Language development in infants and toddlers with fragile X syndrome: change over time and the role of attention.

Fragile X syndrome (FXS) is associated with significant language and communication delays, as well as problems with attention. This study investigated early language abilities in infants and toddlers with FXS (n  =  13) and considered visual attention as a predictor of those skills. We found that language abilities increased over the study period of 9 to 24 months, with moderate correlations among language assessments. In comparison to typically developing infants (n  =  11), language skills were delayed beyond chronological age and developmental-level expectations. Aspects of early visual attention predicted later language ability. Atypical visual attention is an important aspect of the FXS phenotype with implications for early language development, particularly in the domain of vocabulary.