National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Rett syndrome


Other Names:
Autism, dementia, ataxia, and loss of purposeful hand use
Categories:
Rett syndrome is a progressive, neuro-developmental condition that primarily affects girls. Affected girls appear to have normal psychomotor development during the first 6 to 18 months of life, followed by a developmental "plateau," and then rapid regression in language and motor skills. Additional signs and symptoms may include repetitive, stereotypic hand movements; fits of screaming and inconsolable crying; autistic features; panic-like attacks; teeth grinding (bruxism); episodic apnea and/or hyperpnea; gait ataxia and apraxia; tremors; seizures; and slowed head growth. Some people have an atypical form of Rett syndrome that may be more mild or more severe. Classic Rett syndrome is most commonly caused by mutations in the MECP2 gene and is usually inherited in an X-linked dominant manner. The vast majority of cases are not inherited from a parent, but are due to a new mutation in the affected person. Treatment mainly focuses on the specific signs and symptoms of the condition.[1]
Last updated: 8/4/2014

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal pattern of respiration
Abnormal respiratory patterns
Unusual breathing patterns
[ more ] 		0002793
Absent speech
Absent speech development
Lack of language development
Lack of speech
No speech development
No speech or language development
Nonverbal
[ more ] 		0001344
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood
[ more ] 		0002376
Global developmental delay 0001263
High-pitched cry 0025430
Progressive microcephaly
Progressively abnormally small cranium
Progressively abnormally small skull
[ more ] 		0000253
Stereotypical hand wringing 0012171
30%-79% of people have these symptoms
Bradykinesia
Slow movements
Slowness of movements
[ more ] 		0002067
Difficulty walking
Difficulty in walking
0002355
Dystonia 0001332
EEG abnormality 0002353
Failure to thrive
Faltering weight
Weight faltering
[ more ] 		0001508
Limb apraxia 0030217
Seizure 0001250
Skeletal muscle atrophy
Muscle degeneration
Muscle wasting
[ more ] 		0003202
5%-29% of people have these symptoms
Abnormal autonomic nervous system physiology 0012332
Agitation 0000713
Cholecystitis
Gallbladder inflammation
0001082
Hyperammonemia
High blood ammonia levels
0001987
Inability to walk 0002540
Increased CSF lactate 0002490
Increased serum lactate 0002151
Increased serum leptin 0031793
Increased serum pyruvate 0003542
Infantile muscular hypotonia
Decreased muscle tone in infant
0008947
Scoliosis 0002650
Sleep disturbance
Difficulty sleeping
Trouble sleeping
[ more ] 		0002360
1%-4% of people have these symptoms
Congenital microcephaly 0011451
Percent of people who have these symptoms is not available through HPO
Abnormal T-wave 0005135
Abnormality of the dentition
Abnormal dentition
Abnormal teeth
Dental abnormality
[ more ] 		0000164
Apnea 0002104
Autistic behavior 0000729
Bruxism
Teeth grinding
0003763
Cachexia
Wasting syndrome
0004326
Cerebral cortical atrophy
Decrease in size of the outer layer of the brain due to loss of brain cells
0002120
Constipation 0002019
Dementia
Dementia, progressive
Progressive dementia
[ more ] 		0000726
Gait apraxia 0010521
Gait ataxia
Inability to coordinate movements when walking
0002066
Gastroesophageal reflux
Acid reflux
Acid reflux disease
Heartburn
[ more ] 		0002020
Intellectual disability, profound
IQ less than 20
0002187
Intermittent hyperventilation
Intermittent overbreathing
0004879
Kyphosis
Hunched back
Round back
[ more ] 		0002808
Motor deterioration
Progressive degeneration of movement
0002333
Postnatal microcephaly 0005484
Prolonged QTc interval 0005184
Short foot
Short feet
Small feet
[ more ] 		0001773
Short stature
Decreased body height
Small stature
[ more ] 		0004322
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
Truncal ataxia
Instability or lack of coordination of central trunk muscles
0002078
X-linked dominant inheritance 0001423
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Last updated: 7/1/2020
Rett syndrome is typically caused by changes (mutations) in the MECP2 gene. This gene provides instructions for making a protein (MeCP2) needed for the development of the nervous system and normal brain function. Mutations in the MECP2 gene that cause Rett syndrome can change the MeCP2 protein or result in the production of too little protein, which appears to disrupt the normal function of neurons and other cells in the brain.

