Low speech rate but high gesture rate during conversational interaction in people with Cornelia de Lange syndrome.

Adams et al. (2021) watched short talks between people with Cornelia de Lange syndrome, people with Down syndrome, and typically developing peers. They counted spoken words and hand gestures during the same chats.

The team used matched groups to keep age and mental ability similar across the three sets. This let them see if CdLS produces extra gestures even when overall development is alike.

People with CdLS spoke fewer words per minute than both other groups. Yet they used about twice as many gestures for every 100 words spoken.

The high gesture rate shows the syndrome spares this expressive channel. Speech is slow, but hands carry extra meaning.

de Marchena et al. (2010) seems to disagree. They found adolescents with autism gesture as often as typical peers, but the timing of the gestures is off. The clash clears up when you look at the diagnosis: CdLS boosts gesture output to make up for tiny speech, while ASD keeps the same count but with poor rhythm.

Attwood et al. (1988) also saw ASD children start fewer expressive gestures than Down peers, matching the low-speech side seen here. E et al. extend that picture by showing CdLS flips the pattern—more gestures, not fewer.

de Korte et al. (2021) add that autistic adults move their hands differently even when gestures appear. Together the papers tell us to assess both how often and how smoothly clients use their hands.

If you serve someone with CdLS, do not rely only on spoken output. Count gestures during your preference assessment or mand trial; treat clear, intentional hand motions as valid responses. Build intervention that accepts gestures as mands or answers before pushing for more words. For other diagnoses like ASD, focus on timing and imitation drills rather than simply increasing gesture count. Tailor the channel you strengthen to the syndrome’s natural strength.