Study of Communication Deficits in the Siblings of Children with Autism Spectrum Disorders Using the Children's Communication Checklist-2: A Pilot Initiative from India

Background: Researchers have reported an increased risk for Siblings of children with Autism Spectrum Disorders (S-ASD) to have subtle characteristics of Autism Spectrum Disorder (ASD), known as the Broad Autism Phenotype (BAP). Though Pragmatic Language Deficit (PLD) is a hall mark feature of ASD, both PLD and structural language deficits have been reported in S-ASD. However studies are few and have not been convergent. Use of the Children’s Communication Checklist (CCC-2 Bishop, 2003) in the S-ASD has been reported in literature (Bishop, 2006; Taylor, 2013) to identify heritable ASD phenotype. The current pilot study attempts to explore communication deficits among S-ASD who belong to a different cultural background, thereby contributing to the existing literature. Such a study could allow one to gain further insight into the understanding of cross cultural phenotypic variations, if any.

Objectives: To compare the CCC-2 scores in siblings of children with ASD (S-ASD), Down’s Syndrome (S-DS) and siblings of typically developing (S-TD) children.

Methods: The study comprised a total of 63 participants divided into 3 groups; S-ASD (n=17), S-DS (n= 18) S-TD (n=28).  They were assessed on the CCC-2, a questionnaire that was filled by parents. Group differences were assessed on the two composite scores, the General Communication Composite (GCC) and the Social Interaction Deviance composite (SIDC) and also on a CCC-2 total score (total of all 10 subscales). Further each subscale was examined. Nonparametric tests with Bonferroni corrections were used to examine group differences.

Results: Kruskal-Wallis test showed significant differences between groups on the GCC (p=<0.001), SIDC (p=<0.05), CCC-2 total (p=<0.001) and 7 of the 10 subscales (p=<0.05). While there were no differences on the speech, syntax and semantics subscales- all three assessing structural language, there were differences on the sub-scales that assess i) pragmatic language (inappropriate initiation, stereotyped language, use of context, non-verbal communication) ii) behavioural domains relevant to ASD (social relations, interests) and iii) only on one subscale that assesses structural language (coherence). Thus the present study demonstrated that S-ASD have significant PLD over structural language deficits as measured by the CCC-2. In contrast to the previously reported studies (Bishop, 2003; Taylor 2013), the present study has demonstrated poor SIDC scores, an index sensitive to pragmatic impairment, in S-ASD. Mann-Whitney test indicated no group differences between the S-DS and S-TD indicating that differences in S-ASD cannot be attributed to presence of a sibling with disability alone.  

Conclusions: This study lends support to the presence of mild forms of PLD in S-ASD and suggestive of CCC-2 being a sensitive tool to pick up the same. It is also important to identify such PLDs in S-ASD early and initiate appropriate interventions. The present study warrants further exploration on a larger group supported by direct observations.