Early Development in Infants at Risk of Childhood Apraxia of Speech: A Longitudinal Investigation

Abstract

This study examined early features of the heritable phenotype associated with childhood apraxia-of-speech (CAS). We compared speech and language development from 9 to 24 months of age in eight children at familial risk of CAS to that of eight infants with no such family history. At-risk infants scored lower on expressive language, speech development, and fine motor skills. Results support a broad, heritable verbal trait deficit for children at risk of CAS. Single case analyses showed poor prelinguistic speech development can dissociate from emerging receptive language and conceptualization skills, consistent with a deficit originating in speech motor control.

ACKNOWLEDGMENTS

We thank the speech-language pathologists and child-health nurses who assisted in recruiting families for this study, as well as the families involved in the study for their participation. We also thank two anonymous reviewers for their helpful feedback on an earlier version of this article.