Rett syndrome is caused by a gene mutation. Rarely, it's inherited. Infants seem healthy during their first six months, but over time, rapidly lose coordination, speech, and use of the hands. Symptoms may then stabilize for years.
In this Oct. 15, 2012 photo, Melissa Ehli, left, physical therapist assistant, sits with Maryjane "MJ" Luntz, 5, to help her with her posture while Registered Occupational Therapist Amy Tran, right, encourages her to place the peg in the correct hole as Speech Language Pathologist Partty Welling signs the word pink at Building Block Rehabilitation in Fairbanks, Alaska. Luntz has Rett Syndrome, a disorder of the nervous system that leads to developmental reversals.