Early developmental trajectories of expressive vocabulary and gesture production in a longitudinal cohort of Italian infants at high-risk for Autism Spectrum Disorder.
Tracking both words and gestures from 12 to 18 months picks out high-risk infants who will show the most ASD symptoms by age two.
01Research in Context
What this study did
Valentina and colleagues watched a group of Italian infants who have an older sibling with autism. These babies are at high risk for ASD.
The team tracked how many words each baby said and how many gestures each baby made every month from 12 to 18 months. They then scored ASD symptoms at age two.
What they found
Babies who stayed low in both words and gestures across the six-month window later showed the most ASD symptoms.
Babies whose vocabulary or gesture use grew steadily had fewer red flags at age two.
How this fits with other research
Li et al. (2023) used the same Italian cohort and found that gross motor plus receptive language delays, not expressive language alone, forecast later autism traits. The two papers overlap but spotlight different skills; together they tell us to watch multiple streams, not just words.
Laister et al. (2021) showed that preschoolers with richer gestures before ESDM treatment made bigger language gains after one year. Valentina et al. now push that signal even earlier—into babyhood—suggesting gesture count can guide referral before formal intervention starts.
Hsu et al. (2016) saw the same pattern in mixed-risk toddlers: fewer gestures and words at 15 months predicted later language impairment. The new study narrows the window to high-risk infants and links the pattern directly to ASD symptoms, not just general delay.
Why it matters
You can spot the highest-risk 12-month-olds by asking parents two quick questions: “Is your baby using new words?” and “Is your baby pointing or waving?” If both answers are “not yet,” flag for early evaluation and start parent coaching while you wait.
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02At a glance
03Original abstract
Delays in language are a hallmark feature of Autism Spectrum Disorder (ASD). However, little is known about the predictive role of language developmental trajectories on ASD. The present study aimed at identifying early different language developmental profiles of infants at high familial risk for ASD (HR-ASD) and testing their predictive role on ASD symptoms at 2 years. The role of gestures on socio-communicative skills has also been explored. Trajectories of expressive vocabulary were investigated in 137 HR-ASD infants at 12, 18, and, 24 months of age. Parents were requested to complete the Italian version of the MacArthur-Bates Communicative Development Inventory and ASD symptoms were measured by ADOS-2. Latent class growth analysis defined four trajectories: above average language development group (above-average LD, 18.2%), normal language development group (NLD, 38.7%), late-onset language development group (late-onset LD, 11.7%), and a group of children with stable language delay (SLD, 31.4%). Results showed that the SLD group obtained higher communicative difficulties and restricted/repetitive behavior compared to the other groups. Examining early increase of produced gestures in the different language classes, we found fewer produced gestures between 12 and 18 months in the SLD group compared to the late-onset LD group. The results identified clusters of HR infants who follow similar estimated trajectories based on individual differences in language development. These patterns of early language acquisition, together with produced gestures, may be predictive of later ASD symptoms and useful for planning prompt intervention. LAY SUMMARY: Language/gesture deficits are hallmark features of Autism Spectrum Disorder (ASD), but the predictive role of communicative trajectories on ASD remains unclear. In a longitudinal Italian sample of infants at high familial risk for ASD (HR-ASD), we tested if language trajectories and their link with gestures can predict ASD symptoms. We found four trajectories and HR infants with a stable language delay (SLD) trajectory showed more ASD symptoms later on. SLD infants produced fewer gestures compared to late-onset language development group that show more typical communicative skills.
Autism research : official journal of the International Society for Autism Research, 2021 · doi:10.1002/aur.2493