Rett syndrome is a developmental nervous system disorder primarily affecting girls. It is uncommon, but not rare, occurring in one out of every 10,000-23,000 female births.
Boys with the gene defect that causes this disorder are usually stillborn or die shortly after birth, though there have been a few cases where boys survive. Survival is more common in boys with Klinefelter syndrome or somatic mosaicism.
Rett syndrome can be classified into classic and atypical , depending on the symptoms.
Many people with Rett syndrome live into adulthood, but unfortunately most are severely handicapped. While many lack the ability to talk or walk, they usually have a full range of feelings and often communicate through their eyes. They usually require daily care from someone else throughout their lifetime.
The majority of cases of Rett syndrome are caused by nonhereditary, mutations in the Rett syndrome gene on one X chromosome. Females have two X chromosomes and males have one X and one Y chromosome. Males usually die from mutations in the Rett syndrome gene because they lack the second normal X chromosome which partially protects females.
The gene which is mutated in Rett syndrome affects methyl cytosine binding protein 2 (MECP2). When it is mutated, there is a deficiency of this important protein. The full significance of this is actively being evaluated.
Scientists have not yet discovered why the Rett syndrome gene is susceptible to mutation or what factors lead to this genetic damage. There do appear to be some hot spots on the gene which are more likely to develop mutations. Because Rett syndrome is usually nonhereditary, it does not commonly occur in multiple children within a family.
A risk factor is something that increases your chance of getting a disease or condition. There are no known risk factors for Rett syndrome except being female. The mutation that causes the syndrome appears to be sporadic, occurring only in a single X chromosome, and as a result, the chances of having a second child with Rett syndrome is very low, less than 1%.
A girl with Rett syndrome will start developing normally. She will smile, move, and pick items up with her fingers. But by 18 months of age, the developmental process seems to stop or reverse itself. The age of onset and the severity of symptoms can vary. There are four stages. Symptoms include:
Stage I: Early Onset Stage
Age: 6 to 18 months
Symptoms may include:
Less eye contact with parents
Less interest in toys and play
Slow head growth
Calm, quiet baby
Stage II: Rapid Destructive Stage
Age: 1 to 4 years
Duration: weeks to months
Symptoms may include:
Loss of muscle tone
Inability to purposely use hands
Loss of (previous) ability to talk
Repeatedly moving hands to mouth
Other hand movements, such as clapping, tapping, or random touching
Hand movements stop during sleep
Holding breath, gaps in breathing, taking rapid breaths
Irregular breathing stops during sleep
Laughing or screaming spells
Decreased social interactions
Trouble crawling or walking
Stage III: Plateau Stage
Age: preschool through school years
Symptoms may include:
Difficulty controlling movement
Less irritability and crying
Communication may improve
Stage IV: Late Motor Deterioration Stage
Age: when stage III ceases, can be anywhere from age 5 to 25
Duration: up to decades
Symptoms may include:
Decreased ability to walk
Muscle weakness or wasting
Stiffness of muscles
Scoliosis (curvature of the spine)
Breathing trouble and seizures often decrease with age
Puberty usually begins at the expected age
2008 Nucleus Medical Art, Inc.
The doctor will ask about your childs symptoms and medical history, and perform a physical and neurological exam. Evaluation can exclude other disorders such as autism . Genetic testing can often confirm the diagnosis.
Ninety-five percent of girls with Rett Syndrome, and 50% of those with atypical Rett Syndrome, have the MECP2 mutation. But not every individual with the MECP2 mutation will have Rett syndrome. Some females with MECP2 mutations may be normal or have only mild symptoms, but can then pass the gene to a daughter who can be more severely affected.
Although some of the motor functions of Rett syndrome, are similar to those of autism, most girls with Rett syndrome will prefer human contact to focusing on inanimate objects. Children with autism, more often boys, do not maintain person-to-person contact and, in contrast to girls with Rett syndrome, focus on things rather than people. These clinical differences may give the first clue in diagnosing Rett syndrome. Aside from genetic testing, the diagnosis is confirmed by comparing the physical and developmental findings with those typically found in Rett syndrome.
Tests may include:
Blood testto check for the responsible genetic mutation (MECP2)
Electroencephalogram (EEG)a test that records the electrical activity of the brain
Video-EEGa test that combines EEG with a video to see if some of the child's movements are caused by seizures
There is no cure for Rett syndrome. People with this disease need to be monitored for skeletal and heart problems that may develop later in the disease.
Treatment aims to control symptoms and includes:
Anticonvulsants to control seizure activity
Stool softeners or laxatives if constipated
Drugs to help with breathing
Drugs to ease agitation
Small, frequent meals
Tube-feeding, if the patient is unable to consume enough food
Fluids and high-fiber foods to help control constipation
Occupational therapy helps patients learn to perform daily activities, such as dressing and eating.
Physical therapy helps patients improve coordination and movement. It can sometimes prolong the ability to walk.
Therapists can recommend braces and splints.
Speech therapy aids in building communication skills.
Social workers help a family cope with caring for a child with Rett syndrome. Counselors help parents learn to manage behaviors.
Techniques for Limiting Problem Behaviors
Keeping a diary of the child's behaviors and activities helps determine the cause of agitation. The following may help to prevent or control behavior problems:
A quiet environment
There are no guidelines for the prevention of Rett syndrome because the cause is unknown and the mutation that causes it appears to be sporadic and unpredictable. If you have any questions about the risk of Rett syndrome in your family, you can talk to a genetic counselor.
International Rett Syndrome Association
National Institute of Child Health & Human Development
National Institute of Neurological Disorders and Stroke
Rett Syndrome Research Foundation
Ontario Rett Syndrome Association
Nelson Textbook of Pediatrics . 16th ed. WB Saunders Co.; 2000.
Psychiatry . WB Saunders Co.; 1997.
We'll keep the genes on for you. Neurology . 2001 Mar 13.
Last reviewed November 2007 by Rimas Lukas, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.