Rett Disorder

Rett disorder is an inherited brain condition that affects only girls. Before she reaches school age, a girl with the disorder stops developing normally and begins to lose such skills as walking and talking. Rett disorder is sometimes called Rett syndrome * . It is rare, occurring in only about 1 in 10,000 girls. Because of the rarity of the disorder and because it has not been recognized by the medical community for very long, most people have never heard of it.


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Genetic disorders

Rett syndrome

What Are the Signs and Symptoms of Rett Disorder?

A girl with Rett disorder develops and acts normally for some time after she is born. At first she seems to be perfectly healthy. She smiles, sits up, and may learn how to walk and talk. Then, at some time between about the ages of 5 months and 2½ years, she begins to lose the use of her hands to pick up and hold on to things. Instead, she begins to make certain movements with her hands and arms, which look as if she is repeatedly wringing or washing her hands. If she can walk, her gait becomes stiff and poorly coordinated. She also may lose the ability to say words and to respond to what other people say. She becomes less interested in playing with other children or in making friends. A typical sign of Rett disorder is that the child's head stops growing at the rate expected.

A girl who has Rett disorder frequently has other difficulties as well. She is often, but not always, severely mentally retarded. She may have seizures * and difficulty breathing at a normal rate, and she also may have scoliosis (sko-lee-O-sis), or spinal curvature.

* syndrome is a group or pattern of symptoms or signs that occur together.

* seizures (SEE-zhurs) are sudden attacks of involuntary (uncontrollable) body movements, changes in behavior, or loss of consciousness that result from bursts of abnormal electrical energy within the brain.

* genes are chemical substances in the body that help determine a person's characteristics, such as hair or eye color, and also are involved in determining certain health conditions. Genes are contained in the chromosomes found in the cells of the human body. They are inherited from parents.

* chromosomes (KRO-mo-somz) are threadlike chemical structures inside cells on which the genes are located. There are 46 (23 pairs) of chromosomes in normal human cells. Genes on the X and Y chromosomes (known as the sex chromosomes) help determine whether a person is male or female. Females have two X chromosomes; males have one X and one Y chromosome.

What Causes Rett Disorder?

Rett disorder is an example of a sex-linked genetic (je-NE-tik) disorder. disorder is inherited, which means that it is caused by one or more faulty genes * passed on from a parent. Girls with Rett disorder have one X-chromosome * that carries the faulty gene and another chromosome that carries a normal gene. Boys who inherit the disorder, on the other hand, have one X-chromosome that carries the faulty gene, but they do not have a matching X-chromosome with a normal gene. If a girl has a faulty gene for Rett disorder, the normal gene on the other X-chromosome can offset some of the effects of the faulty gene. The girl will live, but she will show signs of the disorder. It is believed that a boy fetus with the faulty gene will not survive to the time of birth, because he does not have a normal copy of the gene. This explains why only girls have Rett disorder. The faulty gene for Rett disorder was discovered in 1999, and scientists are still trying to learn more about it and what causes the disorder.

How Is Rett Syndrome Diagnosed and Treated?

Doctors can diagnose Rett disorder when they see the characteristic signs appear in a girl who had been developing normally. There is no cure for Rett disorder and development is often quite delayed. Treatments such as physical therapy and occupational therapy can lessen motor problems. A speech therapist may join the special education team to help the girl develop specialized ways of communicating, such as with the use of special electronic devices. Girls with the disorder will remain dependent upon others for their care throughout their lives. As they grow to adulthood, some girls become more interested in other people and are able to enjoy family and friends.

See also
Genetics and Behavior
Mental Retardation
Pervasive Developmental Disorders



Lewis, Jackie, and Debbie Wilson. Pathways to Learning in Rett Syndrome. London: David Fulton, 1998. This book offers special education advice for parents and teachers.


International Rett Syndrome Association, 9121 Piscataway Road, Clinton, MD 20735. This organization promotes the study and therapy of Rett disorder and offers information and other types of support to parents and families of children with the disorder.
Telephone 800-818-RETT

Rett Syndrome Center of the Baylor College of Medicine and Texas Children's Hospital, 6501 Fannin Street, Houston, TX 77030. This is one of the largest centers in the world engaged in the research of Rett disorder and its treatment.
Telephone 713-798-RETT .

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