Treatments for fragile X syndrome: a closer look at the data

Examining Phenotypic Differences in Gaze Avoidance Between Autism Spectrum Disorder and Fragile X Syndrome

We examined potential phenotypic differences in eye gaze avoidance exhibited by boys with autism spectrum disorder (ASD) and boys with fragile X syndrome (FXS). In Study 1, the Eye Contact Avoidance Scale (ECAS) was administered to caregivers of boys aged 7-18 years with FXS (n = 148), ASD (n = 168), and mixed developmental disabilities (MDD; n = 128). In Study 2, subsets of boys with FXS (n = 31) and boys with ASD (n = 25) received a brief behavioral treatment probe to improve eye contact. Results showed that boys with FXS obtained significantly higher scores on the ECAS compared to boys with ASD and MDD. Exposure to the brief behavioral treatment probe resulted in significant decreases in scores for boys with FXS, but not for boys with ASD.

Telehealth-enabled behavioral treatment for problem behaviors in boys with fragile X syndrome: a randomized controlled trial

Background

Children with fragile X syndrome (FXS) are at increased risk for exhibiting problem behaviors such as aggression and self-injury. However, many children with FXS have limited access to behavioral treatments that have known efficacy due to the low availability of treatment providers and the wide geographical dispersion of families with FXS across the country. Telehealth may offer a cost-effective and practical solution to overcome these significant barriers. We examined the effect of administering an established behavior analytic intervention called functional communication training (FCT) via telehealth on levels of problem behaviors exhibited by boys with FXS. We also examined treatment acceptability, as well as the effect of the treatment on levels of parenting stress.

Methods

Boys with FXS, aged 3 to 10 years, who displayed problem behaviors daily, were randomized to receive FCT via telehealth (n = 30) or treatment as usual (n = 27) over 12 weeks. Outcome measures included in-session observations of problem behavior, the Aberrant Behavior Checklist—Community (ABC-C), the Treatment Acceptability Rating Form—Revised (TARF-R), and the Parenting Stress Index, 4th edition (PSI-4).

Results

Intention-to-treat analyses indicated that scores on the irritability subscale of the ABC-C, our primary outcome measure, decreased significantly for boys who received FCT via telehealth compared to boys who received treatment as usual (p < .001, Cohen’s d = 0.65). In-session observations conducted for those who received treatment showed that levels of problem behavior decreased by 91% from baseline. Levels of parenting stress related to child behavioral problems were also lower following FCT treatment, and caregivers reported that the intervention was acceptable.

Conclusions

These findings support telehealth-enabled FCT as a framework for expanding access to behavioral treatments for problem behaviors in children with FXS. Expanded delivery of behavior analytic treatment via telehealth also has the potential to lower healthcare costs, improve child and family quality of life, and lead to advances in the treatment of problem behavior in the broader population of individuals with neurodevelopmental disorders.

Trial registration

ClinicalTrials.gov, NCT03510156. Registered 27 April 2018

Examining the Specificity of Forms and Functions of Aggressive Behavior in Boys With Fragile X Syndrome

Limited information is available concerning the specificity of the forms and functions of aggressive behavior exhibited by boys with fragile X syndrome (FXS). To investigate these relationships, we conducted indirect functional assessments of aggressive behavior exhibited by 41 adolescent boys with FXS and 59 age and symptom-matched controls with intellectual and developmental disability (IDD) and compared the data between groups. Results showed that boys with FXS were more likely to exhibit specific forms of aggressive behavior (i.e., scratching others and biting others) compared to controls, but the sources of reinforcement identified for aggression were similar across groups. Boys with FXS who were prescribed psychotropic medications were more likely to be older and to exhibit more forms of aggression. The implications for the treatment of aggressive behavior during this critical developmental period in FXS are discussed.

Adaptive Status, Autistic Symptoms and Cognitive Profile in Patients with Monogenic Form of Autism Spectrum Disorders – Fragile X Syndrome

The article analyzes psychological data of a large group (55 males and 6 females) of subjects with monogenic form of hereditary cognitive impairment with autistic symptoms – Martin-Bell syndrome (FXS) at different age ranges (from 2 to 34 years old). As a result of the analysis, significant cognitive impairments were identified, which persisted throughout the studied age interval (IQ 50 ± 2.1 in males and 60 ± 5.6 in females). Autistic disorders were observed on average in 60% of subjects (less in females) and were most pronounced at 8-12 years. Use of Autism Diagnostic Observation Scale-2 (ADOS-2) allowed us to show that “Social Affect” scale makes the main contribution to overall score of autistic manifestations. Almost all subjects showed a significantly reduced level of adaptive skills. The lowest scores on “Communication”, “Socialization” and “Everyday life skills” scales were observed at the age of 8-12 years. With increase in age, subjects improved only on “Daily Life Skills” scale. It was also shown that a higher degree of adaptation and better nonverbal intelligence was observed in children with less severe autistic symptoms.

