Fact checking Bilingualism in Rett syndrome 

08/09/2025

A recent study has shown that in the very rare Preserved Speech Variant of Rett syndrome (around 3–5% of people with Rett syndrome), some individuals can develop bilingual skills. 

🔎 Why this matters: 

  • It highlights the potential of individuals with the Preserved Speech Variant of Rett syndrome. 
  • It challenges the historically low expectations of cognitive ability in Rett syndrome more broadly. 
  • It underscores that even when expressive speech is lost, many individuals retain strong receptive language—they understand far more than they can say. 
  • It underlines the importance of giving all people with Rett access to rich language environments and tailored communication support—  AAC and symbol-based systems or eye-gaze for those who are able to use it. 
  • It reinforces that there is no detriment to bilingual families (we know many) continuing to expose their family member with Rett to multiple languages as appropriate. 

Caveats: 

Preserved speech in Rett syndrome is extremely rare 
 

95-97%  of individuals with Rett syndrome do not have the Preserved Speech Variant.  

This means that some functional language is only retained in 3-5% of individuals with Rett. 

The vast majority of people with Rett syndrome lose almost all expressive speech and communicate instead through non-verbal methods, which may include expressions, gestures, AAC (augmentative and alternative communication), symbol based systems and eye gaze technology.  

Some people with Rett syndrome have very limited expressive communication and rely on families and carers to interpret their needs. 

The study cited is not representative 
Research showing bilingualism (both expressive and receptive communication) in Rett is based on very small numbers of individuals—this paper in particular is about a single person with Preserved Speech Variant. It is not generalisable to the wider Rett population. Presenting it as if bilingualism is broadly possible for “people with Rett syndrome” creates false expectations.  

Risk of misplaced pressure on families 
Suggesting that bilingualism is achievable for all people with Rett syndrome may cause guilt, confusion, or frustration for parents whose children cannot develop spoken language.  

Minimises the actual communication reality 
The vast majority of children and adults with Rett rely on non verbal communication eye gaze, switch systems, or picture-based AAC to communicate.  

At Reverse Rett, we believe advocacy for our community, including access to emerging treatments, vital services, benefits and legal protections depends on clear, accurate messaging.  

👉 In short: Yes, bilingualism (both expressive (speaking) and receptive (understanding) communication) has been observed in Rett syndrome-but only in the very rare Preserved Speech Variant. 

Children, young people and adults with Rett syndrome who do not have the PSV, may understand much more than they appear to, including additional languages which they are exposed to. This is an important way to acknowledge and include them in their own cultural heritage and identity. 

Link to the recent paper here 🔗 https://www.tandfonline.com/doi/full/10.1080/02699206.2025.2508260 

#RettSyndrome #Communication  #Neurodiversity