Children's Hospital Colorado

Rett Syndrome

What is Rett syndrome?

Classic or typical Rett syndrome is a neurological and developmental disorder that primarily affects girls. There are several variants, or types, of Rett syndrome. Prior to the availability of genetic testing, other distinct disorders were lumped together with Rett syndrome. Now, with genetic testing, we recognize each as a distinct disorder with different symptoms, different genetic findings and different treatments. We also now recognize that boys can be affected as well.

Infants with typical Rett syndrome appear to grow and develop normally at first, but then they stop developing and may lose skills and abilities. For example, children stop using sounds, words and vocabulary they have already learned. They often have difficulty walking properly and also lose some or all of their ability to use their hands. Children develop distinctive hand movements such as wringing, clapping or patting their hands. Some children may only have some of these symptoms.

What causes Rett syndrome?

Rett syndrome involves a change or misspelling in a gene called the MECP2 gene, which occurs on the X chromosome. Even though this is a genetic disorder, the change on the gene is usually new to the patient and not inherited from parents. In other words, a new spelling mistake happened around the time the egg and sperm came together. This is not caused by something the parents did or didn’t do.

In a very, very small percentage of patients (less than 1%), there may be a female relative who carries the gene but does not have symptoms of the disorder.

Who gets Rett syndrome?

Rett syndrome is a genetic disorder that usually affects girls. It affects about one in every 9,000 to 15,000 live female births in the United States. Males with Rett-related disorders are so rare that we do not know how often they happen.

Get to know our pediatric experts.

Craig Press, MD, PhD

Craig Press, MD, PhD

Child Neurology, Epilepsy

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Sharon Poisson, MD

Sharon Poisson, MD

Neurology, Vascular Neurology

Patient ratings and reviews are not available Why?

Susan Koh, MD

Susan Koh, MD

Child Neurology, Epilepsy

Tim Bernard, MD

Tim Bernard, MD

Child Neurology