Rett Syndrome

Rett syndrome, originally termed as cerebroatrophic hyperammonemia, is a neurodevelopmental 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 are not ambulatory. Scoliosis, growth failure, and constipation are very common and can be problematic.

The signs of this disorder are most easily confused with those of Angelman syndrome, cerebral palsy and autism.

Some argue that it is misclassified as an autism spectrum disorder, just as it would be to include such disorders as fragile X syndrome, tuberous sclerosis, or Down syndrome where one can see autistic features. However, it has been suggested that it be removed from the DSM-5, because it has a specific etiology.

It has also been argued that Rett Syndrome is in fact a neurodegenerative condition as opposed to a neurodevelopmental condition. This was shown by the fact that mice with induced Rett Syndrome can have their neurons completely restored and a normal phenotype by adding the MECP2 gene back to their genome. This information has also helped lead to further studies in curing or treating the disorder.

It was first described by Austrian pediatrician Andreas Rett in 1966.

In DSM-IV-TR page 76, Rett's Disorder 299.80 is listed under the broad category of Pervasive Developmental Disorders.