Rett syndrome is a childhood disorder considered to be on the autistic spectrum. It primarily affects girls who had been previously developing normally until the age of six to 18 months.
Rett syndrome is neurological, meaning it affects the brain and nervous system. It is developmental, which means that in this childhood disorder, normal development from infancy onward is disrupted, and may regress.
In the Early Onset Phase, normal development stops, and the decline begins. Loss of muscle tone (hypotonia) may be the first symptom to appear. Eye contact lessens, as does the abiity to communicate with others.
Language and walking skills deteriorate. Normal use of the hands is replaced by compulsive and repetitive movements.
In the Rapid Destructive Phase, usually between a year and four years of age, regression can be quick or it may be gradual. Markers of being on the autistic spectrum may flourish, with a diminishing ability to interact socially or communicate with others.
The child may walk on their toes, with a wide gait. They may have trouble chewing and grind their teeth. They may have problems with breathing and with sleep.
Heart problems with irregular heartbeat is common. They may experience seizures. Cognitive dysfunction, including learning disabilities, become more severe.
In the Plateau Phase, the regression slows down. There may be improvement. Many past indicators of being on the autistic spectrum may decrease.
The child may show an increased interest and ability to interact socially. They may exhibit a greater awareness of their surroundings, becoming more alert, and better able to communicate with others.
This is usually the level where most of those who have Rett syndrome will live out their lives.
In the Late Motor Deterioration Phase, stiffness or conversely loss of muscle tone and laxity, may increase. Scoliosis (curvature of the spine) affects about 80 percent of those who have Rett syndrome. In the most severe cases, the individual may eventually become unable to move.
Most people with Rett syndrome will live to be in their 50's or 60's. Death is often the result of pneumonia.