Rett syndrome is a progressive neurological disorder seen almost exclusively in females. The most common symptoms include decreased speech, mental retardation, severe lack of coordination, small head size, and unusual hand movements.

Dr. Andreas Rett first reported females with the symptoms of Rett syndrome in 1966. Females with this X-linked dominant genetic condition are healthy and of average size at birth. During infancy, head growth is abnormally slow and microcephaly (small head size) develops. Babies with Rett syndrome initially have normal development. At approximately one year of age, development slows and eventually stops. Patients with Rett syndrome develop autistic features. Involuntary hand movements are a classic feature of Rett syndrome.

Females with Rett syndrome may also develop seizures, curvature of the spine (scoliosis), irregular breathing patterns, swallowing problems, constipation, and difficulties walking. Some females with Rett syndrome are unable to walk. There is currently no cure for...