Sensory Symptoms and Signs of Hyperarousal in Individuals with Fragile X Syndrome: Findings from the FORWARD Registry and Database Multisite Study

Differential effects of sound repetition rate on auditory cortex development and behavior in fragile X syndrome mouse model

Fragile X syndrome (FXS) is a leading genetic form of autism and intellectual disability that is associated with a loss-of-function mutation in the Fragile X messenger ribonucleoprotein 1 (Fmr1) gene. The Fmr1 knockout (KO) mouse model displays many aspects of FXS-related phenotypes and is used to study FXS pathophysiology. Sensory manipulations, such as sound exposure, are considered as a non-invasive approach to alleviate FXS phenotypes. However, it is unclear what specific sound attributes may have beneficial effects. In this study, we examined the effects of sound repetition rate on auditory cortex development and FXS-associated behaviors in a mouse model of FXS. KO and wild-type (WT) male littermates were exposed to 14 kHz pure tone trains with 1 Hz or 5 Hz repetition rates during postnatal day (P)9-P21 developmental period. We analyzed the effects of developmental sound exposure on PV cell development, cortical activity and exploratory behaviors in sound-exposed WT and KO mice. We found that parvalbumin (PV) cell density was lower in the auditory cortex (AuC) of KO compared to WT mice raised in sound-attenuated environment, but was increased following the exposure to both 1 Hz and 5 Hz sound trains. However, PV protein levels were upregulated only in AuC of 5 Hz rate exposed KO mice. Interestingly, analysis of baseline cortical activity using electroencephalography (EEG) recordings showed that sound attenuation or exposure to sound trains with 5 Hz, but not 1 Hz, repetition rates corrected enhanced resting state gamma power in AuC of KO mice to WT levels. In addition, sound attenuation and exposure to 5 Hz showed some beneficial effects on the synchronization to frequency-modulated chirp in the frontal cortex (FC) of both WT and KO mice. Analysis of event-related potentials (ERP) in response to broadband sound showed increased ongoing responses and decreased habituation to noise stimuli in the AuC and FC of naive KO mice. While sound-attenuation and exposure to 5 Hz showed no significant effects on the power of onset and ongoing responses, exposure to 1 Hz further enhanced ongoing responses and decreased habituation to sound in both WT and KO mice. Finally, developmental exposure to sound trains with 5 Hz, but not 1 Hz, repetition rates normalized exploratory behaviors and improved social novelty preference but not hyperactivity in KO mice. Summarizing, our results show that developmental exposure of mice to sound trains with 5 Hz, but not 1 Hz, repetition rate had beneficial effects on PV cell development, overall cortical activity and behaviors in KO mice. While sound attenuation alone normalized some EEG phenotypes, it did not improve PV development or behaviors. These findings may have a significant impact on developing new approaches to alleviate FXS phenotypes and open possibilities for a combination of sound exposure with drug treatment which may offer highly novel therapeutic approaches.

The Aberrant Behavior Checklist for Fragile X Syndrome: A Qualitative Clinician Evaluation of Content Validity

Objective: The current intense period of drug development for fragile X syndrome (FXS) and other neurodevelopmental disorders (NDDs) indications has highlighted the importance of behavioral outcome measures with strong psychometric properties and specifically content validity. The Aberrant Behavior Checklist-Community Edition (ABC-C), which has successfully been applied to autism spectrum disorder drug trials, has been revised for FXS (ABCFX) and is widely used for both clinical and research purposes. Despite its strong psychometric validation, the ABCFX and its parent measure have not been subjected to qualitative content validity evaluations. The present study intended to fill this gap. Methods: Using two surveys administered sequentially and developed with guidance and review from the Food and Drug Administration (FDA), we asked 10 clinicians experienced in FXS and related NDDs to determine the adequacy of the ABCFX for assessing its behavioral constructs, its relevance to FXS, and its potential for detecting response to interventions. Various descriptive statistic parameters and ad hoc metrics were used to analyze categorical and Likert-like scale responses. Results: Experts considered that most items and all six ABCFX subscales indeed evaluated their explicit or implicit behavioral constructs. However, item and subscale specificity were relatively low (∼25%-30%). Relevance of items of the Hyperactivity subscale was relatively high while low for many items of the Socially Unresponsive/Lethargic subscale. These items were also considered of low responsiveness potential. Irritability, Hyperactivity, Stereotypy, and Social Avoidance were the subscales with the strongest profiles, although the experts estimated that Stereotypy items may not be that responsive to treatment. A novel Anxiety construct, representing mainly recently reported observable behaviors, contributed mainly by Irritability items, emerged as a potential measure. Conclusions: The present study demonstrated the overall adequacy of the ABCFX for its behavioral constructs, its relevance to FXS, and its potential for detecting response to treatment. It also showed that anxiety, a distinctive feature of FXS and other genetic NDDs, can also be measured by the ABCFX. These findings can help with the implementation and interpretation of the ABCFX, as well as with potential improvements to the measure in FXS and other NDDs.

