If your child has been diagnosed with Rett syndrome, or you’ve newly met someone with this intellectual and developmental disability (IDD)—whether an immediate or distant family member, a friend or part of a friend’s family, a co-worker, a neighbor, or someone else—you certainly wouldn’t be alone in realizing you don’t know anything about it. So, here’s some introductory information and facts about Rett syndrome to help you better understand it.
Basic Facts About Rett Syndrome
- Rett syndrome almost exclusively occurs in females. It’s estimated that 1 in every 10,000 to 15,000 live female births of all ethnicities and races are affected.
- An Austrian physician named Andreas Rett first described this condition in 1966. However, it didn’t become generally recognized until 1983, following the publication of research by Dr. Bengt Hagberg of Sweden.
- The age of onset, rate of progression, and severity of symptoms varies from person to person.
- Children with Rett syndrome typically undergo normal growth and development at first (though there can be subtle signs from infancy), but then they experience four stages of impaired development and manifestation of symptoms.
- The first stage generally begins at 6 to 18 months of age, though the signs are often overlooked and the IDD isn’t diagnosed at this point. The earliest signs may include poor muscle tone, jerky limb movements, reducing eye contact, loss of interest in toys, delayed development of gross motor skills, and hand wringing. This stage usually lasts several months to a year, and sometimes longer.
- Stage two typically begins at age 1 to 4, and generally lasts for weeks to months. The child loses purposeful use of the hands, and begins prominent hand movements like wringing, tapping, clapping, clasping, and repeatedly moving them to the mouth. Also, loss of language usually occurs at this stage, as can diminishing social interaction, and breathing difficulties may manifest. Walking sometimes becomes unsteady, and head growth often lags.
- Stage three usually begins between ages 2 and 10, and it can last for years. The inability to perform motor functions and seizures are primary symptoms during this stage. At the same time, behavioral and social symptoms often improve during this stage.
- Stage four can last for years or even decades. It’s marked by decreasing mobility, muscle weakness, scoliosis, rigidity, spasticity, and abnormal posturing. Intellectual impairment generally does not get worse during this stage, and there may be improvements in symptoms like involuntary hand movements and lack of eye contact.
- Rett syndrome is almost always caused by a mutation in the methyl CpG binding protein 2 (MECP2). This gene is responsible for the production of a protein necessary for proper brain development and that plays a role in regulating the activity of other genes.
- Rarely, in what’s known as atypical or congenital Rett syndrome, the IDD is caused by mutations in the CDKL5 and FOXG1 genes.
- Although this is a genetic condition, it’s almost always randomly spontaneous—not inherited. However, sometimes other female family members of an affected individual are asymptomatic carriers who have the MECP2 gene mutation, but not the associated effects and symptoms.
- Because this condition occurs randomly, the chances of having a second daughter with Rett syndrome is less than 1%.
- The MECP2 gene mutation occurs on the X chromosome, and females have two in each cell, but only one is activated in each cell. The severity of Rett syndrome in any given person is determined by how many cells contain an activated affected X chromosome; the more cells in which the mutation is on the chromosome that’s turned off, the milder the condition.
- In the rare event that a boy has the MECP2 gene mutation, it’s a different situation because there’s only one X chromosome in each cell, so every cell is affected. A boy with Rett syndrome will generally be born with severe problems and die shortly thereafter.
- Rett syndrome is diagnosed clinically by observation of symptoms and ongoing evaluation of development. It’s confirmed by genetic testing that can identify the MECP2 gene mutation.
- There’s no cure for Rett syndrome, and treatment is focused on managing symptoms. Occupational and physical therapy can help with some symptoms, while medication is often needed for others like breathing irregularities, seizures, and motor problems. Equipment like braces or splints may be used, and a tailored nutritional program is sometimes indicated. Academic and social support services are also helpful for some affected people.
- Many people with Rett syndrome live well into middle age.