Several conditions caused by changes in other genes (such as FOXG1 syndrome) have overlapping signs and/or symptoms of Rett syndrome. These conditions were once thought to be variant forms of Rett syndrome, but are now usually considered to be separate disorders.[2]
Last updated: 8/6/2014
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 sporadic, which means the mutation occurs randomly, and are not inherited. A few families have been described with more than one affected family member. These cases helped researchers determine that Rett syndrome has an X-linked dominant pattern of inheritance. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. The inheritance is dominant if one copy of the altered gene in each cell is sufficient to cause the condition.[3]
Last updated: 4/25/2016

The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.

Management Guidelines

  • Project OrphanAnesthesia is a project whose aim is to create peer-reviewed, readily accessible guidelines for patients with rare diseases and for the anesthesiologists caring for them. The project is a collaborative effort of the German Society of Anesthesiology and Intensive Care, Orphanet, the European Society of Pediatric Anesthesia, anesthetists and rare disease experts with the aim to contribute to patient safety.
Researchers don't know exactly how many people have Rett syndrome. Current estimates suggest that this condition occurs in about 1 in every 10,000 girls worldwide.[4] In the United States, the estimate is that Rett syndrome affects between 1 in 10,000 and 1 in 22,000 females.[5][6][7]
Last updated: 4/25/2016

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnosis includes autism and Angelman syndrome; cataract, retinopathy, or optic atrophy; history of perinatal or postnatal brain damage; confirmed inborn error of metabolism or neurodegenerative disorder; acquired neurological disorder due to severe head trauma or infection. Storage disorder is usually excluded by the presence of organomegaly.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Rett syndrome. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.
  • The Rett Syndrome, MECP2 Duplications, & Rett-related Disorders Consortium is an integrated group of academic medical centers, patient support organizations, and clinical research resources dedicated to conducting clinical research into three disorders of the nervous system: Rett syndrome (RTT), MECP2 duplication disorder and RTT-related disorders. Major goals of the Consortium are to identify and understand the core clinical features of each disorder; identify factors that can modify the severity of the disorders; and understand the relationship between patients’ symptoms and their brain imaging and electroencephalography alterations. Click on the name of the study for more information.
  • The Research Portfolio Online Reporting Tool (RePORT) provides access to reports, data, and analyses of research activities at the National Institutes of Health (NIH), including information on NIH expenditures and the results of NIH-supported research. Although these projects may not conduct studies on humans, you may want to contact the investigators to learn more. To search for studies, enter the disease name in the "Text Search" box. Then click "Submit Query".

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Social Networking Websites

  • RareConnect has an online community for patients and families with this condition so they can connect with others and share their experiences living with a rare disease. The project is a joint collaboration between EURORDIS (European Rare Disease Organisation) and NORD (National Organization for Rare Disorders).

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

Education Resources

  • The Genetics Education Materials for School Success (GEMSS) aims to assure that all children with genetic health conditions succeed in school-life. Their Web site offers general and condition-specific education resources to help teachers and parents better understand the needs of students who have genetic conditions.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Rett syndrome. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • How many Americans are diagnosed with Rett syndrome? See answer

  • I am a nurse, and I have a patient that presents with some of the classic signs of Rett syndrome. I want to locate a specialist in Rett syndrome genetics. Could your agency send me a list of practicing physicians and clinics with expertise in this area? See answer

  • Is it normal for girls with Rett syndrome to scream and cry? Can girls with Rett syndrome be potty trained? Also, is biting other children normal for girls with Rett syndrome? See answer

  • My friend's 3-year-old daughter was just diagnosed with Rett Syndrome. A boy sibling was born last week, and he does not have Rett syndrome. Where can we find more information? How do you become part of a clinical trial? See answer


  1. John Christodoulou and Gladys Ho. MECP2-Related Disorders. GeneReviews. http://www.ncbi.nlm.nih.gov/books/NBK1497/. Accessed 8/4/2014.
  2. Rett syndrome. Genetics Home Reference. December, 2013; http://ghr.nlm.nih.gov/condition/rett-syndrome. Accessed 8/6/2014.
  3. Rett syndrome. Genetics Home Reference (GHR). December 2013; https://ghr.nlm.nih.gov/condition/rett-syndrome.
  4. What is Rett Syndrome?. Rettsyndrome.org. http://www.rettsyndrome.org/about-rett-syndrome/what-is-syndrome. Accessed 4/25/2016.
  5. How many people are affected by or at risk of Rett syndrome?. Eunice Kennedy Shriver National Institute of Child Health and Human Development. January 14, 2014; https://www.nichd.nih.gov/health/topics/rett/conditioninfo/Pages/risk.aspx.
  6. Bernstein BE. Rett Syndrome. Medscape Reference. July 15, 2015; http://emedicine.medscape.com/article/916377-overview.
  7. Neul JL. Rett Syndrome. National Organization for Rare Disorders (NORD). 2015; http://rarediseases.org/rare-diseases/rett-syndrome/.