Abstract
PURPOSE: Communication complexity and communicative function are important features of prelinguistic communication that are related to later language outcomes. However, little is known about how these early prelinguistic features present in young children with neurogenetic syndromes (NGS). This study aims to characterize prelinguistic complexity and function of children with three NGS: Angelman syndrome (AS), Down syndrome (DS) and fragile X syndrome (FXS). METHOD: Seventy-two infants aged 5-31 months (16 AS, 24 DS, 13 FXS, 19 low-risk control [LRC] infants) completed a parent-child interaction from which their prelinguistic communication was coded using the Communication Complexity Scale. Communication complexity (degree to which eye gaze, gestures, and vocalizations are integrated) and function (communication for the purposes of joint attention or behavior regulation) were compared among groups. RESULTS: The DS group used the most complex communication of the syndrome groups and in many ways demonstrated similar profiles to the LRC group. The AS and FXS groups exhibited the lowest overall communication complexity when covarying age, but their levels of complexity were similar to those of the LRC group when accounting for developmental level. The DS group showed a relative strength in communication for the purposes of behavior regulation. The FXS group demonstrated the lowest likelihood of using communication for the purposes of joint attention, while the AS group exhibited the lowest likelihood of communicating for the purposes of behavior regulation. CONCLUSIONS: Children with NGS exhibit nuanced differences in prelinguistic communication profiles that indicate unique strengths and areas of need. Additional work is needed to disentangle the effects of age and developmental level on prelinguistic communication profiles and to explore how these profiles are related to later language outcomes. Continuing to explore cross-group differences in prelinguistic communication may facilitate more targeted intervention and sensitive phenotyping among children with rare NGS.