Language and motor skills in siblings of children with autism spectrum disorder: A meta-analytic review.
Baby siblings of autistic children show clear language delays and mild motor lags by one year—screen early and refer fast.
01Research in Context
What this study did
Garrido et al. (2017) pooled data from many small studies. They asked one question: Do baby brothers and sisters of autistic children talk or move on time?
They looked only at kids who did not yet have an autism diagnosis. Ages ranged from 12 to 36 months.
The team compared these “ASD-sibs” to siblings of typically developing kids. They measured both language and motor skills.
What they found
Language delays showed up loud and clear. Receptive and expressive gaps were medium-sized and stayed steady across the second and third years.
Motor delays were smaller but real. Fine and gross skills both lagged, though the gap was mild.
In short, being an ASD-sib raises the odds of slower talking and slightly slower moving.
How this fits with other research
Older single studies saw the same language lag. Yirmiya et al. (2007) and Rutherford et al. (2007) both reported receptive and expressive delays in toddlers. The meta-analysis confirms their early hints with stronger numbers.
Two papers seem to disagree. Levy et al. (2011) and Chuthapisith et al. (2007) found no language gap once they controlled for IQ or looked only at non-verbal-ASD families. The difference is sample choice: they studied older siblings or special proband groups, while Dunia et al. averaged across all infant siblings.
Newer work extends the motor piece. Sosnowski et al. (2022) tracked trajectories and showed that atypical motor paths forecast later autism symptoms. Redquest et al. (2021) added that fine motor stalls as early as 9 months predict higher autism likelihood. These findings line up with the small motor deficits Dunia et al. reported.
Why it matters
Start watching language and motor milestones at the 12-month visit for any baby with an autistic sibling. Use a quick parent checklist or pull out the Mullen scales. If scores fall low, refer to early intervention right then—don’t wait and see. Targeting both talking and fine-motor play in one plan may give the biggest developmental boost.
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02At a glance
03Original abstract
UNLABELLED: Children with autism spectrum disorder (ASD) show significant linguistic and motor impairments compared to children with typical development (TD). Findings from studies of siblings of children with ASD show similarities to conclusions from studies of children with ASD. The current meta-analysis reviewed studies reporting linguistic and/or motor skills in siblings of children with ASD compared to siblings of children with TD. Thirty-four studies published between 1994 and 2016 met all inclusion criteria. We compared three different age groups (12 months or younger, 13 to 24 months, and 25 to 36 months). At 12 months, compared to siblings of children with TD, siblings of children with ASD had worse receptive language (d = -.43, 95% CI [-.53, -.33]) and expressive language skills (d = -.40, 95% CI [-.57, -.23]), and these effects were sustained at 24 and 36 months. Similar, albeit smaller differences in fine motor skills were detected at 12 months (d = -.22, 95% CI [-.39, -.04]), and these differences were larger at 36 months (d = -.36, 95% CI [-.54, -.17]). There were differences in gross motor skills at 12 months (d = -.22, 95% CI [-.40, -.04]), but only a few studies were available at later ages. Compared to siblings of children with TD, infants who have siblings with ASD have worse linguistic and motor skills. These differences are detectable as early as when infants are 12 months old and seem to be sustained until they are 3 years old. Differences in language skills are larger than those in motor skills, especially during the first year. Autism Res 2017, 10: 1737-1750. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We reviewed studies reporting linguistic and/or motor skills in siblings of children with autism spectrum disorder (ASD) compared to those in siblings of children with typical development. The results showed that as a group, those infants who have siblings with ASD have less advanced linguistic and motor skills. These differences are detectable when infants are 12 months old and seem to be sustained until they are 3 years old. Differences in language skills are larger than those in motor skills.
Autism research : official journal of the International Society for Autism Research, 2017 · doi:10.1002/aur.1829