Rett Syndrome

Definition: Rett syndrome, a childhood neurodevelopmental disorder, is considered to be part of the autism spectrum. Unlike the other autism spectrum disorders, Rett syndrome almost always affects girls. Loss of muscle tone is usually the first symptom. Other early symptoms may include problems crawling or walking and diminished eye contact. As the syndrome progresses, girls lose purposeful use of their hands and the ability to speak. Compulsive hand movements such as wringing and washing follow the loss of functional use of the hands. Over time, most girls affected with Rett syndrome will lose most of their ability to perform ordinary activities; even eye gaze and speech are affected.

Rett syndrome looks similar to other autism spectrum disorders, though loss of muscle tone is far more common in Rett syndrome than in other autism spectrum disorders. While the cause of most autism spectrum disorders is unknown, researchers have discovered the cause of Rett syndrome. About 80% of girls affected have a genetic mutation, and a genetic test can confirm the diagnosis. The test involves searching for the MECP2 mutation on the child's X chromosome.

_Sources:

NINDS Rett Syndrome Information PageOffice of Communications and Public Liaison, National Institute of Neurological Disorders and Stroke, National Institutes of Health. Bethesda, MD.

Rett Syndrome Fact Sheet Office of Communications and Public Liaison, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD.

Pronunciation: Reht Sin-drom