Impairments in Early Communication Skills in Toddlers with Autism and Williams Syndrome

Background: Williams syndrome (WS) is a genetic disorder which results in uneven cognitive profile and unlike autism syndrome (AS) is characterized by good social skills. We hypothesized that despite these syndrome-specific contrasting communication skills both genetic syndromes could be linked to the impairments in the ability to initiate triadic co-ordination (joint attention)

Objectives: We examined unique patterns of early social communication skills of young toddlers with AS and WS in comparison to typically developing children (TDC).

Methods: Early Social Communication Scale (ESCS, Peter Mundy, 2003) was administered to 8 children diagnosed with AS (chronological age (43,1±8)), 8 children with WS (43,6±15), and 18 TDC (22,7±7). Mental age was assessed with Bayley Scales(BSID II, 1993) and Psychological Educational Profile (Schopler et al, 1990). Three groups were matched for mental age. Repeated measures ANOVA was used for statistical analysis.

Results: The results showed that in average the early communication scores of autistic children were much lower than those of both TDC and WS children.  Despite superficially good social skills, toddlers with WS were only proficient in response to social interaction, whereas similarly to autistic children they were impaired in their ability to initiate communication with an adult. The unevenness of their communication profile was particularly striking in initiating joint attention skills.

Conclusions: Unlike autistic children, toddlers with WS displayed an uneven profile of their social communication. Despite superior responding to social interaction compared to AS, toddlers with WS were as delayed in the development of protodeclarative acts and triadic interaction as toddlers with autism. Atypical acquisition of early joint attention skills in WS may contribute to their subsequent abnormal cognitive and language development.