Distinct patterns of language impairment in Down's syndrome and Williams syndrome: The case of syntactic chains

This study presents experimental results on syntactic binding of reflexive and non-reflexive pronouns and on the comprehension of active and passive sentences in eight adolescents with Down's Syndrome (DS), and 10 with Williams Syndrome (WS). We propose a syntactic account of the difficulties of people with DS in these domains. We also compare our results on DS and WS with previous findings from studies using the same experimental tasks on adolescents with Specific Language Impairment (SLI). Distinct patterns of linguistic impairment were found for these developmental disorders indicating that at least in these syntactic domains different genetic etiologies are associated with different specifically linguistic patterns of impairment.