Overview of Rett Syndrome

Rett syndrome (RS) is a neurodevelopmental disorder that occurs almost exclusively in females. RS progresses from the onset of symptoms to a more complete expression of the disorder; it does not worsen once the child has reached "symptomatic plateau." RS is not a degenerative condition.

Rett syndrome was originally described by Dr. Andreas Rett of Austria in 1966. RS became known worldwide two decades later following publication of a report describing 35 affected girls from Sweden, Portugal, and France (Hagberg et al., 1983).

Infants and children with RS usually develop normally until approximately age 6 to 18 months. They may then cease to acquire new skills and gradually or suddenly lose previously acquired abilities (developmental regression), such as conscious control of the hands (purposeful hand movements) and the ability to vocalize most sounds or words. Acquired hand and finger use is gradually replaced by repetitive, uncontrolled hand movements including hand clapping, mouthing, or "washing and wringing." Children may also develop autistic-like behaviors, an impaired ability to perform the motor movements required for coordinating walking (gait apraxia) and trunk movements, breathing irregularities during waking hours, seizures, feeding and swallowing difficulties, and growth retardation. Over time, certain motor control difficulties may worsen, whereas other associated symptoms may tend to stabilize or improve. Rett syndrome has been found to be caused by mutation in the gene encoding methyl-CpG-binding protein-2 (MECP2). This gene is located on the X chromosome and, in some cases, may be transmitted as an X-linked dominant trait. Other mutations may be sporadic in nature.

	Symptoms/Findings/Clinical Course