Definition

Rett syndrome is a problem with the development of the nervous system. It is most common in girls. Boys with Rett syndrome are usually stillborn or die shortly after birth.

Many people with Rett syndrome live into adulthood. Most have severe disabilities, including an inability to talk or walk.

Causes

Rett syndrome is most often caused by nonhereditary mutations on a specific gene on 1 X chromosome.

Females have 2 X chromosomes. Males have 1 X and 1 Y chromosome. Males usually die from Rett syndrome because they lack a second normal X chromosome. The second normal X chromosome in girls may provide some protection.

In Rett syndrome, the mutated gene affects methyl cytosine binding protein 2 (MECP2). When it is mutated, there is a deficiency of this important protein. Not everyone with the MECP2 mutation will have Rett syndrome. Some females may be normal or have only mild symptoms.

It is not clear what causes the Rett gene to mutate. Rett syndrome is usually nonhereditary. This means it does not run in families.

Risk Factors

There are no known risk factors for Rett syndrome.

Symptoms

Children with Rett syndrome will start developing normally. They will smile, move, and pick items up with their fingers. But by 18 months of age, the developmental process seems to stop or reverse itself. The age of onset and the severity of symptoms are different from person to person. There are 4 stages. Symptoms for each stage include:

Stage IV: Late Motor Deterioration Stage

• Occurs at age when stage III ceases, can be anywhere from age 5-25
• Can last up to decades and include:
  • Decreased ability to walk
  • Muscle weakness or wasting
  • Stiffness of muscles
  • Spastic movements
  • Curvature of the spine
  • Breathing trouble and seizures that often decrease with age

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Diagnosis

You will be asked about your child’s symptoms and medical history. A physical and neurological exam will be done. Genetic testing can often confirm the diagnosis. Your doctor may also do tests to rule out other conditions, like autism.

Some symptoms of Rett syndrome are similar to those of autism. Children with autism, who are more often boys, do not maintain person-to-person contact. Most girls with Rett syndrome, though, prefer human contact to focusing on inanimate objects. These differences may give the first clue in diagnosing Rett syndrome.

Physical and developmental symptoms can often lead your doctor to a Rett syndrome diagnosis.

Your child's bodily fluids may be tested. This can be done with blood tests.

Your child's brain may be tested. This can be done with:

• Electroencephalogram (EEG)
• Video-EEG

Treatment

There is no cure for Rett syndrome. People with this condition need to be monitored for problems of the bones and heart.

Treatment aims to control symptoms and includes:

Prevention

There is no way to prevent Rett syndrome. If you have questions about the risk of Rett syndrome in your family, talk to a genetic counselor.