Social Avoidance Emerges in Infancy and Persists into Adulthood in Fragile X Syndrome

Fragile X syndrome (FXS) is characterized by both social approach and social avoidance. However, the age of emergence and developmental trajectory of social avoidance has not been examined. This study investigates the longitudinal developmental trajectory and dynamic nature of social avoidance in males with FXS from infancy through young adulthood (n = 191). Multiple facets of social avoidance were collected using the Social Avoidance Scale (Roberts et al. 2007, 2009). Overall, 81% of males with FXS displayed social avoidance, which emerged during infancy, increased in severity across childhood, and stabilized through adolescence and early adulthood. An exaggerated "warm up" effect was also observed in FXS. This study delineates the complex profile of social avoidance, a common and impairing behavioral feature of FXS.

Enriched Environments as a Potential Treatment for Developmental Disorders: A Critical Assessment

The beneficial effects of enriched environments have been established through a long history of research. Enrichment of the living conditions of captive animals in the form of larger cages, sensory stimulating objects, and opportunities for social interaction and physical exercise, has been shown to reduce emotional reactivity, ameliorate abnormal behaviors, and enhance cognitive functioning. Recently, environmental enrichment research has been extended to humans, in part due to growing interest in its potential therapeutic benefits for children with neurodevelopmental disorders (NDDs). This paper reviews the history of enriched environment research and the use of enriched environments as a developmental intervention in studies of both NDD animal models and children. We argue that while environmental enrichment may sometimes benefit children with NDDs, several methodological factors need to be more closely considered before the efficacy of this approach can be adequately evaluated, including: (i) operationally defining and standardizing enriched environment treatments across studies; (ii) use of control groups and better control over potentially confounding variables; and (iii) a comprehensive theoretical framework capable of predicting when and how environmental enrichment will alter the trajectory of NDDs.

A Description of the Educational Setting Among Individuals With Fragile X Syndrome

Children with fragile X syndrome (FXS) display wide-ranging intellectual and behavioral abilities that affect daily life. We describe the educational setting of students with FXS and assess the relationships between school setting, co-occurring conditions, and functional ability using a national survey sample ( n = 982). The majority of students with FXS in this sample have formal individualized education plans, spend part of the day outside regular classrooms, and receive modifications when in a regular classroom. Males with FXS and certain co-occurring conditions (autism, aggression, and self-injurious behavior) are more likely to spend the entire day outside regular classrooms, compared to males without these co-occurring conditions. Students who spend more time in regular classrooms are more likely to perform functional tasks without help.

Examining the influence of social-environmental variables on self-injurious behaviour in adolescent boys with fragile X syndrome

BACKGROUND

Individuals with fragile X syndrome (FXS), the most common known inherited form of intellectual disability, are at increased risk for showing specific forms of self-injurious behaviour (SIB) such as hand biting and head hitting, suggesting that biological factors associated with the syndrome confers increased risk for SIB. Few studies, however, have examined the extent to which social-environmental variables can influence the occurrence of these behaviours in this population.

METHOD

Twenty-two adolescent boys with FXS, aged 10 to 18 years were systematically exposed to seven environmental conditions in functional analyses of SIB conducted over 2 days at our research centre.

RESULTS

Fourteen (63.6%) boys with FXS engaged in SIB during the functional analyses. Ten (45.5%) boys engaged in SIB that was maintained by social-environmental variables, that is, gaining access to attention/tangibles and/or escaping from social interaction, task demands and/or transition demands. For two boys, SIB was undifferentiated across conditions, and for two boys, SIB appeared to be maintained by automatic reinforcement.

CONCLUSIONS

Social-environmental variables appeared to maintain SIB in a significant proportion of boys with FXS. Given that pharmacological treatments for SIB have limited efficacy in this population, the potential role of social-environmental factors on SIB should be examined before pharmacological treatments are implemented for these behaviours.

Distance delivery of a spoken language intervention for school-aged and adolescent boys with fragile X syndrome

A small randomized group design (N = 20) was used to examine a parent-implemented intervention designed to improve the spoken language skills of school-aged and adolescent boys with FXS, the leading cause of inherited intellectual disability. The intervention was implemented by speech-language pathologists who used distance video-teleconferencing to deliver the intervention. The intervention taught mothers to use a set of language facilitation strategies while interacting with their children in the context of shared story-telling. Treatment group mothers significantly improved their use of the targeted intervention strategies. Children in the treatment group increased the duration of engagement in the shared story-telling activity as well as use of utterances that maintained the topic of the story. Children also showed increases in lexical diversity, but not in grammatical complexity.

Problem behaviour in adolescent boys with fragile X syndrome: relative prevalence, frequency and severity

BACKGROUND

A large proportion of boys with fragile X syndrome (FXS), the most common known inherited form of intellectual disability (ID), exhibit problem behaviours (e.g. aggression, self-injury, property destruction and stereotypy) that can negatively impact the health and safety of others as well as the individual concerned. However, data are limited concerning the relative prevalence, frequency and severity of problem behaviours exhibited by boys with FXS compared with those by boys with mixed-aetiology ID who also exhibit problem behaviours.

METHOD

As part of a larger study on problem behaviour, we obtained survey data on 85 adolescent boys with FXS and 155 age-matched boys with mixed-aetiology ID who exhibited at least one form of problem behaviour.

RESULTS

For boys with FXS, stereotypy was reported to be more prevalent (χ²  = 4.52, P = 0.012), self-injury was reported to more frequent (U = 2525, P = 0.010) and aggression was reported to be less severe (U = 4176, P = 0.029) than for boys with mixed-aetiology ID. Ratings of aggression and property destruction were highly correlated in each group in terms of both frequency and severity (r = 0.60 to 0.71). Examination of the data by age indicated that the relative frequency of self-injury decreased with age in boys with FXS (χ²  = 8.29, P = 0.040).

