Rett Syndrome Overview
Rett syndrome is a neurological disorder identified in 1965 by Dr. Andreas Rett. The cause of Rett Syndrome, a brain disorder primarily striking girls after a period of early normal development, has been traced to a defective gene on the X chromosome. The gene, called MECP2 ("meck-p-two"), plays a significant role in "silencing," or turning off, other genes. Rett syndrome is the first human disease found to be caused by mutations in this type of gene. Studies have found the prevalence of Rett syndrome to be from 1:12,000 to 1:15,000 live female births.
A research team led by Dr. Huda Y. Zoghbi, a Howard Hughes Medical Institute (HHMI) Investigator at Baylor College of Medicine in Houston, reported this discovery in the October, 1999 issue of the scientific journal Nature Genetics. They collaborated with Dr. Uta Francke, an HHMI Investigator at Stanford University School of Medicine.
The National Institute for Child Health and Human Development and the International Rett Syndrome Association funded Zoghbi's research. The Blue Bird Circle Rett Center of Baylor College of Medicine, directed by Dr. Daniel G. Glaze, provided a number of patients for the study.
The child with Rett syndrome develops normally up to around six to eighteen months of age, with some children beginning independent walking. They then enter a period of regression, during which they lose the purposeful use of their hands, replacing it with constant repetitive hand movements. Girls and women with Rett syndrome have impaired or lost communication and motor skills and possibly mental retardation. They remain dependent on others for their care. However, the clinical course of Rett syndrome is not that of a degenerative disorder and, over time, individuals with Rett syndrome may demonstrate improvements, for example in communication skills.
- Normal development to 6-18 months
- Progressive loss of skills with loss of speech and hand function usually preceding gradual loss of cognitive function
- Ultimate level of functioning reflects profound mental retardation in all intellectual domains
- Acquired microcephaly, growth retardation, and decreased weight gain
- Stereotyped hand-clasping, hand-wringing, or hand washing movements are present in every case; tooth-grinding and breath-holding are also common
- Gait deteriorates and is characteristically ataxic; some may become nonambulatory
- Language is generally absent
- Eye contact is present
- Child shows little interest or ability in manipulating objects
- Seizures develop in 75% -80% of the population between ages 1 and 3 yr.
- Behavior modification techniques do not significantly impact target behaviors
- The syndrome occurs only in girls