Rett syndrome

Rett syndrome is a rare genetic, neurodevelopmental disorder. It predominantly affects females, with males affected much more rarely, and usually less severely. 

Although Rett syndrome is present at birth, it typically goes undetected until around the child’s first birthday, when it is noted that they begin to lose acquired skills. 

How many people are affected?

Rett syndrome is estimated to affect 1 in 10,000-12,000 female babies, across all racial and ethnic groups worldwide.

Prenatal testing is available for families with an affected daughter, however since the disorder occurs spontaneously in most  affected individuals, the risk of a family having a second child with the disorder is less than 1 per cent.  

How it affects people

Those affected by Rett syndrome can have multiple physical and learning disabilities, and are reliant on others for support throughout their lives. The disorder can in most cases be confirmed through genetic tests, and also by clinical diagnosis looking for signs and behaviours. Typical signs of Rett syndrome are:

  • a slowing in developmental progression from the age of one
  • regression in development when skills in speech and hand movement are reduced
  • development of repetitive hand movements such as patting, clapping and tapping
  • the appearance of stiff or clumsy posture
  • a normal head circumference at birth, with a slowing of head growth up to the age of four years.

Other signs often seen include:

  • areathing irregularities
  • EEG (electroencephalogram) abnormalities
  • epilepsy
  • muscles becoming increasingly rigid with age
  • unsteady wide-based gait
  • development of scoliosis
  • teeth grinding.

The four stages

The signs and symptoms of Rett Syndrome are generally seen to appear in four stages:

Stage one

Early signs and slow development between the ages of 6 and 18 months. This stage can often be overlooked due to its vague and subtle symptoms, lasting for between a couple of months and one year.

Stage two

Developmental regression starts to occur between the ages of 1 and 4 years, with this stage lasting for a number of weeks or months.

Stage three

The plateau stage is seen between the ages of 2 and 10 and can last for a number of years.

Stage four

Deterioration in movement and motor skills presents which can last for years or decades.


There is no cure for Rett syndrome, but people affected, along with their families, can be supported to manage the symptoms through a multidisciplinary approach.

Medication can be used in some cases to help with any breathing or motor difficulties, occupational therapy can be used to enable children to develop skills needed for self-directed activities, and physiotherapy can be used to aid and prolong mobility.

Read the National Institute of Neurological Disorders and Stroke Rett Syndrome Fact Sheet for more information.