Stages of Rett syndrome

Last updated Sept. 18, 2025, by Marisa Wexler, MS
Fact-checked by Jose Lopes, PhD

Rett syndrome is a genetic disorder that mainly affects girls and causes abnormalities in development, which are classically described as occurring over four stages.

While Rett syndrome progression typically happens in this way, it is important to note that these stages do not universally apply to every person with Rett. However, they are useful for understanding how Rett syndrome is likely to evolve over time, providing guidance for planning for future life stages.

How Rett syndrome typically progresses

Rett syndrome is defined by a specific pattern of development.

In the first few months of life, babies with Rett syndrome will generally show normal development, reaching milestones like making eye contact and rolling over. Then, typically between 6 and 18 months of age, social and motor development will stall. This is followed by a rapid period of regression, where children lose skills that they had previously acquired.

Once the regression ends, children will retain their skills and may even recover some abilities, though most will have long-term difficulties with movement and communication. As children with Rett enter adolescence and young adulthood, their cognitive and social capabilities will usually remain unchanged, but new movement problems may develop.

The four stages of Rett syndrome are used to describe symptoms progression:

Stage 1 is when the symptoms first appear and normal development stalls.
Stage 2 is marked by rapid regression and the loss of skills previously attained.
Stage 3 is when development plateaus, and where there may be some recovery.
Stage 4 when new motor symptoms develop.

Having the Rett syndrome stages explained is important for understanding how the disease may develop. But it must be stressed that these stages are just a general description of how the condition tends to manifest — there is no universal Rett syndrome timeline, and each individual’s experience with the disease will be unique. There is variability in Rett symptoms by stage, but overlap is possible, too. Also, these stages are mostly used to describe the classic form of Rett syndrome; developmental patterns are often different in atypical types of Rett.

Stage 1

The first stage of Rett syndrome is known as the early onset stage. It typically occurs between ages 6 months and 1.5 years and can last anywhere from a few months to a year.

Babies with Rett syndrome usually don’t display any obvious developmental abnormalities in the first months of life. The early onset Rett syndrome stage is where the first early signs of the disease start to become noticeable as development stalls. This may manifest with symptoms such as:

reduced interest in toys and interactions
delays reaching motor milestones like crawling or standing
reduced eye contact
low muscle tone
difficulty feeding
appearing very calm and placid

Stage 2

Stage 2 is known as the rapid destructive stage because it is marked by the loss of previously acquired skills in a short period of time. This typically manifests with symptoms such as:

loss of voluntary hand movement
abnormal repetitive hand movements, such as rubbing or squeezing the hands together
loss of speech
unusual behaviors such as unexplained bouts of crying or screaming
issues sleeping
hyperventilating and problems breathing
autistic characteristics, such as a lack of interest in social interactions

During this stage, children who are already saying words may stop doing so, and children who are babbling may babble less.

Stage 2 typically begins between ages 1 and 4. Developmental regression in Rett syndrome usually occurs quickly, often over the course of weeks to months.

Stage 3

The third stage of Rett syndrome is known as the plateau stage. This stage typically starts between ages 2 and 10, and it can last for many years — some people with Rett syndrome spend most of their lives in Stage 3.

In Stage 3, regression stops and skills stabilize. Sometimes, people in this stage of Rett can acquire new skills or re-acquire skills that they lost during the regression stage. Specific changes that may be seen in this stage include:

more interest in socialization
better ability to communicate
improved motor skills and better hand use
less crying and irritability
more alertness and a better attention span

Importantly, while people in this stage of Rett often experience some improvements, they will usually continue to require regular day-to-day support. Also, although behavior and communication may improve in this stage, movement problems at this stage are common. Seizures also may occur, and may be common.

Stage 4

The fourth stage of Rett syndrome is known as the late motor deterioration stage; it usually begins after age 10.

In this stage, communication, cognitive abilities, and hand skills usually remain unchanged. Seizures and abnormal Rett syndrome hand movements also tend to be less common than in earlier stages.

Stage 4 of Rett syndrome is typically marked by new motor disorders. Individuals who were able to walk may no longer be able to do so, and patients may also experience other issues, including:

involuntary muscle movements, known as dystonia
abnormally slowed movements, called bradykinesia
muscle weakness
joint contractures, or when joints become fixed in place
an abnormal sideways curvature of the spine, known as scoliosis

Support across stages

As individuals with Rett grow and move through the different stages of the disease, their support needs will change and evolve over time. After a Rett syndrome diagnosis, it’s important for families and clinicians to have in-depth discussions about treatment options so as to create a care plan that is suitable for the patient and situation. Rett patients typically need lifelong care, so families and clinicians should regularly check in to identify any needed changes in support.

Caring for someone with Rett will generally involve medications and nonpharmacological interventions like physical and occupational therapy to support functionality. The use of adaptive equipment can help in navigating day-to-day life more easily. Home modifications may be needed. Ensuring that caregivers have the support they need is also a key aspect of medical management for Rett syndrome.

Living with Rett syndrome presents unique challenges, but no one needs to face them alone. Organizations that offer support for families affected by Rett syndrome include:

Rett Syndrome News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.