Assessment & Research

The prevalence and phenomenology of repetitive behavior in genetic syndromes.

Moss et al. (2009) · Journal of autism and developmental disorders 2009
★ The Verdict

Each genetic syndrome carries its own repetitive-behavior fingerprint—Fragile X high, Angelman low, others in between.

✓ Read this if BCBAs assessing repetitive behavior in genetic syndromes
✗ Skip if Clinicians only tracking broad autism traits

01Research in Context

01

What this study did

The team gave the Repetitive Behavior Questionnaire to people with seven genetic syndromes.

They wanted to see if each syndrome has its own pattern of repetitive acts.

02

What they found

Fragile X showed lots of repetitive behavior. Angelman showed little.

Prader-Willi, Cri-du-Chat, and Smith-Magenis each had their own unique mix.

03

How this fits with other research

Plant et al. (2007) first used the RBQ in fragile X and found boys repeat more phrases than girls.

NMStagnone et al. (2025) later looked at thirty rare gene types and saw mostly similar autism traits, not unique profiles. This seems like a clash, but the 2025 study used broader autism scales, not the fine-grained RBQ items.

Yip et al. (2009) showed that in severe ID, many repetitive acts serve social functions. Joanna et al. now add that the form of these acts changes by syndrome.

04

Why it matters

Pick the right tool. If you want syndrome-level detail, use the RBQ. If you want broad autism risk, use the 2025 battery. Either way, treat the behavior you see as a signal, not just noise.

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Pull the RBQ for your next fragile X case and compare scores to the syndrome profile.

02At a glance

Intervention
not applicable
Design
survey
Sample size
797
Population
intellectual disability, other
Finding
not reported

03Original abstract

We investigated the prevalence and phenomenology of repetitive behavior in genetic syndromes to detail profiles of behavior. The Repetitive Behaviour Questionnaire (RBQ) provides fine-grained identification of repetitive behaviors. The RBQ was employed to examine repetitive behavior in Angelman (N = 104), Cornelia de Lange (N = 101), Cri-du-Chat (N = 58), Fragile X (N = 191), Prader-Willi (N = 189), Lowe (N = 56) and Smith-Magenis (N = 42) syndromes and individuals with intellectual disability of heterogeneous aetiology (N = 56). Repetitive behavior was variable across syndromes. Fragile X syndrome scored highly on all subscales. Angelman syndrome demonstrated a significantly lowered probability for most behaviors. Prader-Willi, Cri-du-Chat and Smith-Magenis syndrome evidenced unique profiles of repetitive behavior. There is extreme heterogeneity of repetitive behavior across genetic syndromes, highlighting syndrome specific profiles.

Journal of autism and developmental disorders, 2009 · doi:10.1007/s10803-008-0655-6