September 22, 2025, 9:15 am | Read time: 5 minutes
Rett syndrome is one of the rare genetic disorders and almost exclusively affects girls. In Germany, an estimated 5,000 people are affected, with about 50 new cases each year. A disturbing sign: After an uneventful first year of life, children suddenly lose skills they had already acquired.
What is Rett Syndrome?
Rett syndrome (RTT) is a neurological developmental disorder caused by mutations in the MECP2 gene on the X chromosome. This gene is crucial for the maturation and networking of nerve cells. When it does not function correctly, brain development stalls.
The disease was discovered in 1966 by Viennese pediatric neurologist Andreas Rett, who first described the typical “hand-washing” movements and became the namesake of the syndrome.1
Why Almost Only Girls Are Affected
- Boys have only one X chromosome. A mutation there usually leads to very severe courses, often ending fatally early.
- Girls have two X chromosomes. The healthy second chromosome partially compensates, allowing them to survive, albeit with significant limitations.
The frequency: about 1 in 10,000 girls. This makes Rett syndrome the second most common cause of intellectual disabilities in girls after Down syndrome.
Symptoms: When Development Suddenly Stops
In the first months of life, affected children develop seemingly without issue. However, between the 6th and 18th month, the picture changes:
- Developmental standstill: new skills do not emerge.
- Loss of already acquired skills: children speak less and forget movements or motor sequences.
- Stereotypical hand movements: wringing, tapping, or constant rubbing without apparent purpose.
- Walking problems: unsteady, wide-based gait or complete loss of walking ability.
- Loss of communication: children engage less with their environment, appear withdrawn, or retreat.
Other common accompanying disorders include:
- epileptic seizures (in about 80 percent of those affected),
- breathing disorders such as hyperventilation or breathing pauses,
- sleep problems, teeth grinding, digestive disorders,
- growth delays, scoliosis, and osteoporosis.
Parents often report a moment when they “no longer recognize their child”—a particularly distressing turning point.2
Four Stages of Progression
Doctors describe the progression of Rett syndrome in four typical phases. Not every child goes through them exactly the same, but the classification helps to better understand changes.
Stage 1: Early Onset (6–18 months)
Here, development subtly slows down. Babies seem less interested in their surroundings, eye contact decreases, and reaching for toys becomes less frequent. Many parents do not initially interpret this as a warning sign.
Stage 2: Rapid Regression (1–4 years)
In this phase, the symptoms become apparent. Children lose skills they previously mastered: words disappear, movements become uncertain. Stereotypical hand movements—wringing, rubbing, or constant hand-to-mouth actions—are typical. Breathing disorders and initial epileptic seizures may also occur.
Stage 3: Apparent Stabilization (2–10 years)
After the difficult regression phase, a sort of plateau follows. Children appear more alert, seek more contact, and show more interest in their environment. Therapies are particularly effective here. However, motor problems and epileptic seizures persist.
Stage 4: Late Motor Deterioration (from school age into adulthood)
In adolescence and adulthood, movement restrictions increase. Many affected individuals lose the ability to walk, develop scoliosis, or experience muscle stiffness. Nevertheless, they often remain attentive, respond to their surroundings, and communicate through looks or aids.3
Living with Rett Syndrome
There is currently no cure. Treatment focuses on alleviating symptoms and improving quality of life:
- Physical therapy: maintains mobility and prevents stiffness and misalignments.
- Occupational therapy: trains daily activities and motor skills.
- Speech therapy & assisted communication: such as boards, apps, or eye-tracking systems.
- Medications: relieve epilepsy, muscle cramps, or digestive issues.
- PEG tube: ensures nutrition when swallowing disorders make eating impossible.
- Music and art therapy: promote expression and participation.
Important: Even if verbal communication is limited, many girls have a very nuanced awareness and perceive their environment intensely.4
Families Between Strain and Hope
Rett syndrome turns the daily life of the entire family upside down. Care, therapies, doctor appointments—often around the clock. Many parents report physical and emotional exhaustion. At the same time, they describe the deep bond that develops in everyday life together.
Support is available through:
- Support groups
- Health insurance that covers therapies, care services, and aids.
- Care programs and retreats that relieve families.
- Psychological services to better cope with stress and strain.
Particularly helpful: a clear division of care, involving siblings and grandparents.
When a Tic Disorder Becomes Tourette Syndrome
Signs that already indicate Prader-Willi syndrome in babies
Research and Outlook
The life expectancy of girls with Rett syndrome is often over 40 years. Thanks to good care and support services, a stable quality of life is possible.
Worldwide research projects on gene therapies are ongoing. Initial studies raise hope that the genetic cause will be treatable in the future. However, it may still take years until clinical application.
Conclusion
Rett syndrome is rare but severe. It usually becomes noticeable after the first year of life when children lose already acquired skills. There is currently no cure, but therapies and support services significantly improve the quality of life. It is crucial that parents receive early support and do not face the diagnosis alone.5