What's Rett? 

Rett Syndrome is a genetic neurological disorder that occurs almost exclusively in girls.  After birth, girls with Rett syndrome have 6 to 18 months of apparently normal development before experiencing severe, rapid degeneration resulting in problems with language and communication, learning, coordination, eating and other brain functions. Girls can ultimately lose the use of their hands, walking ability and speech.  Other signs and symptoms that can develop include breathing abnormalities, seizures, scoliosis, and sleep disturbances.