Speech and language skills of individuals with Prader-Willi syndrome

The speech and language of 55 individuals (27 males and 28 females) with Prader-Willi syndrome (PWS), aged from 6 months to 42 years, were examined through standardized testing and spontaneous speech sample analysis. While great variability was noted in speech and language abilities, most subjects presented with speech sound errors characterized by imprecise articulation (85%), and oral motor difficulties (91%). Hypernasality was noted in 62% and hyponasality in 14%. Other speech characteristics included a slow speaking rate, flat intonation patterns, abnormal pitch of the voice, and harsh/hoarse voice quality. Narrative retelling abilities were poor, with specific deficits in sequencing of story events. Individuals with PWS as a result of deletions of chromosome 15 did not differ significantly in speech and language from individuals with PWS as a result,of uniparental disomy.