Operationalising routinely collected patient data in research to further the pursuit of social justice and health equity: a team-based scoping review

BACKGROUND

Vast volumes of routinely collected data (RCD) about patients are collated by health professionals. Leveraging this data - a form of real-world data - can be valuable for quality improvement and contributing to the evidence-base to inform practice. Examining routine data may be especially useful for examining issues related to social justice such as health inequities. However, little is known about the extent to which RCD is utilised in health fields and published for wider dissemination.

OBJECTIVES

The objective of this scoping review is to document the peer-reviewed published research in allied health fields which utilise RCD and evaluate the extent to which these studies have addressed issues pertaining to social justice.

METHODS

An enhanced version of the Arksey and O'Malley's framework, put forth by Westphalm et al. guided the scoping review. A comprehensive literature search of three databases identified 1584 articles. Application of inclusion and exclusion criteria was piloted on 5% of the papers by three researchers. All titles and abstracts were screened independently by 2 team members, as were full texts. A data charting framework, developed to address the research questions, was piloted by three researchers with data extraction being completed by the lead researcher. A sample of papers were independently charted by a second researcher for reliability checking.

RESULTS

One hundred and ninety papers were included in the review. The literature was diverse in terms of the professions that were represented: physiotherapy (33.7%) and psychology/mental health professions (15.8%) predominated. Many studies were first authored by clinicians (44.2%), often with clinical-academic teams. Some (33.25%) directly referenced the use of their studies to examine translation of research to practice. Few studies (14.2%) specifically tackled issues pertaining to social justice, though many collected variables that could have been utilised for this purpose.

CONCLUSION

Studies operationalising RCD can meaningfully address research to practice gaps and provide new evidence about issues related to social justice. However, RCD is underutilised for these purposes. Given that vast volumes of relevant data are routinely collected, more needs to be done to leverage it, which would be supported by greater acknowledgement of the value of RCD studies.

Suppression of astrocyte BMP signaling improves fragile X syndrome molecular signatures and functional deficits

Fragile X syndrome (FXS) is a monogenic neurodevelopmental disorder with manifestations spanning molecular, neuroanatomical, and behavioral changes. Astrocytes contribute to FXS pathogenesis and show hundreds of dysregulated genes and proteins; targeting upstream pathways mediating astrocyte changes in FXS could therefore be a point of intervention. To address this, we focused on the bone morphogenetic protein (BMP) pathway, which is upregulated in FXS astrocytes. We generated a conditional KO (cKO) of Smad4 in astrocytes to suppress BMP signaling, and found this lessens audiogenic seizure severity in FXS mice. To ask how this occurs on a molecular level, we performed in vivo transcriptomic and proteomic profiling of cortical astrocytes, finding upregulation of metabolic pathways, and downregulation of secretory machinery and secreted proteins in FXS astrocytes, with these alterations no longer present when BMP signaling is suppressed. Functionally, astrocyte Smad4 cKO restores deficits in inhibitory synapses present in FXS auditory cortex. Thus, astrocytes contribute to FXS molecular and functional phenotypes, and targeting astrocytes can mitigate FXS symptoms.

A holistic approach to fragile X syndrome integrated guidance for person-centred care

BACKGROUND

The Fragile X community has expressed a desire for centralised, national guidelines in the form of integrated guidance for Fragile X Syndrome (FXS).

METHODS

This article draws on existing literature reviews, primary research and clinical trials on FXS, a Fragile X Society conference workshop and first-hand experience of clinicians who have worked with those living with FXS over many years.

RESULTS

The article scopes proposed integrated guidance over the life course, including appendices of symptoms, comorbidities and referral options for FXS and Fragile X Premutation Associated Conditions.

CONCLUSION

Integrated guidance would provide an authoritative source for doctors, health professionals, therapists, care workers, social workers, educators, employers, families and those living with FXS, so that a holistic, person-centred approach can be taken across the United Kingdom to garner the best outcomes for those with FXS.