CONCLUSIONS

Taken together, these results refine and extend previous studies concerning the specificity of the behavioural phenotype in FXS and indicate that specific forms of problem behaviour shown by boys with FXS appear to differ from those exhibited by boys with mixed-aetiology ID in terms of prevalence, frequency and severity. Studies employing more objective measures of frequency and severity, including direct observations, are needed to confirm these findings.

The relationship between autistic symptomatology and independent living skills in adolescents and young adults with fragile X syndrome

Few studies have examined the relationship between autistic symptomatology and competence in independent living skills in adolescents and young adults with fragile X syndrome (FXS). In this study, 70 individuals with FXS, aged 15-25 years, and 35 matched controls were administered direct measures of independent living skills and autistic symptomatology. Results showed that higher levels of autistic symptomatology were associated with lower levels of competence in independent living skills in individuals with FXS, but not in controls. These data indicated that the relationship between autistic symptomatology and independent living skills was syndrome-specific. Early intervention strategies that address autistic symptomatology are sorely needed to improve functional outcomes in this population.

A comparative study of educational provision for children with neurogenetic syndromes: parent and teacher survey

BACKGROUND

A number of neurogenetic syndromes have a high association with special educational needs including fragile X syndrome (FXS), Prader-Willi syndrome (PWS), Williams syndrome (WS) and Velo-Cardio-Facial syndrome (VCFS). There is a paucity of research on educational provision for children affected by these syndromes.

METHOD

Parents (n = 381) and teachers (n = 204) of school-aged children with one of the four syndromes in the UK and Ireland were surveyed in a range of areas concerning the child's educational provision. Areas surveyed included school placement, views on the needs of children with the syndromes, desired changes to current provision and perceived teacher knowledge.

RESULTS

School placement in mainstream settings decreased with age in all of the syndromes. Males with the syndromes were more likely to be in specialised educational settings with the exception of WS. Teachers reported limited input on initial or subsequent training for all of the syndromes. The majority of teachers did not view the needs of children with syndromes as different from other children with intellectual disability (ID) although there were significant differences between the syndromes. Changes deemed necessary to provision by parents and teachers differed between the syndromes indicating the existence of perceptions of syndrome specific needs. The lowest perceived level of teacher knowledge was in the VCFS group.

CONCLUSION

The majority of teachers of children with neurogenetic syndromes report limited knowledge of the syndromes, but also a lack of belief that the children's needs are different from the majority of children with ID. Differences between the syndromes in some areas of provision suggest that a child's syndrome does impact on educational provision in some areas.

Functional analysis and treatment of problem behavior exhibited by children with fragile X syndrome

The efficacy of function-based interventions for the treatment of severe problem behavior exhibited by individuals with intellectual and developmental disabilities (IDD) is well established. However, few studies have reported on behavioral interventions in fragile X syndrome (FXS) specifically. The present study is a consecutive case-series analysis that reports on functional analysis and treatment of problem behavior of nine children with FXS. Assessment findings were consistent with previous research indicating that among individuals with FXS, problem behavior is more commonly maintained by escape from demands and access to tangible items, relative to the broader population of individuals with IDD. Functional analysis-based behavioral interventions resulted in a mean reduction in problem behavior of 95.2% across the nine participants. Additionally, generalization of treatment effects from controlled clinical settings to home, school, and community was demonstrated. The current findings suggest that function-based behavioral interventions shown to be effective with the broader population of individuals with IDD are also effective for individuals with FXS. Our results in combination with those of previous studies describing functional analysis outcomes provide additional evidence for a unique functional behavioral phenotype for severe problem behavior in individuals with FXS. Implications of study findings for early intervention and prevention of problem behavior in children with FXS are discussed.

L-acetylcarnitine for treating fragile X syndrome

BACKGROUND

People with fragile X syndrome (FXS) have an intellectual dysfunction that can range from very mild to severe. Symptoms can include speech and language delays and behavioural difficulties such as aggression or self injurious behaviours, emotional lability, and anxiety-related problems (for example obsessive-compulsive symptoms and perseverative behaviours). In some cases, affected people may have an additional diagnosis of attention deficit hyperactivity disorder or an autism spectrum disorder.

OBJECTIVES

To review the efficacy and safety of L-acetylcarnitine in improving the psychological, intellectual, and social performance of people with FXS.

SEARCH METHODS

In May 2015 we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO, Web of Science, and two other databases. We also searched three trials registers, four theses databases, and the reference lists of relevant studies and reviews.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that assessed the efficacy of L-acetylcarnitine, at any dose, in people of any age diagnosed with FXS compared with placebo.

DATA COLLECTION AND ANALYSIS

For each trial, two review authors independently extracted data on the children included and interventions compared, and assessed the risk of bias of the studies across the following domains: randomisation sequence generation, allocation concealment, blinding (of participants, personnel, and outcome assessors), incomplete outcome data, selective outcome reporting, and other potential sources of bias.

