Rett syndrome is a unique developmental disorder that begins during infancy. Although it almost always affects girls, it may be seen — rarely — in boys. The syndrome is caused by mutations on the X chromosome on a gene called MECP2. On the other hand, individuals with the signs and symptoms of Rett Syndrome have been identified who do not have the genetic mutation.
Rett syndrome was identified by Dr. Andreas Rett, an Austrian doctor who first described it in an article in 1966. However, it was not until after a second article about the disorder was published in 1983 that the disorder was generally recognized.
The MECP2 gene makes a certain protein that is necessary for the development of the nervous system — especially the brain. Rett syndrome affects areas of brain function that are responsible for cognitive, movement, sensory, emotional, motor and autonomic function. These, in turn, can have an impact on learning, speech, sensory sensations, mood, breathing, cardiac function, as well as chewing, swallowing, and digestion.
A child who has Rett syndrome usually starts off in infancy with normal or near normal development. At about six to 18 months, there is a slowing down and even a regression of skills. The first indication that something is wrong may be loss of muscle tone (hypotonia). Diminished eye contact is another early symptom. The child begins to lose her ability to communicate. In addition to speech, she also loses intentional use of her hands and starts to make the same repetitive hand-washing motions. She also develops walking abnormalities. The normal rate of head growth is slowed, and she may suffer from seizures and irregular breathing patterns during waking hours. The child tends to be withdrawn during the early years and isolate herself, crying a lot and becoming irritable. Those symptoms generally lessen over time, and communication and eye contact improve.
Children with Rett syndrome can display a broad array of disabilities, ranging from mild to severe. The progression and severity of the disorder depends on the type, location, and severity of the genetic mutation and X-inactivation. So two girls who are the same age and have the same mutation can have very different disabilities.
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Want to learn more about Rett syndrome?
National Institute of Neurological Disorders and Stroke
International Rett Syndrome Foundation