Article and Find Full Text PDFJ Am Acad Child Adolesc Psychiatry
May 2023
Objective: To summarize the current state of the literature regarding emotion dysregulation (ED) in syndromic intellectual disabilities (S-IDs) in 6 of the most common forms of S-IDs-Down syndrome, fragile X syndrome (FXS), tuberous sclerosis complex, Williams syndrome, Prader-Willi syndrome, and Angelman syndrome-and to determine future research directions for identification and treatment of ED.
Method: PubMed bibliographic database was searched from date of inception to May 2021. PRISMA 2020 guidelines were followed with the flowchart, table of included studies, list of excluded studies, and checklist provided.
Children's ability to share attention with another person (i.e., achieve joint attention) is critical for learning about their environments in general and supporting language and object word learning in particular.
View Article and Find Full Text PDFFragile X Syndrome (FXS) is a monogenetic form of intellectual disability and autism in which well-established knockout (KO) animal models point to neuronal hyperexcitability and abnormal gamma-frequency physiology as a basis for key disorder features. Translating these findings into patients may identify tractable treatment targets. Using source modeling of resting-state electroencephalography data, we report findings in FXS, including 1) increases in localized gamma activity, 2) pervasive changes of theta/alpha activity, indicative of disrupted thalamocortical modulation coupled with elevated gamma power, 3) stepwise moderation of low and high-frequency abnormalities based on female sex, and 4) relationship of this physiology to intellectual disability and neuropsychiatric symptoms.
View Article and Find Full Text PDFIndividuals with autism spectrum disorder (ASD) experience behavioral and emotional symptoms hypothesized to arise from emotion dysregulation (ED), difficulty modulating emotional experience, expression, and intensity in an acceptable and contextually appropriate manner. We developed Regulating Together (RT)-an intensive-outpatient, caregiver-assisted group program to meet the ASD + ED intervention critical need. A within-subjects trial was conducted (5-week-control lead-in period, 5-week-treatment, and 5-and 10-weeks-post-treatment follow-ups).
View Article and Find Full Text PDFGastrointestinal (GI) disorders are common in children with neurodevelopmental disorders such as autism spectrum disorder (ASD). A limited understanding of the biologic factors that predispose this population to GI disorders has prevented development of individualized therapies to address this important medical issue. The goal of the current study was to determine if elements of the salivary micro-transcriptome could provide insight into the biologic perturbations unique to children with ASD-related GI disturbance.
View Article and Find Full Text PDFThe current study evaluates the concurrent relationship between parent ratings of executive functioning and maladaptive behavior among children and adolescents with Down syndrome and then repeats this evaluation using teacher reports. Parents and teachers of 63 school-age children with Down syndrome rated the child's executive functioning (Behavior Rating Inventory of Executive Function) and behaviors (Achenbach Child Behavior Checklist). For parent and teacher ratings, elevated behavior dysregulation predicted higher levels of rule-breaking, aggressive, and externalizing behavior.
View Article and Find Full Text PDFElectrophysiological alterations may represent a neural substrate of impaired neurocognitive processes and other phenotypic features in Fragile X Syndrome (FXS). However, the role of biological sex in electroencephalography (EEG) patterns that differentiate FXS from typical development has not been determined. This limits use of EEG in both the search for biomarkers of impairment in FXS as well as application of those markers to enhance our understanding of underlying neural mechanisms to speed treatment discovery.
View Article and Find Full Text PDFMultimodal exploration of objects during toy play is important for a child's development and is suggested to be abnormal in children with autism spectrum disorder (ASD) due to either atypical attention or atypical action. However, little is known about how children with ASD coordinate their visual attention and manual actions during toy play. The current study aims to understand if and in what ways children with ASD generate exploratory behaviors to toys in natural, unconstrained contexts by utilizing head-mounted eye tracking to quantify moment-by-moment attention.
View Article and Find Full Text PDFDysregulation of glutamate neurotransmission plays a critical role in autism spectrum disorder (ASD) pathophysiology and is a primary target for core deficit research treatment trials. The mechanism of action of ketamine has striking overlap with the theory of ASD as a disorder of synaptic communication and neuronal networks. This two-dose, double-blind, placebo controlled, cross-over pilot trial of intranasal (IN) ketamine targeting core social impairment included individuals with ASD (N = 21) between 14 and 29 years.
View Article and Find Full Text PDFRestricted repetitive behaviors (RRBs) are a core area of impairment in autism spectrum disorder (ASD), but also affect several other neurodevelopmental disorders including fragile X syndrome (FXS). Current literature has begun to describe the RRB profile in FXS up through adolescence; however, little is known about the subtypes of RRBs in adolescents and adults. Further, literature on the RRB profile of females with FXS is limited.
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