MAIN RESULTS

We found only two RCTs that compared oral L-acetylcarnitine (LAC) with oral placebo in children with FXS. The studies included a total of 83 participants, all of them male, who were treated and followed for one year. The age of participants at the start of treatment ranged from 6 to 13 years, with a mean age of 9 years. Neither study provided information on randomisation, allocation concealment procedures, or blinding of outcome assessment, and we received no responses from the authors we emailed for clarification. We therefore rated studies as being at unclear risk of bias on these domains. We judged both studies to be at low risk of bias for blinding of participants and personnel, incomplete outcome data, and selective reporting, but to be at high risk of other bias, as at least one study was funded by a drug company, and in both studies people working for the company were part of the research team.We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate the quality of the available evidence. Overall, the quality of the evidence was low due to the imprecision of results and high risk of other bias.Regarding the primary outcome of psychological and learning capabilities, both studies assessed the effect of interventions on children's verbal and non-verbal intellectual functioning using the Wechsler Intelligence Scale for Children - Revised. The authors did not provide detailed data on those results but said that they found no important differences between treatment and placebo.Both studies evaluated the impact of the treatment on hyperactive behaviour using the Conners' Abbreviated Parent-Teacher Questionnaire. In one study, teachers' assessments of the children found no clear evidence of a difference (mean difference (MD) 0.50, 95% confidence interval (CI) -5.08 to 6.08, n = 51; low-quality evidence). The other study stated that there were no differences between treated and untreated participants, but did not provide detailed data for inclusion in the meta-analysis.Parents' assessments favoured LAC in one study (MD -0.57, 95% CI -0.94 to -0.19, n = 17; low-quality evidence), but not in the other (MD -2.80, 95% CI -7.61 to 2.01, n = 51; low-quality evidence), though changes were not large enough to be considered clinically relevant.Regarding social skills, one study reported no clear evidence of a difference in Vineland Adaptive Behavior composite scores (MD 8.20, 95% CI -0.02 to 16.42, n = 51; low-quality evidence), yet results in the socialisation domain favoured LAC (MD 11.30, 95% CI 2.52 to 20.08, n = 51; low-quality evidence).Both studies assessed the safety of the active treatment and recorded no side effects. Neither of the included studies assessed the secondary outcome of caregiver burden.

AUTHORS' CONCLUSIONS

Low-quality evidence from two small trials showed that when compared to placebo, LAC may not improve intellectual functioning or hyperactive behaviour in children with FXS.

An analysis of challenging behavior, comorbid psychopathology, and Attention-Deficit/Hyperactivity Disorder in Fragile X Syndrome

The present study sought to investigate the relationship between challenging behavior, comorbid psychopathology, and Attention-Deficit/Hyperactivity Disorder (AD/HD) in Fragile X Syndrome (FRAX). Additionally, this study sought to examine how such disorders are predicted by gender, presence of autism spectrum disorder (ASD), and presence of intellectual disability (ID). A total of 47 children and adolescents with FRAX were assessed. Results revealed high levels of challenging behavior and AD/HD symptoms within the sample, with some participants exhibiting symptoms of comorbid psychopathology. Further analysis revealed that challenging behavior and comorbid psychopathology were positively correlated, with stereotypy correlating most strongly with comorbid psychopathology. In addition, ASD was found to predict challenging behavior, and gender was found to predict AD/HD symptoms. The implications of these findings are discussed.

Uncovering the evidence for behavioral interventions with individuals with fragile X syndrome: a systematic review

Fragile X syndrome (FXS) is associated with a wide range of cognitive, emotional, and behavioral difficulties. Although there is considerable research on the behavioral phenotype of FXS, few empirical studies of behavioral interventions with this population have been identified. Through a hand search of 34 behavioral journals, we examined the evidence base for behavioral interventions with individuals with FXS and in light of the current state of knowledge regarding the FXS behavioral phenotype. Systematic review procedures were used to identify behavioral intervention studies that included at least one participant with FXS, extract and summarize the data on several relevant dimensions, and rate the methodological quality of the studies. Results revealed 31 intervention studies with a small number of participants with FXS. Overall, results suggest a behavioral approach to intervention with individuals with FXS shows promise. Future research focused on individuals with FXS will be necessary to continue to examine differences in response to intervention and interventions that specifically address phenotypic characteristics.

Providing a parent-implemented language intervention to a young male with fragile X syndrome: brief report

PURPOSE

Although fragile X syndrome (FXS) is the leading inherited cause of intellectual disability, there are no published intervention studies focused on improving communication and language outcomes for affected children. The current study utilized a collaborative coaching approach incorporating strategies from speech-language pathology and applied behavior analysis to examine the efficacy of a naturalistic parent-implemented language intervention for a young boy with FXS.

METHODS

The mother was taught the language and behavioral support strategies and submitted weekly video recordings of a caregiving routine. Written feedback was provided.

RESULTS

Results indicated moderate increases in maternal use of targeted language support strategies and variable performance in maternal use of behavior support strategies. Child use of appropriate requests increased while challenging behaviors decreased.

CONCLUSIONS

This collaborative approach model should be used to guide future larger scale replications and develop new intervention models.

Clinical, molecular, and pharmacological aspects of FMR1 related disorders

BACKGROUND

Fragile X syndrome, the most common inherited cause of intellectual disability, is associated with a broad spectrum of disorders across different generations of a single family. This study reviews the clinical manifestations of fragile X-associated disorders as well as the spectrum of mutations of the fragile X mental retardation 1 gene (FMR1) and the neurobiology of the fragile X mental retardation protein (FMRP), and also provides an overview of the potential therapeutic targets and genetic counselling.

