Trajectories and Predictors of the Development of Very Young Boys with Fragile X Syndrome

Department of Psychology, University of South Carolina, Barnwell College, Columbia, SC 29208, USA.
Journal of Pediatric Psychology (Impact Factor: 2.91). 09/2009; 34(8):827-36. DOI: 10.1093/jpepsy/jsn129
Source: PubMed


To describe the development of young boys with fragile X syndrome (FXS).
Fifty-five boys (aged 8-48 months at study entry) with the full mutation FXS received multiple developmental assessments.
As expected, the boys' rate of development was significantly lower than chronological age expectations. No evidence of slowing in the rate of development was found. Autistic behavior was negatively associated with development, but maternal IQ was not. Developmental delays were evident in some domains as early as 9 months; however, initial detection of delays is complicated by measures and criteria used. Developmental age scores at 31 months of age were related to scores obtained at 61 months of age only in the global composite and visual reception domain.
Developmental delays are evident in some infants with FXS as young as 9 months of age. Pediatric psychologists need to be informed about the developmental profiles in young children with FXS to accurately diagnose, treat, and support these children and their families.

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    • "It is paradoxical that, given the tremendous richness of data that accrues from using longitudinal methodology, relatively few studies have chosen this pathway. From these few studies, there is already emerging evidence to indicate a dynamic cognitive profile in children with FXS for social cognition (Hernandez et al., 2009), adaptive functioning (Roberts et al., 2009) and general intelligence (Hall et al., 2008). Our data extends this research by suggesting that in FXS attentional control and WM clearly do not index developmental freeze: if followed longitudinally, even across two time points, children with the condition show improvements in performance that were not either captured by cross-sectional comparisons or by teacher-reported behavioral scores. "
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    ABSTRACT: Fragile X syndrome (FXS) has a characteristic cognitive "signature" that by late childhood includes core weaknesses in attention and working memory (WM), but their earlier developmental trajectories remain uncharted. Using a combined cross-sectional and prospective longitudinal design, we tested whether early profiles of attention and WM impairment in FXS indicate developmental freeze or developmental change. In Study 1, 26 young boys with FXS and 55 typically developing (TD) boys completed two experimental paradigms designed to assess cognitive aspects of attention and WM, in addition to behavioral indices of inattention and hyperactivity. Study 2 mapped longitudinal changes in 21 children with FXS and 21 TD children. In Study 1, significant weaknesses emerged for boys with FXS, with no substantial improvement over chronological age. Mapping performance against mental age level revealed delay, but it also yielded a similar attention and WM profile to TD boys. In Study 2, longitudinal improvements for boys with FXS paralleled those in TD children. In conclusion, cognitive attention and WM, although delayed in FXS, reveal developmental change, rather than "arrest." Our findings underscore the need for going beyond cross-sectional group comparisons and gross behavioral indices to map cognitive changes longitudinally in developmental disorders.
    Development and Psychopathology 05/2013; 25(2):365-76. DOI:10.1017/S0954579412001113 · 4.89 Impact Factor
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    • "Typically, the developmental trajectory in children with FXS is approximately 50% of the normal rate and expressive language is even lower [50]. A recent study reports that developmental delays in receptive and expressive language domains were evident by 9 month of age in children with FXS [51]. Language is an important domain because it most strongly correlates with intellectual ability. "
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    ABSTRACT: Young children with fragile X syndrome (FXS) often experience anxiety, irritability, and hyperactivity related to sensory hyperarousal. However, there are no medication recommendations with documented efficacy for children under 5 years old of age with FXS. We examined data through a chart review for 45 children with FXS, 12-50 months old, using the Mullen Scales of Early Learning (MSEL) for baseline and longitudinal assessments. All children had clinical level of anxiety, language delays based on MSEL scores, and similar early learning composite (ELC) scores at their first visit to our clinic. Incidence of autism spectrum disorder (ASD) was similar in both groups. There were 11 children who were treated with sertraline, and these patients were retrospectively compared to 34 children who were not treated with sertraline by chart review. The baseline assessments were done at ages ranging from 18 to 44 months (mean 26.9, SD 7.99) and from 12 to 50 months (mean 29.94, SD 8.64) for treated and not treated groups, respectively. Mean rate of improvement in both expressive and receptive language development was significantly higher in the group who was treated with sertraline (P < 0.0001 and P = 0.0071, resp.). This data supports the need for a controlled trial of sertraline treatment in young children with FXS.
    05/2012; 2012:104317. DOI:10.1155/2012/104317
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    • "Children with FXS as young as 9 months of age exhibit delays in development that continue throughout childhood and adolescence (J. E. Roberts et al., 2009). Cognitive and language development of children with FXS occurs at a significantly slower pace than that of children with TD (Hall, Burns, Lightbody, & Reiss, 2008; Prouty et al., 1988). "
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    ABSTRACT: To gain a better understanding of language abilities, the expressive macrostructural narrative language abilities of verbally expressive adolescents and young adults with Down syndrome (DS) and those with fragile X syndrome (FXS) were examined. The authors evaluated 24 adolescents and young adults with DS, 12 male adolescents and young adults with FXS, and 21 younger children with typical development (TD). Narrative samples were assessed at the macrostructural level using the narrative scoring scheme (Heilmann, Miller, Nockerts, & Dunaway, 2010). Three group comparisons were made using (a) the full sample matched on nonverbal mental age, (b) a subset of the participants individually matched on nonverbal mental age, and (c) a subset of participants individually matched on mean length of utterance. Study analyses revealed that the DS and FXS groups significantly outperformed the TD group on a limited number of narrative scoring scheme measures. No significant differences emerged between the DS and FXS groups. The study's results suggest that some aspects of macrostructural narrative language may be relative strengths for adolescents and young adults with DS and those with FXS. These results can be used to create more nuanced and informed approaches to assessment and intervention for these populations.
    American Journal of Speech-Language Pathology 11/2011; 21(1):29-46. DOI:10.1044/1058-0360(2011/10-0095) · 1.59 Impact Factor
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