Rett syndrome

Rett syndrome A neurological disease that affects girls only and is one of the most common causes of mental retardation in females. Girls with the syndrome show normal development during the first 6 to 18 months of life, followed first by a period of stagnation and then by rapid regression in motor and language skills. The hallmark of Rett syndrome is the loss of purposeful hand use and its replacement with stereotyped hand wringing. Other symptoms include slowed brain and head growth, seizures, and gait abnormalities. Rett syndrome is an X-linked dominant trait and is due to mutation in the MECP2 gene on the X chromosome. The vast majority of cases are sporadic and result from a new mutation in the girl with Rett syndrome. Males with MECP2 mutation suffer severe brain disease and die shortly after birth. See also X-linked dominant.