This feasibility study aims to estimate the parameters to inform a future randomised controlled trial to test whether an early social communication intervention is effective in improving language skills in young children with Down Syndrome.  In a two-arm randomised controlled trial (RCT), with 1:1 randomisation stratified by trial site, children were allocated to receive either the intervention plus standard NHS speech and language therapy, or standard NHS speech and language therapy only.   

In the intervention arm, parents/guardians received brief training videos on the parent-based intervention, a manual to follow with their child, a bag of toys and parent diaries. The intervention lasted 10 weeks. 

Twenty children with Down Syndrome, aged between 11 and 36 months were recruited into the trial and 19 were randomised. The dataset contains the baseline, post-treatment and 6 month follow-up data from 9 participants receiving the intervention (in addition to standard NHS speech and language therapy) and 10 control participants receiving standard NHS speech and language therapy only.