The Rett-syndrome is a rare genetic postnatal neurological disorder of the grey matter of the brain that almost exclusively affects females but has also been found in male patients. The clinical features include small hands and feet and a deceleration of the rate of head growth (including microcephaly in some). Repetitive stereotyped hand movements, such as wringing and / or repeatedly putting hands into the mouth, are also noted. People with Rett syndrome are prone to gastrointestinal disorders and up to 80% have seizures. They typically have no verbal skills, and about 50% of individuals affected do not walk. Scoliosis, growth failure, and constipation are very common and can be problematic.
The initial development is normal. Onset occurs between 6 and 18 months of age. During this time there are subtle developmental deviations and early indicators of Rett syndrome. A period of developmental stagnation is followed by developmental regression where language and motor milestones regress, purposeful hand use is lost, and acquired deceleration in the rate of head growth (resulting in microcephaly in some) is seen. Hand stereotypes are typical, and breathing irregularities such as hyperventilation, breath holding, or sighing are seen in many. Early on, autistic-like behaviour may be seen. The infant with Rett syndrome often avoids detection until 6–18 months, owing to a relatively normal appearance and some developmental progress. However, closer scrutiny reveals disturbance of the normal spontaneous limb and body movements that are thought to be regulated in the brainstem. The brief period of developmental progress is followed by stagnation and regression of previously acquired skills. During regression, some features are similar to those of autism. It is, hence, easy to mistakenly diagnose Rett syndrome for autism.
Signs of Rett syndrome that are similar to autism:
• screaming fits
• inconsolable crying
• breath holding, hyperventilation & air swallowing
• avoidance of eye contact
• lack of social/emotional reciprocity
• markedly impaired use of nonverbal behaviours to regulate social interaction
• loss of speech
• sensory problems
Signs of Rett syndrome that are also present in cerebral palsy (regression of the type seen in Rett syndrome would be unusual in cerebral palsy; this confusion could rarely be made):
• possible short stature, sometimes with unusual body proportions because of difficulty walking or malnutrition caused by difficulty swallowing
• delayed or absent ability to walk
• gait/movement difficulties
• microcephaly in some – abnormally small head, poor head growth
• gastrointestinal problems
• some forms of spasticity
• chorea – spasmodic movements of hand or facial muscles
• bruxism – grinding of teeth
Signs may stabilize for many decades, particularly for interaction and cognitive function such as making choices. Asocial behaviour may change to highly social behaviour. Motor functions may slow as rigidity and dystonia appear. Seizures may be problematic, with a wide range of severity. Scoliosis occurs in most, and may require corrective surgery. Those who remain ambulatory tend to have less progression of scoliosis.