Growth of Expressive Syntax in Children With Fragile X Syndrome

Abstract

Purpose: This research explored syntactic growth in children with fragile X syndrome (FXS) over a 5-year period, and variability in growth in relation to autism symptoms, nonverbal cognition, maternal responsivity, and gender. Method: Language samples at 4 time points from 39 children with FXS, 31 boys and 8 girls, were analyzed using the Index of Productive Syntax (Scarborough, 1990) and mean length of utterance (Brown, 1973). The degree of autism symptoms was evaluated using the Childhood Autism Rating Scale (Schopler, Reichler, & Renner, 1988) at the first time point. Maternal responsivity estimates were averaged across time points. Results: Children with FXS showed significant syntactic growth over time and a significant plateau (quadratic trend) in the later observations. Children who exhibited more autism symptoms at Time 1 had significantly lower syntactic abilities over time than children who exhibited fewer autism symptoms. Nonverbal cognition significantly predicted mean length of utterance scores but not Index of Productive Syntax scores. Maternal responsivity was not a significant predictor of syntactic outcomes. Girls with FXS generally demonstrated better expressive syntax than boys with FXS with notable individual differences. Conclusion: Despite significant growth over time, expressive syntax is a vulnerable domain for children with FXS, especially for those with severe autism symptoms. Clinical implications arising from the current findings are discussed.

Expressive language development in adolescents with Down syndrome and fragile X syndrome: change over time and the role of family-related factors

“…The syntactic complexity of expressive language is more limited in males with FXS than would be expected based on MA, and this finding is relatively consistent across multiple methods of assessment [28,[42][43][44]. Expressive pragmatics also appears to be an area of special weakness in FXS, including frequent off-topic and tangential utterances [44,45], omission of critical story elements in narratives [42], and verbal perseveration (i.e., excessive repetition) of a word, phrase, or topic [46].…”

Language across the Lifespan in Fragile X Syndrome: Characteristics and Considerations for Assessment

“…As clinical trials continue to increase in these populations so does the need for valid outcome measures. Possibilities for alternative assessment tools could include dynamic assessment (in which the assessment task is modified during testing depending on the participant's abilities) and communication sampling (which provides a more naturalistic view of communication abilities), both of which are appropriate for a wide range of language abilities [34,35]. Future research should continue to explore alternative means of deriving scores, as well as the development of standardized outcome measures that are appropriate for a wide range of language abilities.…”

“…This is likely due to the delay that has been well-documented in both cognitive and language development that becomes more apparent as the individuals enter into adolescence and adulthood. At this time, whereas individuals who are neurotypical undergo rapid growth in these areas, individuals with FXS have a much slower rate of growth and some evidence a plateau in development [34]. This is apparent in both the males and females, as the discrepancy between chronological age and age equivalent scores increases with age.…”

Language Development From Early Childhood to Adolescence in Youths With Fragile X Syndrome

“…Most males and many females with FXS have impaired communication (Abbeduto et al, 2016). Impairments have been reported in the areas of speech intelligibility (Barnes et al, 2009), vocabulary (Roberts et al, 2007;Sudhalter & Belser, 2001), morphology and syntax (Komesidou et al, 2017;Martin et al, 2013), and pragmatics (Martin et al, 2018). In addition, individuals with FXS have impaired cognition, and there is a relationship between the amount of impairments in cognition and communication (Abbeduto et al, 2007;Oakes et al, 2013).…”