Classic Rett syndrome
Classic Rett syndrome is a progressive neurodevelopmental disorder primarily affecting girls. Is it characterized by:
- Normal psychomotor development during the first 6-18 months, followed by a short period of developmental stagnation, then a rapid regression of language and motor skills, followed by long term stability.
- Abnormal muscle tone, which may lead to muscle spasms and abnormal posture
- Foot and hand deformities
- Repetitive, stereotypic hand movements that replace purposeful hand use
- Fits of screaming and inconsolable crying
- Autistic features
- Panic-like attacks
- Teeth-grinding
- Irregular breathing
- Instability when walking or abnormal gait
- Tremors and seizures (90%)
- Generalized tonic clonic seizures and partial complex seizures are most common
- Acquired microcephaly (small head size)
- Scoliosis/kyphosis (80%)
- Diminished response to pain
- Small, cold hands and feet
- Bowel dysmotility, constipation
- Unusual eye movements
- Intense staring
- Blinking
- Closing one eye at a time
- Reduced bone mass (74%)
- Increased risk of fractures can occur
- Ambulatory individuals have better bone density than non-ambulatory individuals
- Increased risk of fractures can occur
- Growth failure and wasting that worsens with age (80-90%)
- May be caused in part by poor food intake
Atypical or variant Rett syndrome
- Intellectual disability with abnormal increase in muscle tone, muscle stiffness, or muscle tremors
- Age when symptoms first appear varies
- Mild learning disability (rare)
- Autism (rare)
Affected males
- In males, severe neonatal brain disease occurs, usually resulting in death before age 2