DEVELOPMENT

This disorder is caused by expansion of the CGG repeat (>200 repeats) in the 5 prime untranslated region of FMR1, resulting in a deficit or absence of FMRP. FMRP is an RNA-binding protein that regulates the translation of several genes that are important in synaptic plasticity and dendritic maturation. It is believed that CGG repeat expansions in the premutation range (55 to 200 repeats) elicit an increase in mRNA levels of FMR1, which may cause neuronal toxicity. These changes manifest clinically as developmental problems such as autism and learning disabilities as well as neurodegenerative diseases including fragile X-associated tremor/ataxia syndrome (FXTAS).

CONCLUSIONS

Advances in identifying the molecular basis of fragile X syndrome may help us understand the causes of neuropsychiatric disorders, and they will probably contribute to development of new and specific treatments.

Oxytocin and vasopressin systems in genetic syndromes and neurodevelopmental disorders

Oxytocin (OT) and arginine vasopressin (AVP) are two small, related neuropeptide hormones found in many mammalian species, including humans. Dysregulation of these neuropeptides have been associated with changes in behavior, especially social interactions. We review how the OT and AVP systems have been investigated in Autism Spectrum Disorder (ASD), Prader-Willi Syndrome (PWS), Williams Syndrome (WS) and Fragile X syndrome (FXS). All of these neurodevelopmental disorders (NDD) are marked by social deficits. While PWS, WS and FXS have identified genetic mutations, ASD stems from multiple genes with complex interactions. Animal models of NDD are invaluable for studying the role and relatedness of OT and AVP in the developing brain. We present data from a FXS mouse model affecting the fragile X mental retardation 1 (Fmr1) gene, resulting in decreased OT and AVP staining cells in some brain regions. Reviewing the research about OT and AVP in these NDD suggests that altered OT pathways may be downstream from different etiological factors and perturbations in development. This has implications for ongoing studies of the therapeutic application of OT in NDD. This article is part of a Special Issue entitled Oxytocin and Social Behav.

Identifying large-scale brain networks in fragile X syndrome

IMPORTANCE

Fragile X syndrome (FXS) is an X-linked neurogenetic disorder characterized by a cognitive and behavioral phenotype resembling features of autism spectrum disorder. Until now, research has focused largely on identifying regional differences in brain structure and function between individuals with FXS and various control groups. Very little is known about the large-scale brain networks that may underlie the cognitive and behavioral symptoms of FXS.

OBJECTIVE

To identify large-scale, resting-state networks in FXS that differ from control individuals matched on age, IQ, and severity of behavioral and cognitive symptoms.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional, in vivo neuroimaging study conducted in an academic medical center. Participants (aged 10-23 years) included 17 males and females with FXS and 16 males and females serving as controls.

MAIN OUTCOMES AND MEASURES

Univariate voxel-based morphometric analyses, fractional amplitude of low-frequency fluctuations (fALFF) analysis, and group-independent component analysis with dual regression.

RESULTS

Patients with FXS showed decreased functional connectivity in the salience, precuneus, left executive control, language, and visuospatial networks compared with controls. Decreased fALFF in the bilateral insular, precuneus, and anterior cingulate cortices also was found in patients with FXS compared with control participants. Furthermore, fALFF in the left insular cortex was significantly positively correlated with IQ in patients with FXS. Decreased gray matter density, resting-state connectivity, and fALFF converged in the left insular cortex in patients with FXS.

CONCLUSIONS AND RELEVANCE

Fragile X syndrome results in widespread reductions in functional connectivity across multiple cognitive and affective brain networks. Converging structural and functional abnormalities in the left insular cortex, a region also implicated in individuals diagnosed with autism spectrum disorder, suggests that insula integrity and connectivity may be compromised in FXS. This method could prove useful in establishing an imaging biomarker for FXS.

Biobehavioral indicators of social fear in young children with fragile X syndrome

Anxiety is among the most impairing conditions associated with Fragile X syndrome (FXS) and is putatively linked to atypical physiological arousal. However, few studies have examined this association in young children with FXS. The authors examined whether patterns of arousal and behavior during an experimental stranger approach paradigm differ between a cross-sectional sample of 21 young children with FXS and 19 controls (12-58 months old). Groups did not differ in mean levels of behavioral fear. Unlike the control group, however, the FXS group demonstrated increased facial fear at older ages, as well as age-dependent changes in associations between heart activity and distress vocalizations. These findings may inform theoretical models of anxiety etiology in FXS and early detection efforts.

Knowledge and perceptions about fragile X syndrome: implications for diagnosis, intervention, and research

We surveyed 439 professionals in the field of autism to assess their knowledge and perceptions about fragile X syndrome (FXS) and related issues. Almost half had worked with at least one child diagnosed with FXS, yet most lacked basic knowledge about the condition, underestimated its significance in the etiology of autism spectrum disorders, and rarely accessed fragile X-specific resources. A majority perceived etiology to be an important variable in therapeutic response while three quarters felt that professionals in the field of autism should play an active role in referring children for etiological evaluation. Despite these opinions, most respondents either rarely or never inquired about etiology when working with a new client. The survey results underscore the need for training and education so that autism professionals can become effective partners in diagnostic genetic referral and in research and implementation of syndrome-specific interventions.

