Parent-Reported Autism Spectrum Symptomatology in Children with Williams Syndrome

Background: Recent research has revealed a growing body of literature concerning the behavioral overlap between individuals with Williams syndrome (WS) and those with autism spectrum disorders (ASDs). WS is a genetic syndrome characterized by a typical physical appearance and cognitive profile, as well as an outgoing and friendly personality profile coupled with some degree of social reciprocity difficulties. Previous investigations have examined the socio-communicative behavioral profile of young children with WS using the Autism Diagnostic Observation Schedule (ADOS), as well as with parent questionnaires. However, patterns of behavior reported by parents of children with WS using a structured interview, the Autism Diagnostic Interview-Revised (ADI-R), have not been previously reported. These findings will be necessary in order to better understand the nature of socio-communicative difficulties present in WS.    

Objectives: The current study examined the behavioral profiles of 15 children with WS as reported by their parents using the ADI-R. Domain-level difficulties, as well as specific items commonly endorsed by parents, will be reported. In addition, relations between socio-communicative difficulties and developmental level will be examined.

Methods: The 15 children represented in the present study included eight boys and seven girls with WS between 2 and 6 years old. At least one parent of each child completed the ADI-R as part of a comprehensive evaluation that included a measure of early developmental level, the Mullen Scales of Early Learning (MSEL). This is not a random sample; many (though not all) of the participants were referred due to concerns about socio-communicative difficulties.  

Results: Of the fifteen children with WS assessed, seven (46.7%) met the autism cutoff for the reciprocal social interaction (RSI) domain. Twelve children (80%) met the autism cutoff in the communication domain and nine (60%) met the autism cutoff for restricted, repetitive, and stereotyped patterns of behavior (RRSB). Overall, seven children (46.7%) met the autism cutoff in all three domains. Patterns of individual item endorsement will also be analyzed. MSEL raw scores were not related to ADI domain scores. MSEL receptive and expressive language T-scores and overall developmental level were were negatively related to the RSI domain score.   

Conclusions: The results of the current study indicate that some children with WS do demonstrate socio-communicative difficulties that overlap with those typically seen in ASDs. In this sample of children with WS referred due to concerns about socio-communicative functioning, more than half met or exceeded the cutoff for ASD on the communication and repetitive behavior domains. The proportion demonstrating difficulties in the reciprocal social interaction domain was smaller but only marginally so. While not necessarily indicating that all of these children met criteria for a comorbid diagnosis on the autism spectrum, the results reveal that a number of children with WS, especially those with weaker receptive and expressive language, show sociocommunicative and repetitive behavior that overlaps with that seen for children with ASD. Implications of these findings will be discussed.