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Rett Syndrome

Rett syndrome is a neurological and developmental disorder that mostly occurs in females. Infants with Rett syndrome seem to grow and develop normally at first, but then stop developing and even lose skills and abilities. It is estimated to affect one in every 10,000 to 15,000 live female births and in all racial and ethnic groups worldwide.


Beginning between 3 months and 3 years of age, most children with Rett syndrome start to show some of the following symptoms:

  • Loss of purposeful hand movements, such as grasping with fingers, reaching for things, or touching things on purpose
  • Loss of speech
  • Balance and coordination problems, including losing the ability to walk in many cases
  • Stereotypic hand movements, such as hand wringing
  • Breathing problems, such as hyperventilation and breath holding, or apnea when awake
  • Anxiety and social-behavioral problems
  • Intellectual and developmental disabilities

Health care providers view the onset of Rett syndrome symptoms in four stages:

  • Early Onset Phase – Development stalls or stops.
  • Rapid Destructive Phase – The child loses skills (regresses) quickly. Purposeful hand movements and speech are usually the first skills lost.
  • Plateau Phase – Regression slows, and other problems may seem to lessen or improve. Most people with Rett syndrome spend most of their lives in stage 3.
  • Late Motor Deterioration Phase – Individuals may become stiff or lose muscle tone; some may become immobile.


Nearly all cases of Rett syndrome are caused by a mutation in the methyl CpG binding protein 2, or MECP2 (pronounced meck-pea-two) gene. Scientists identified the gene — which is believed to control the functions of many other genes — in 1999. The MECP2 gene contains instructions for the synthesis of a protein called methyl cytosine binding protein 2 (MeCP2), which is needed for brain development and acts as one of the many biochemical switches that can either increase gene expression tell other genes when to turn off and stop producing their own unique proteins. Because the MECP2 gene does not function properly in individuals with Rett syndrome, insufficient amounts or structurally abnormal forms of the protein are produced and can cause other genes to be abnormally expressed.

Not everyone who has an MECP2 mutation has Rett syndrome. Scientists have identified mutations in the CDKL5 and FOXG1 genes in individuals who have atypical or congenital Rett syndrome, but they are still learning how those mutations work. Scientists believe the remaining cases may be caused by partial gene deletions, mutations in other parts of the gene, or additional genes that have not yet been identified, and they continue to look for other causes.

Although Rett syndrome is a genetic disorder, less than 1 percent of recorded cases are inherited or passed from one generation to the next. Most cases are spontaneous, which means the mutation occurs randomly.


There is currently no cure for Rett syndrome. However, girls can be treated for some of the problems associated with the condition. These treatments generally aim to slow the loss of abilities, improve or preserve movement, and encourage communication and social contact.

People with Rett syndrome often benefit from a team approach to care, in which many kinds of health care providers play a role, along with family members. Members of this team may include:

  • Physical therapists, who can help patients improve or maintain mobility and balance and reduce misshapen back and limbs
  • Occupational therapists, who can help patients improve or maintain use of their hands and reduce stereotypic hand movements.
  • Speech-language therapists, who can help patients use non-verbal ways of communication and improve social interaction.

Other options, such as medication (such as for constipation or heart problems) or surgery (to correct spine curvature or correct heart defects) are also effective for treating some of the symptoms of Rett syndrome.



National Institute of Child Health and Human Development, USA.

National Institute of Neurological Disorders and Stroke, USA.