Early Vocal Development in Autism Spectrum Disorder, Rett Syndrome, and Fragile X Syndrome: Insights from Studies using Retrospective Video Analysis.

This article provides an overview of studies assessing the early vocalisations of children with autism spectrum disorder (ASD), Rett syndrome (RTT), and fragile X syndrome (FXS) using retrospective video analysis (RVA) during the first two years of life. Electronic databases were systematically searched and a total of 23 studies were selected. These studies were then categorised according to whether children were later diagnosed with ASD (13 studies), RTT (8 studies), or FXS (2 studies), and then described in terms of (a) participant characteristics, (b) control group characteristics, (c) video footage, (d) behaviours analysed, and (e) main findings.

Typical vs. atypical: Combining auditory Gestalt perception and acoustic analysis of early vocalisations in Rett syndrome.

Background: Early speech-language development of individuals with Rett syndrome (RTT) has been repeatedly characterised by a co-occurrence of apparently typical and atypical vocalisations.

Aims: To describe specific features of this intermittent character of typical versus atypical early RTT-associated vocalisations by combining auditory Gestalt perception and acoustic vocalisation analysis.

Methods And Procedures: We extracted N = 363 (pre-)linguistic vocalisations from home video recordings of an infant later diagnosed with RTT.

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.

Peculiarities in the gestural repertoire: an early marker for Rett syndrome?

We studied the gestures used by children with classic Rett syndrome (RTT) to provide evidence as to how this essential aspect of communicative functions develops. Seven participants with RTT were longitudinally observed between 9 and 18 months of life. The gestures used by these participants were transcribed and coded from a retrospective analysis of a video footage.

Early speech-language development in females with Rett syndrome: focusing on the preserved speech variant.

Aim: Our aim was to contribute new findings related to the pre-regressional verbal development of females with a variant of Rett syndrome (RTT) as the loss of spoken language is one of the key clinical features of RTT, and it would be of particular interest to study the early speech-language development of females who are considered to have preserved some speech-language abilities.

Method: We analysed 461 minutes of audio-video recordings containing play situations and the daily routines of six females (aged 7 to 24 months; mean birthweight 3057g, SD 195g) with the preserved speech variant (PSV) of RTT. All videos were recorded by parents and analysed retrospectively after the diagnosis PSV was made.