Does the development of syntax comprehension show a premature asymptote among persons with Down syndrome? A cross-sectional analysis

peer reviewedUncertainty persists regarding the post-childhood trajectory of syntactic acquisition of persons with Down syndrome (DS). In some studies asymptote is reached in the early teens, whereas others find syntax continuing to develop at least into early adulthood. This study addressed the issue using a cross-sectional approach. Receptive syntax and receptive vocabulary were tested in 62 children, adolescents and young adults with DS matched on CA and cognitive level with 62 participants with intellectual disability of undifferentiated etiology. On both tests there were significant effects of CA and diagnosis, but the CA × diagnosis interactions were nonsignificant. It is concluded that comprehension of vocabulary and syntax does not asymptote prematurely among persons with DS