A Case Study of Suspected Childhood Apraxia of Sign.

Purpose: We provide a case report of "Zoe," a 4-year-old deaf child from a deaf signing family, who presented with a possible case of Childhood Apraxia of Sign (CASign). Method: The description is based on reports from the child's speech-language pathologist, her Individualized Education Program report, and a clinician-created sign imitation task. Results: Zoe's sign articulation errors in American Sign Language differed from those reported for typically developing deaf children and were parallel to the types of errors observed for hearing children with childhood apraxia of speech. Specifically, Zoe produced inconsistent errors across signs, substituted more complex handshapes for simple handshapes, made errors on both unmarked (common) and marked (less common) forms, produced articulatory distortions (rather than substitutions), and exhibited "groping" behaviors (a sequence of attempts to move her hands into the correct position). In addition, Zoe sometimes self-corrected her errors by manipulating her own hands, for example, using her left hand to move the thumb of her right hand into the correct position. Conclusion: Zoe's pattern of sign errors is consistent with an underlying deficit in motor planning and/or programming and may constitute the first reported case of CASign.