Rett syndrome
Overview
What is Rett syndrome?
Rett syndrome is a progressive neurodevelopmental disorder that most often happens in females. It is characterized by typical development for the first 6 to 18 months of age and then a loss of acquired skills, loss of speech, and development of stereotypic movements. Individuals with Rett syndrome may have a small head, seizures, and intellectual disability. Rett syndrome is the second most common cause of severe intellectual disability after Down syndrome. Individuals with Rett syndrome also develop motor disorders and are prone to anxiety, sleep disorders, and orthopedic problems.
http://www.omim.org/entry/312750
https://www.rettsyndrome.org/document.doc?id=168
http://rarediseases.org/rare-diseases/rett-syndrome/#supporting-organizations