Rett Syndrome

Rett syndrome is a genetic disorder that causes a loss of spoken language and motor skills, as well as behavioral and neurological problems. Children with Rett syndrome may also have a variety of other medical problems, including intestinal, breathing, orthopedic, and heart complications.

Children with Rett syndrome often have normal development during the first six to 18 months of life. After this time, they have a period of regression (loss of skills) and they may lose speech and other developmental milestones. The symptoms can range from mild to severe. Almost all children with Rett syndrome are female.

Children with Rett syndrome have a wide variety of symptoms and a range of physical and mental impairments. Symptoms can include:

• Significantly impaired communication and cognitive (thinking) abilities
• Loss of the ability to speak
• Autistic-like symptoms, such as social isolation or withdrawal and reduced eye contact
• Compulsive hand movements, such as hand wringing, hand clasping, hand clapping, or repeatedly moving the hands toward the mouth
• Loss of motor skills, such as walking or crawling
• Breathing problems, including breath holding and hyperventilation
• Seizures
• Sleep problems
• Gastrointestinal problems, such as reflux and constipation
• Heart rhythm abnormalities, such as QT syndrome
• Scoliosis
• Kyphosis
• Microcephaly (small head size)
• Low muscle tone
• Irritability or agitation
• Teeth grinding (bruxism)
• Difficulty chewing and swallowing (dysphagia)
• Drooling

Rett syndrome results from disease-causing changes in the MECP2 gene located on the long arm of the X chromosome. This gene produces a protein called methyl-CpG binding protein 2, which is important for brain development and is believed to be involved in controlling the function of other genes. This protein is essential for the proper function of nerve cells and communication between neurons (brain cells). The specific job of the protein is not yet well understood. However, harmful changes in the gene lead to the symptoms of Rett syndrome.

Rett syndrome most often occurs as a result of a sporadic, or newly occurring, change in the MECP2 gene that was not inherited from the child’s parents.

Rett syndrome is diagnosed by a physical exam and detailed information about the child’s development and medical history. Key features of a Rett syndrome diagnosis include:

• Loss of normal hand use
• Loss of spoken language
• Trouble walking
• Abnormal hand movements such as hand wringing or clapping

Your child’s doctor may also order a genetic DNA blood test to support the diagnosis of Rett syndrome. This genetic test may detect a disease-causing change within the MECP2 gene. Most people with a clinical diagnosis of Rett syndrome (80 to 97 percent) have a change in this gene.

However, even if a MECP2 variation is found, the child may not be diagnosed with Rett syndrome if he or she doesn’t fit the clinical diagnostic criteria. For this reason, Rett syndrome is diagnosed by observing signs and symptoms during early development.

The guidelines for diagnosing Rett syndrome are divided into three types: essential, supportive, and exclusion.

Essential criteria

Essential criteria include symptoms that must be present for a child to be diagnosed with Rett syndrome. The essential criteria include:

• A period of normal development until between 6 to 18 months followed by a loss of skills, then recovery or stabilization of skills
• Partial or complete loss of purposeful hand skills
• Partial or complete loss of spoken language
• Dyspraxic gait (often an unsteady, wide-based, and stiff-legged gait)
• Repetitive hand movements (such as hand wringing or squeezing, clapping or tapping, or hand mouthing movements)

Supportive criteria

These include symptoms that are not necessary for a diagnosis of classic Rett syndrome but are often present in people with the disorder. A child who has supportive criteria, but no essential criteria does not have Rett syndrome. Supportive criteria include the following:

• Breathing irregularities while awake, such as apnea, hyperventilation, and air swallowing
• Teeth-grinding
• Abnormal sleep patterns
• Abnormal muscle tone (hypotonia, rigidity, or spasticity)
• Poor circulation in the hands and feet, with cold and bluish to red hands and feet
• Scoliosis or kyphosis (curvature of the spine)
• Delayed growth
• Small hands and feet
• Inappropriate laughing or screaming spells
• Reduced response to pain
• Intense eye communication or “eye pointing”

Exclusion criteria

Exclusion criteria allow doctors to rule out a diagnosis of Rett syndrome. A child with any of the following criteria does not have classic Rett syndrome:

• A neurometabolic disease or other inherited degenerative disorder
• A neurological disorder resulting from severe infection or head trauma
• Evidence of brain damage acquired after birth
• Grossly abnormal development in the first 6 months of life

While there is no currently targeted treatment or gene therapy for Rett syndrome, a care plan can be adapted to the needs of each child. With appropriate interventions, people with Rett syndrome can live well into middle age and beyond and can take part in social, educational, and recreational activities at home and in the community.

In many cases, the physical symptoms of Rett syndrome can be eased and managed with a robust regimen of therapies:

• Occupational therapy
• Speech therapy
• Physical therapy
• Augmentative communication

Some children may also benefit from medications for seizures, muscle stiffness, anxiety, or sleep difficulties.

The Boston Children’s Hospital Rett Syndrome Program is dedicated to helping children and adults who have Rett syndrome. We bring together a team of physicians and therapists from various fields who have expertise in Rett syndrome. Our team will work with your child and family to choose the best combination of therapies and medication to manage your child’s symptoms. We can also help your family access resources to help your child learn and thrive.