Early negative affect predicts anxiety, not autism, in preschool boys with fragile X syndrome

Children with fragile X syndrome (FXS) face high risk for anxiety disorders, yet no studies have explored FXS as a high-risk sample for investigating early manifestations of anxiety outcomes. Negative affect is one of the most salient predictors of problem behaviors and has been associated with both anxiety and autistic outcomes in clinical and non-clinical pediatric samples. In light of the high comorbidity between autism and anxiety within FXS, the present study investigates the relationship between longitudinal trajectories of negative affect (between 8 and 71 months) and severity of anxiety and autistic outcomes in young males with FXS (n = 25). Multilevel models indicated associations between elevated anxiety and higher fear and sadness, lower soothability, and steeper longitudinal increases in approach. Autistic outcomes were unrelated to negative affect. These findings suggest early negative affect differentially predicts anxiety, not autistic symptoms, within FXS. Future research is warranted to determine the specificity of the relationship between negative affect and anxiety, as well as to explore potential moderators. Characterizing the relationship between early negative affect and anxiety within FXS may inform etiology and treatment considerations specific to children with FXS, as well as lend insight into precursors of anxiety disorders in other clinical groups and community samples.

Behaviour problems, maternal internalising symptoms and family relations in families of adolescents and adults with fragile X syndrome

BACKGROUND

Studies have linked the behaviour problems of children with fragile X syndrome (FXS) to maternal well-being, but less is known about how behaviour problems relate to important family factors such as marital satisfaction and family cohesion.

METHODS

Married mothers of 115 adolescents and adults with FXS completed questionnaires and interviews, and maternal CGG repeat length was obtained by medical/laboratory records or by blood analysis.

RESULTS

Indirect effects were present between behaviour problems and family variables in that behaviour problems were positively related to maternal internalising symptoms which were, in turn, negatively associated with both family cohesion and marital satisfaction. Direct associations between behaviour problems and family relationship variables were not significant.

CONCLUSIONS

Findings suggest the importance of intervening with behaviour problems in individuals with FXS and identify maternal mental health as a potentially powerful conduit for the effects of child behaviour on relationships within these families. Implications for targeted interventions are discussed.

A 'learning platform' approach to outcome measurement in fragile X syndrome: a preliminary psychometric study

BACKGROUND

Clinical trials of medications to alleviate the cognitive and behavioural symptoms of individuals with fragile X syndrome (FXS) are now underway. However, there are few reliable, valid and/or sensitive outcome measures available that can be directly administered to individuals with FXS. The majority of assessments employed in clinical trials may be suboptimal for individuals with intellectual disability (ID) because they require face-to-face interaction with an examiner, taxing administration periods, and do not provide reinforcement and/or feedback during the test. We therefore examined the psychometric properties of a new computerised 'learning platform' approach to outcome measurement in FXS.

METHOD

A brief computerised test, incorporated into the Discrete Trial Trainer©- a commercially available software program designed for children with ID - was administered to 13 girls with FXS, 12 boys with FXS and 15 matched ID controls aged 10 to 23 years (mental age = 4 to 12 years). The software delivered automated contingent access to reinforcement, feedback, token delivery and prompting procedures (if necessary) on each trial to facilitate responding. The primary outcome measure was the participant's learning rate, derived from the participant's cumulative record of correct responses.

RESULTS

All participants were able to complete the test and floor effects appeared to be minimal. Learning rates averaged approximately five correct responses per minute, ranging from one to eight correct responses per minute in each group. Test-retest reliability of the learning rates was 0.77 for girls with FXS, 0.90 for boys with FXS and 0.90 for matched ID controls. Concurrent validity with raw scores obtained on the Arithmetic subtest of the Wechsler Intelligence Scale for Children-III was 0.35 for girls with FXS, 0.80 for boys with FXS and 0.56 for matched ID controls. The learning rates were also highly sensitive to change, with effect sizes of 1.21, 0.89 and 1.47 in each group respectively following 15 to 20, 15-min sessions of intensive discrete trial training conducted over 1.5 days.

CONCLUSIONS

These results suggest that a learning platform approach to outcome measurement could provide investigators with a reliable, valid and highly sensitive measure to evaluate treatment efficacy, not only for individuals with FXS but also for individuals with other ID.

Behavioural phenotypes and special educational needs: is aetiology important in the classroom?

BACKGROUND

A number of genetic conditions with associated intellectual disability and/or special educational needs have increasingly well-defined behavioural phenotypes. Thus, the concept of 'behavioural phenotype' and aetiology of intellectual disability may be important with regard to school-based interventions.

METHOD

The evidence for distinctive cognitive and behavioural aspects of five of the most common genetic syndromes (Down syndrome, fragile X syndrome, Williams syndrome, Prader-Willi syndrome and velo-cardio-facial syndrome) associated with special educational needs is reviewed with respect to key studies and findings. The possible utility of aetiology-related interventions in education is discussed with reference to arguments for and against such approaches with respect to published guidelines and published research.

