Rett syndrome is a rare genetic condition. It occurs from genetic variations on the X chromosome that happen in the early stages of fetal development.

Rett syndrome is a genetic condition that primarily affects females. It rarely occurs in males.

Dr. Andreas Rett first described the condition in 1966. Rett syndrome involves a wide range of physical, cognitive, and social symptoms.

Genetic variations on the X chromosome cause Rett syndrome, which is why it is more common in females. Females usually have two X chromosomes.

Read on to learn more about the genetic changes that can lead to the development of Rett syndrome.

A person preparing for an ultrasound-1.Share on Pinterest
Ljuba Photo/Getty Images

Most cases of Rett syndrome occur due to a variation in the methyl CpG binding protein 2, or MECP2 gene. This gene contains the instructions for producing a protein necessary for brain development. It has the role of activating or deactivating gene functions during fetal development.

Alterations in the MECP2 gene cause it to either produce insufficient amounts of the protein or a protein that the body cannot use. Due to these changes, the protein cannot help the brain develop normally, resulting in Rett syndrome.

Almost all people living with Rett syndrome have no family history of the condition. Instead, the gene alteration occurs spontaneously.

The MECP2 gene is present on the X chromosome, which is one of the sex chromosomes. This is why the condition occurs more frequently in females.

Worldwide, Rett syndrome occurs in roughly 1 of every 10,000 female births, according to the International Rett Syndrome Foundation.

Symptoms of Rett syndrome usually become noticeable at 6–18 months of age. A caregiver may notice signs as the child begins to miss developmental milestones or loses abilities they had gained.

Symptoms of Rett syndrome may include:

  • involuntary and repetitive hand movements, such as handwashing
  • loss of mobility or function in the hands
  • loss of speech
  • mobility or walking problems
  • hypotonia, which is loss of muscle tone
  • seizures
  • scoliosis
  • breathing problems
  • difficulty sleeping
  • slowed growth rate of the head, feet, and hands

To diagnose Rett syndrome, a doctor first observes the signs and symptoms during the child’s growth and development. After, they conduct evaluations of the child’s physical and neurological status.

A doctor may also recommend a genetic test. A genetic test can confirm the diagnosis by identifying the specific MECP2 gene variation.

To do this test, a medical professional takes a blood sample and sends it to a laboratory. A professional then analyzes the sample to find any gene alterations.

At present, there is no cure for Rett syndrome. Instead, treatment involves a multidisciplinary care team that works to improve the person’s quality of life.

A person’s care team may include:

In 2023, the Food and Drug Administration approved trofinetide (Daybue) for treating Rett syndrome. This drug works by reducing brain swelling, increasing protective proteins in the brain, and stopping some cells from becoming too active.

Rett syndrome shares similarities with other neurodevelopmental disorders. These include:

CDKL5 deficiency disorder

The cyclin-dependent kinase-like 5 (CDKL5) gene also provides instructions for an important protein for typical brain development and function.

CDKL5 deficiency disorder occurs when there is a shortage of this protein, or the protein does not function correctly.

Previously, doctors would classify this condition as a variant of Rett syndrome. However, it is now an independent condition.

FOXG1 syndrome

The forkhead box G1 (FOXG1) gene is also responsible for producing an important protein for early brain development. A deficiency of the protein or impairment of its function can disrupt brain development and lead to FOXG1 syndrome.

Doctors referred to FOXG1 syndrome as a variant of Rett syndrome but now consider it distinct.

Angelman syndrome

Angelman syndrome is another genetic condition that can cause developmental delays. It occurs from a gene variation that prevents the UBE3A gene from functioning normally.

People typically inherit two copies of this gene from their parents. However, problems with the maternal copy of this gene may cause it to not be active in some parts of the brain, resulting in symptoms of Angelman syndrome.

Autism spectrum disorder (ASD)

ASD is an umbrella term that includes a range of neurodevelopment features. Both ASD and Rett syndrome involve social and communication challenges, but Rett syndrome typically involves more severe cognitive and physical impairments.

Cerebral palsy

Cerebral palsy describes a set of neurological conditions that affect movement. Because both conditions involve motor impairments, a misdiagnosis is possible. However, cerebral palsy is typically nonprogressive, while Rett syndrome involves regression.

Signs of Rett syndrome can be subtle in the early stages.

The problems that relate to Rett syndrome occur when the MECP2 gene is unable to perform its function, which is often when a child should be reaching important milestones.

Caregivers can watch for any of the following signs in children:

  • developmental regression
  • loss of purposeful hand skills
  • withdrawal from social interactions
  • slowed growth

If a caregiver notices any of the above signs or has any concerns, they should consult a healthcare professional. Early diagnosis and intervention are crucial for managing Rett syndrome effectively and optimizing the child’s development.

Rett syndrome is a genetic neurodevelopmental condition. It typically occurs due to alterations in the MECP2 gene. This gene is responsible for producing a protein essential for growth and development. Without this protein, the brain is unable to develop normally.