Rett syndrome (RTT) Symptoms and Diagnosis


Rett syndrome (RTT) Symptoms and Diagnosis


Some infants with RTT have a more severe case than others. The age at which a child begins to show symptoms of RTT also varies on a case-by-case basis.

There are four recognized stages of RTT. The sections below will look at each of these in more detail.

Stage 1: Early onset

This stage typically begins at 6–18 months old. During this early stage, the infant may show less eye contact and may also display reduced interest in their toys.

A child with RTT may also show delays in motor skill development, such as sitting or crawling. Other symptoms that can appear during this stage include hand-wringing and a decrease in head growth. However, the decrease in head growth is rarely enough to be noticeable this early.

Stage 1 often lasts for several months, but it can last for a year or more. The changes occur slowly and can be subtle, meaning that these early symptoms may go unnoticed.

Stage 2: Rapid destructive stage

The second stage of RTT often begins between the ages of 1 and 4 years old.

During this stage, the symptoms may develop rapidly or gradually. The infant will develop severe issues with communication, language, memory, movement, and other brain functions.

Some symptoms that may develop during stage 2 include:

  • loss of purposeful hand skills
  • loss of spoken language
  • characteristic hand movements, such as wringing, clapping, washing, or tapping
  • repeatedly moving the hands to the mouth
  • clasping the hands behind the back
  • breathing irregularities
  • loss of social interaction
  • loss of communication
  • unsteady walking
  • slowed head growth

Depending on the severity of RTT, not all of the above symptoms may be present during stage 2.

This second stage can last from 2 months to a few years.


Stage 3: Plateau

The third stage of RTT usually begins between the ages of 2 and 10 years old. The child’s behavior will often improve during this stage. This may lead to them being less irritable and crying less.

During stage 3, a child may also be more interested in their surroundings. They may be more alert, have a longer attention span, and show improved communication skills.

However, they may also develop motor problems and start to have seizures, which may become more common.

They may also develop irregular breathing patterns, such as shallow breathing followed by rapid breathing, deep breathing, or holding their breath.

This stage may last for many years. Females will often remain in this stage for most of their lives.

Stage 4: Motor deterioration

The final stage of RTT can last for years or even decades. The main symptoms of stage 4 RTT can include:

  • reduced mobility
  • losing the ability to walk
  • development of a curve of the spine, known as scoliosis
  • muscle weakness and abnormal stiffness

The person’s communication, language, and hand skills generally do not tend to get worse during stage 4.


A doctor will diagnose RTT by visually observing a child’s behavior and symptoms. This will often occur during the child’s early growth and development.

A doctor will then continue to carry out regular checks on the child’s physical and neurological status.

There is also a genetic test that can diagnose RTT. A doctor will carry out a blood test, and a laboratory will analyze the sample. The test looks for the mutated MECP2 gene and will come back either positive or negative.