Developmental profile of speech-language and communicative functions in an individual with the preserved speech variant of Rett syndrome

Objective: We assessed various aspects of speech-language and communicative functions of an individual with the preserved speech variant of Rett syndrome (RTT) to describe her developmental profile over a period of 11 years. Methods: For this study, we incorporated the following data resources and methods to assess speech-language and communicative functions during pre-, peri- and post-regressional development: retrospective video analyses, medical history data, parental checklists and diaries, standardized tests on vocabulary and grammar, spontaneous speech samples and picture stories to elicit narrative competences. Results: Despite achieving speech-language milestones, atypical behaviours were present at all times. We observed a unique developmental speech-language trajectory (including the RTT typical regression) affecting all linguistic and socio-communicative sub-domains in the receptive as well as the expressive modality. Conclusion: Future research should take into consideration a potentially considerable discordance between formal and functional language use by interpreting communicative acts on a more cautionary note.