RESULTS

Behavioural phenotypes are probabilistic and many children with a specific genetic syndrome will share commonalities with other children with other genetic syndromes and within syndrome variability is not uncommon. There is evidence that teachers and parents have limited knowledge of aspects of the proposed cognitive and behaviour profiles associated with the reviewed syndromes. While there are published guidelines in the area of learning and behaviour for each of the five reviewed syndromes there is a limited amount of evidence of the efficacy of such approaches in school settings.

CONCLUSION

It is likely that knowing the aetiology of a child's special educational needs will be helpful for staff who work in school settings in relation to cognitive and behavioural implications. However, how such knowledge might inform teaching practice or behavioural interventions has not been studied. A model is proposed that might help inform educators about the possible role of aetiology in the classroom.

Reward circuitry dysfunction in psychiatric and neurodevelopmental disorders and genetic syndromes: animal models and clinical findings

This review summarizes evidence of dysregulated reward circuitry function in a range of neurodevelopmental and psychiatric disorders and genetic syndromes. First, the contribution of identifying a core mechanistic process across disparate disorders to disease classification is discussed, followed by a review of the neurobiology of reward circuitry. We next consider preclinical animal models and clinical evidence of reward-pathway dysfunction in a range of disorders, including psychiatric disorders (i.e., substance-use disorders, affective disorders, eating disorders, and obsessive compulsive disorders), neurodevelopmental disorders (i.e., schizophrenia, attention-deficit/hyperactivity disorder, autism spectrum disorders, Tourette's syndrome, conduct disorder/oppositional defiant disorder), and genetic syndromes (i.e., Fragile X syndrome, Prader-Willi syndrome, Williams syndrome, Angelman syndrome, and Rett syndrome). We also provide brief overviews of effective psychopharmacologic agents that have an effect on the dopamine system in these disorders. This review concludes with methodological considerations for future research designed to more clearly probe reward-circuitry dysfunction, with the ultimate goal of improved intervention strategies.

Effects of intranasal oxytocin on social anxiety in males with fragile X syndrome

Fragile X syndrome (FXS) is a rare inherited genetic disorder causing severe intellectual disability and autistic-like symptoms. Individuals with FXS, males in particular, often exhibit extreme eye gaze avoidance and hyperarousal when they encounter stressful social situations. We investigated whether oxytocin (OT), a hormone with prosocial and anxiolytic effects, could alleviate symptoms of social anxiety in this population. A randomized double-blind placebo-controlled single-dose trial was performed with intranasal administration of placebo, 24 IU OT and 48 IU OT. Measures of eye gaze frequency, heart rate, respiratory sinus arrhythmia (RSA), heart rate variability (HRV) and salivary cortisol were obtained during a structured social challenge conducted 50 min following OT administration. Ten low-functioning males with FXS (aged 13-28 years) traveled to Stanford for the initial visit: 8 completed the study. Eye gaze frequency improved significantly in response to the 24 IU OT dose and salivary cortisol levels decreased significantly in response to the 48 IU OT dose. There was no effect of OT on heart rate, RSA or HRV although individual plots of the heart rate data suggested that OT increased heart rate in some participants and decreased heart rate in others. These findings suggest that intranasal administration of OT may ameliorate some symptoms of social anxiety in patients with FXS. Further double-blind placebo-controlled studies of OT, conducted in combination with behavioral treatment programs, may be warranted.

Medication utilization for targeted symptoms in children and adults with fragile X syndrome: US survey

OBJECTIVE

To identify the most common neurological and behavioral symptoms treated by medications in individuals with fragile X syndrome (FXS), factors associated with treatment variability, and difficulty in swallowing a pill.

METHOD

A total of 1019 caregivers provided information about 1064 sons and 299 daughters with FXS in a US national survey. Caregivers reported (a) current use of medications for attention, anxiety, hyperactivity, mood swings, anger, depression, seizures, self-injury, or sleep; (b) perceived efficacy; and (c) difficulty in swallowing a pill.

RESULTS

Sixty-one percent of males and 38% of females were currently taking medication for at least 1 symptom. The most common symptoms were anxiety, attention, and hyperactivity. Treatments for attention and hyperactivity were common in childhood but declined substantially after the age of 18 years; anxiety treatment remained high in adults. Children perceived to be more impaired and children diagnosed or treated for autism were more likely to be taking medications. Caregivers considered most medications somewhat effective, but less than one-third rated current medication as "a lot" effective. Many children had difficulty swallowing a pill, but only 11% of adult males and 2% of adult females had a lot of difficulty.

CONCLUSION

Symptom-based medication use is common in FXS, although response is incomplete and there is clearly an unmet need for medications with improved efficacy. The persistent use of medications to treat anxiety, mood, and behavior problems throughout adolescence and into the adult years suggests important outcomes when evaluating the efficacy of new medications.

Behavioral intervention for problem behavior in children with fragile X syndrome

Parents and professionals typically report problem behavior as a significant concern for children with fragile X syndrome. In the present study, the authors explored whether behaviorally based interventions would result in a reduction in problem behavior and an improvement in quality of life for 3 children with fragile X syndrome and their families. A multiple baseline design was used to demonstrate intervention effects for specific high-priority contexts (i.e., bedtime, running errands, and toileting). A multicomponent intervention plan was developed to teach the parents and child to effectively cope with the particular context. After intervention, there were substantial improvements in problem behavior and family quality of life within the given contexts. Results of this study demonstrated the effectiveness of behavioral intervention for children with fragile X syndrome.

