Variations of stereotypies in individuals with Rett syndrome: A nationwide cross-sectional study in Taiwan.
Atypical RTT brings a wider menu of hand stereotypies, and three common ones fade after ten in classic RTT.
01Research in Context
What this study did
Lee’s team mailed surveys to every family in Taiwan listed in the Rett syndrome registry. They asked parents to check off every hand movement their daughter showed in the past month. Fifty-eight girls and women with classic or atypical RTT were included.
The survey listed 14 common hand stereotypies such as flapping, wringing, clapping, and single-hand mouthing. The team then counted how many different movements each person showed and looked for age trends.
What they found
Girls with atypical RTT displayed more kinds of stereotypies than girls with classic RTT. The average atypical case showed eight different hand movements; the average classic case showed five.
In classic RTT, three movements—flapping, clapping, and single-hand mouthing—dropped off sharply after age ten. Wringing stayed high at every age. Atypical RTT showed no clear age drop-off.
How this fits with other research
Scahill et al. (2015) screened 24 tools for measuring repetitive behaviors and picked only five as trial-ready. Lee’s simple parent checklist lines up with two of those picks—ADI-R and RBS-R—showing that low-cost surveys still give useful topography data.
Jabbar et al. (2026) used AI to spot hand-flapping in home videos of kids with ASD. Their algorithm found flapping in 93 % of clips. Lee’s survey data now tell us that flapping is also common in RTT but fades after ten, a nuance the AI study could not detect.
Gillberg et al. (1983) warned that early stereotypy treatment studies were weak. Lee’s 2017 map gives today’s researchers a clearer baseline so future RTT interventions can be judged against solid descriptive norms.
Why it matters
If you assess a girl with RTT, expect more varied hand movements if her mutation profile is atypical. Track flapping, clapping, and mouthing before age ten; these may decline and should not be the only target behaviors in older clients. Use the parent checklist or RBS-R to capture the full range, then pair with AI video tools for objective counts. This combo gives you both the ‘what’ and the ‘how much’ needed for strong treatment plans.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Add ‘stereotypy variety’ as a line item on your intake form and re-score it every six months.
02At a glance
03Original abstract
Individuals with Rett syndrome (RTT) can have variable manifestations of stereotypies. In this nation-wide cross-sectional study, we recruited all individuals with RTT in Taiwan diagnosed as RTT by neurologists based on genetic findings and diagnostic criteria. The data were collected using questionnaire. A total 43 cases of typical RTT and 15 cases of atypical RTT, aged from 2.1 to 40.1 years, were enrolled. They included 3 (5.2%) in stage II, 42 (72.4%) in stage III, and 13 (22.4%) in stage IV. All individuals presented with at least one stereotypy. Individuals with atypical RTT had more varied stereotypies (mean: 14 ± 6) compared to those with typical RTT (mean: 9 ± 5) (P = 0.003). Flapping (73.3%) and wringing (58.1%) were the most common hand stereotypies in atypical and typical RTT, respectively. Compared with typical RTT, hair pulling, bruxism, retropulsion, and protrusion of lips were more common in atypical RTT (P = 0.003, P = 0.006, P = 0.003 and <0.001, respectively). The number of stereotypies did not differ among different stages, clinical severities, and hand functions. Although there were no age-related changes in stereotypies in atypical RTT, flapping (P = 0.012), clapping (P = 0.044), and mouthing with single hand (P = 0.009) were significantly more prevalent in individuals aged <10 years with typical RTT, and they decreased after 10 years. In conclusion, our study showed that the stereotypical movements varied in typical and atypical RTT, implying the heterogeneous nature of the disease and the pathogenic mechanisms of RTT with atypical features. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1204-1214. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
Autism research : official journal of the International Society for Autism Research, 2017 · doi:10.1002/aur.1774