Rett syndrome (RTT) is a rare disorder characterized by normal early developmental growth followed by changes in typical patterns of mental and physical development. It is part of the Pervasive Developmental Disorders (PDD) classification and affects several races and ethnic groups around the world.

Although symptoms are similar to those of autism, RTT affects girls almost exclusively, whereas autism affects boys almost exclusively. Symptoms in RTT do not improve over time: they remain the same or get worse.

Initial signs and symptoms of RTT begin with a slowing of head growth and/or a loss of muscle tone. Around one to four years of age, a child with RTT may stop talking, lose social and language skills, and develop extreme social anxiety. Other symptoms may include difficulty walking and seizures. Apraxia—the inability to perform motor functions—is a severely disabling feature of RTT. Apraxia can affect every body movement, including eye gaze and speech (NINDS Fact Sheet, 2008).

There are four stages of RTT (NINDS, 2008). They are:

Stage 1 – Early Onset Stage
Age: 6 months to 1½ years
Duration: Months
Symptoms may include: less eye contact, loss of interest in toys, delays in sitting or crawling, hand wringing

Stage 2 – Rapid Destructive Stage
Age: 1 to 4 years
Duration: Weeks to Months
Symptoms may include: hand wringing/washing/clapping/tapping, hands moving to mouth repeatedly, breathing difficulties
Note: Some autistic-like behaviors may be present such as loss of social interaction and communication, general irritability, and sleep irregularities. You may also notice that the child has difficulty initiating motor movements or walking, and/or that head growth is slowing.

Stage 3 – Plateau Stage
Age: Preschool to Adulthood
Duration: Decades
Symptoms may include: apraxia, motor problems, and seizures; may show improvement in behavior including less irritability, crying, and autistic-like features; may show more interest in surroundings, increased alertness, attention span, and communication skills Note: Many girls remain in this stage for most of their lives.

Stage 4 – Late Motor Deterioration Stage
Age: 5 – 25+ years (when the ability to walk independently is lost or for those who don’t walk or move from stages 2 to 4)
Duration: Up to decades
Symptoms may include: reduced mobility – muscle weakness, rigidity (stiffness), spasticity (muscle tension), dystonia (increased muscle tone with abnormal posturing of extremity or trunk), and scoliosis (curvature of the spine); previous ability to walk is lost

Children with RTT are rarely able to live independently and need help for most activities of daily living (International Rett Syndrome Foundation, 2008). There are some treatments available that can help to improve the quality of life. They are: