Acoustic properties of early vocalizations in infants with fragile X syndrome

Abstract

Fragile X syndrome (FXS) is a neurogenetic syndrome characterized by cognitive impairments and high rates of autism spectrum disorder (ASD). FXS is often highlighted as a model for exploring pathways of symptom expression in ASD due to the high prevalence of ASD symptoms in this population and the known single‐gene cause of FXS. Early vocalization features—including volubility, complexity, duration, and pitch—have shown promise in detecting ASD in idiopathic ASD populations but have yet to be extensively studied in a population with a known genetic cause for ASD such as FXS. Investigating early trajectories of these features in FXS may inform our limited knowledge of potential mechanisms that predict later social communication outcomes. The present study addresses this need by presenting preliminary findings which (a) characterize early vocalization features in FXS relative to low‐risk controls (LRC) and (b) test the specificity of associations between these features and language and ASD outcomes. We coded vocalization features during a standardized child–examiner interaction for 39 nine‐month‐olds (22 FXS, 17 LRC) whose clinical outcomes were assessed at 24 months. Our results provide preliminary evidence that within FXS, associations between vocalization features and 24‐month language outcomes may diverge from those observed in LRC, and that vocalization features may be associated with later ASD symptoms. These findings provide a starting point for more research exploring these features as potential early markers of ASD in FXS, which in turn may lead to improved early identification methods, treatment approaches, and overall well‐being of individuals with ASD. Autism Res2019. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryAlthough vocal features of 9‐month‐olds with FXS did not differ from those of low‐risk controls, several features were associated with later language and ASD outcomes at 24 months in FXS. These preliminary results suggest acoustic data may be related to clinical outcomes in FXS and potentially other high‐risk populations. Further characterizing these associations may facilitate understanding of biological mechanisms and risk factors associated with social communication development and ASD.

Early communication development in infants and toddlers with Fragile X syndrome

“…Further, infants and toddlers with FXS Only outperformed those with FXS + autism in all CSBS-CQ domains and subdomains, except for the Words subdomain. These findings are consistent with other studies of early communication in FXS that have noted greater delays in early communication/language are related to increased likelihood of autism or the later diagnosis of autism ( Hahn et al, 2017 ; Hamrick et al, 2019 ; McDuffie et al, 2012 ; Philofsky et al, 2004 ; Rague et al, 2018 ; Thurman et al, 2017 ).…”

“…Only one study has explored the relationship between early vocalizations and the presence of autism in FXS, despite emerging evidence for this association in children with nonsyndromic autism. Consistent with findings in children with nonsyndromic autism (Fusaroli et al, 2017), infants with FXS who had higher pitch vocalizations (i.e., atypical pitch) at 9-months had more autism symptoms at 24 months ( Hamrick et al, 2019 ). Despite the limited research on vocalizations in infants and toddlers with FXS, vocalizations and babbling support the development of spoken language (i.e., first words) and continue to support communication throughout the life course in typically developing children and children with other neurodevelopmental disorders.…”

Using big data from long-form recordings to study development and optimize societal impact

“…There remain, however, several roadblocks to measuring infant vocalizations for diagnosis. For one thing, one characteristic common to infants who eventually receive diagnoses of speech-language or neuro-developmental disorders, such as childhood apraxia of speech, ASD, or neurogenetic syndromes associated with ASD like fragile X syndrome, is the infrequency or near absence of vocalizations in infancy (Belardi et al, 2017;Hamrick, Seidl, & Tonnsen, 2019;Overby, Belardi, & Schreiber, 2020;Patten et al, 2014;Warlaumont, Richards, Gilkerson, & Oller, 2014). Logically, if an infant is not vocalizing, clinicians cannot evaluate the vocalization structure.…”

Automatic vocalisation-based detection of fragile X syndrome and Rett syndrome

“…In a study comparing the (pre-)linguistic development of 10 individuals with FXS and 14 typically developing (TD) individuals at 9–12 months of age, Belardi and colleagues 37 reported a reduced number of produced syllables per time and a reduced proportion of produced canonical syllables for the individuals with FXS. Preliminary results by Hamrick and colleagues 38 on a group of 22 individuals with FXS and a group of 17 TD controls indicate that, associations between selected characteristics of verbal behaviour at 9 months, such as the mean fundamental frequency ( ) or range, and language outcomes at 24 months might differ between the groups. In a longitudinal study on 15 individuals with RTT over the first 2 years of life by Marschik and colleagues 39 , some individuals were found not to acquire certain (pre-)linguistic capacities, such as the reduplication of canonical syllables or the production of (proto-)words.…”