Rett syndrome is a unique postnatal neurological disorder that is first recognized in infancy. It almost always occurs in girls but in rare cases, can be seen in boys. It is most often misdiagnosed as autism, cerebral palsy, or non-specific developmental delay. Rett syndrome is caused by mutations on the X chromosome on a gene called MECP2. There are more than 200 different mutations found on the MECP2 gene. Most of these mutations are found in eight different “hot spots.” Rett syndrome strikes all racial and ethnic groups, and occurs worldwide in 1 of every 10,000 female births. It is not a degenerative disorder.