Folic acid for fragile X syndrome

BACKGROUND

It has been argued that individuals with fragile X syndrome could have low folate levels in their bodies and that supplementing their dietary intake might remediate the adverse developmental and behavioural effects of the condition.

OBJECTIVES

To review the efficacy and safety of folic acid in the treatment of people with fragile X syndrome.

SEARCH STRATEGY

We searched four databases in November 2010: CENTRAL, PubMed, EMBASE and PsycINFO.

SELECTION CRITERIA

Randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias using the Cochrane 'Risk of bias' tool.

MAIN RESULTS

We included five trials, which were published between 1986 and 1992. Overall, they included 67 patients, all male, with ages ranging from one to 54 years. Intellectual disability in participants varied from borderline to severe and some studies included patients with an additional diagnosis of autism or autistic behaviour. Four of the studies were placebo-controlled cross-over trials and one study was a parallel design. The duration of follow-up ranged from two months to 12 months and the period on folic acid or placebo ranged from two to eight months. Doses of folic acid ranged from 10 mg to 250 mg per day, 10 mg per day being the most common. Most of the younger patients involved were also taking part in special education programmes (usually involving language and occupational therapy).We were not able to perform meta-analysis to combine results but none of the individual studies found evidence of clinical benefit with the use of folic acid medication in fragile X syndrome patients on any of the areas of interest, either psychological and learning capabilities or behaviour and social performance, as measured with standardised tools. Separate analysis of evidence for patients of different age groups, i.e. prepubertal children and postpubertal young people, found some statistically significant results, but did not show clear evidence of benefit for either group. Adverse effects of folic acid treatment were rare, not serious and transient.Studies were generally poorly reported and we classified only one study as being at low risk of bias.

AUTHORS' CONCLUSIONS

The quality of available evidence is low and not suitable for drawing conclusions about the effect of folic acid on fragile X syndrome patients. It consists of few studies with small samples of patients, all of them male, with little statistical power to detect anything other than huge effects.

Dysregulation of fragile × mental retardation protein and metabotropic glutamate receptor 5 in superior frontal cortex of individuals with autism: a postmortem brain study

Background

Fragile X syndrome is caused by loss of function of the fragile X mental retardation 1 (FMR1) gene and shares multiple phenotypes with autism. We have previously found reduced expression of the protein product of FMR1 (FMRP) in vermis of adults with autism.

Methods

In the current study, we have investigated levels of FMRP in the superior frontal cortex of people with autism and matched controls using Western blot analysis. Because FMRP regulates the translation of multiple genes, we also measured protein levels for downstream molecules metabotropic glutamate receptor 5 (mGluR5) and γ-aminobutyric acid (GABA) A receptor β3 (GABRβ3), as well as glial fibrillary acidic protein (GFAP).

Results

We observed significantly reduced levels of protein for FMRP in adults with autism, significantly increased levels of protein for mGluR5 in children with autism and significantly increased levels of GFAP in adults and children with autism. We found no change in expression of GABRβ3. Our results for FMRP, mGluR5 and GFAP confirm our previous work in the cerebellar vermis of people with autism.

Conclusion

These changes may be responsible for cognitive deficits and seizure disorder in people with autism.

Examining the function of problem behavior in fragile X syndrome: preliminary experimental analysis

Fragile X syndrome is the most common inherited cause of intellectual and developmental disability. The influence of environmental variables on behaviors associated with the syndrome has received only scant attention. The current study explored the function served by problem behavior in fragile X syndrome by using experimental functional analysis methodology with 8 children with fragile X. No child met criteria for attention-maintained problem behavior, 5 children met criteria for escape-maintained problem behavior, and 4 children met criteria for tangible-maintained problem behavior. Results are discussed and compared with previous findings on the function of problem behavior in fragile X syndrome, and implications for intervention are discussed. It is noted that the external validity of these findings is limited by the small sample size.

Autism in fragile X syndrome: a category mistake?

OBJECTIVE

Many investigators now routinely classify children with fragile X syndrome (FXS) according to whether or not they also meet diagnostic criteria for autism. To determine whether this classification is appropriate, we examined the profiles of autistic behaviors shown by boys and girls with FXS.

METHOD

Individuals with FXS, aged 5 to 25 years, were assessed on two established measures of autism, the Social Communication Questionnaire (SCQ) and the Autism Diagnostic Observation Schedule (ADOS).

RESULTS

We found that 35.1% of boys and 4.3% of girls with FXS scored in the "autism" category on both instruments. Analysis of the symptom profile indicated that both boys and girls with FXS showed lower rates of impairment on communication and reciprocal social interaction items than the reference autism samples on the measures. Furthermore, a regression model showed that IQ was significantly negatively associated with the SCQ total score in both boys and girls with FXS, when controlling for age, medication use, and FMRP levels.

CONCLUSIONS

These data suggest that there are significant differences in the profile of social and communicative symptomatology in FXS compared with individuals diagnosed with idiopathic autism. Given these differences, the implementation of standard autism interventions for individuals with FXS may not be optimal. Maintaining the conceptual distinction between FXS (an established biological disease) and idiopathic autism (a phenomenologically defined behavioral disorder) may also facilitate the development of more targeted and thus effective interventions for individuals with FXS in the future.