In general, these findings were consistent with previous work [5,27] showing increased levels of FMRP to be associated with development and language-related functions; however, whereas we did not show a direct association between FMRP and speech and language functions, we did uncover three-way interactions for each of the outcomes suggesting the importance of FMRP in moderating the relationship between Autism status [19], developmental level, and speech and vocabulary development in boys with FXS. Here, FMR1 is linked to autism.