Rett Syndrome is a neurological disorder occurring primarily in girls in which individuals exhibit reduced muscle tone, autistic-like behavior, stereotyped hand movements consisting mainly of wringing and waving, loss of purposeful use of the hands, diminished ability to express feelings, avoidance of eye contact, a lag in brain and head growth, gait abnormalities and seizures. Hypotonia (loss of muscle tone) is usually the first symptom. The syndrome was first recognized in 1966 by Dr. Andreas Rett, however it was not until a paper was published by Dr. Bengt Hagberg in 1983 that the disorder was made widely known in medical circles. The syndrome affects approximately 1 in every 10,000-15,000 females with symptoms usually appearing in early childhood- between age 6 and 18 month. Rett syndrome is caused by mutations (structural alterations or defects) in the MECP2 (pronounced meck-pea-two) gene, which is found on the X chromosome. Scientists identified the gene íV which is believed to control the functions of several other genes íV in 1999.
Diagnostic Criteria: (Required for the recognition of Rett Syndrome)
- A period of normal development until between 6 íV 18 months.
- Normal head circumference at birth followed by a slowing of the rate of head growth with age (starting between 6 months and 4 years).
- Severely impaired expressive and receptive language.
- Intellectual development appears to be severely delayed, but true intelligence is difficult to measure.
- Loss of purposeful hand skills at age 1-4 years.
- Repetitive hand movements including hand washing, hand wringing, hand clasping and hand mouthing which can be almost constant while awake.
- Shakiness of the torso, which also may involve the limbs, particularly when the child is upset or agitated.
- Unsteady, wide-based, stiff-legged gait, and sometimes toe walking.
Supportive Criteria: (Symptoms not required for the diagnosis of Rett Syndrome, but which may also be seen):
- Breathing dysfunctions which include breath holding or apnea, hyperventilation, and air swallowing which may result in abdominal swelling.
- EEG abnormalities which include slowing of normal electrical patterns, the appearance of epileptiform patterns and a reduction in RM sleep.
- Muscle rigidity/spasticity/joint contractures.
- Teeth grinding (bruxism).
- Small feet.
- Growth retardation.
- Decreased body fat and muscle mass.
- Abnormal sleep patterns and irritability.
- Poor circulation of the lower extremities.
- Decreased mobility with age.