The Development of Coordinated Communication in Infants at Heightened Risk for Autism Spectrum Disorder.

Researchers tracked how babies combine gestures with sounds. They watched high-risk infants who had older siblings with autism. The team filmed the babies at 8, 10, and 12 months. They counted how often each child paired a point or wave with a babble or word.

The study followed three groups: babies later diagnosed with ASD, babies with language delay, and typically developing babies. All infants came from families with an older child on the spectrum. This design let the team spot early warning signs before diagnosis.

Babies who later received an ASD diagnosis showed slower growth in gesture-plus-sound combos. Their rate of improvement lagged behind both language-delay and typical peers. The gap appeared between 8 and 12 months.

Language-delay babies looked similar to typical babies on this measure. Only the ASD group showed the slowed coordination pattern. The finding suggests this specific marker flags autism risk, not just slow language.

Rutherford et al. (2007) first spotted social lags in ASD siblings at 6-12 months. V et al. narrowed the signal to gesture-vocal timing, giving clinicians a clearer target to watch.

Garrido et al. (2017) pooled data showing language and motor delays in ASD siblings from 12-36 months. The current paper pins the first red flag two months earlier, at 8-10 months, and ties it to gesture-sound pairs rather than words alone.

Leezenbaum et al. (2019) found slower posture milestones in the same infant group. Together these studies map a cascade: motor delays appear first, then gesture-vocal coordination stalls, then language gaps widen.

You can add a 30-second check to your 12-month visit: count how often the baby pairs a point with a sound. Flat or falling numbers warrant referral, even if single milestones like waving are met. The tool costs nothing and picks up ASD risk before words emerge, giving families a head start on early intervention.