Rett’s syndrome is a serious neurological disease that affects women in most cases. The disease is congenital, although not immediately evident, and manifests itself during the second year of life and in any case within the first four years. It affects about one in 10,000 children. Severe delays in language acquisition and in the acquisition of motor coordination can be observed. Often the syndrome is associated with very severe mental retardation or complete mental absence. The loss of performance skills is generally persistent and progressive. Rett syndrome causes severe ailments on many levels, making those affected dependent on others for life.