Preliminary examination of the function served by challenging behaviours associated with Fragile X and Smith Magenis syndrome

Aims: Certain topographies of challenging behaviour, such as self-injury, constitute part of the behavioural phenotype for fragile X syndrome (FXS) and Smith-Magenis syndrome (SMS). Only a small handful of studies have gone beyond behavioural form to address the function served by challenging behaviours associated with such syndromes.

Method: The current study adopted indirect functional assessment methods, using the Questions About Behavioral Function scale, to examine the function served by challenging behaviours displayed by children with FXS and SMS in comparison to a heterogeneous sample of children with intellectual and developmental

disabilities. There were approximately 30 participants in each group.

Results: Between-group analysis revealed differences between each group in the total scores for certain subscales. For example, in comparison to other groups, children with FXS were significantly less likely to display challenging behaviours maintained by attention. Within-group analysis also supported these findings.

Conclusions: Results are discussed in relation to the concept of gene-environment interaction (GxE) and the implications such relations may hold both for our understanding of the early development of challenging behaviour and in directing efforts at prevention and early intervention.