What is Rett syndrome?
Rett syndrome is a complex neurological disorder. It affects mainly girls. Although signs of Rett syndrome may not be initially obvious, it is present at birth and becomes more evident during the second year. People with Rett syndrome are profoundly and multiply disabled and totally dependent on others for their needs throughout their lives.
Why is it called “Rett syndrome”?
A syndrome is a group of features that occur together to characterise a medical condition. The pattern of characteristics associated with Rett syndrome was first described in 1966 by the Austrian doctor, Professor Andreas Rett.
Why does Rett syndrome occur?
Rett syndrome is genetic in origin. It is probably the most common genetic cause of profound intellectual and physical disability in girls, occurring more commonly than 1 in 10,000 female births. Recently it has been detected that a large proportion of people with Rett syndrome have a mutation, or fault, on the MECP2 gene on the X chromosome.
How is Rett syndrome diagnosed?
Rett syndrome is diagnosed through clinical diagnosis – looking for signs and behaviours. In many cases it is now confirmed by carrying out a genetic test.
Here are the typical signs:
- A short period during infancy when the child is apparently making normal or near normal progress;
- A period of stagnation in development from about the end of the first year, which lasts until regression occurs;
- A regression period when skills in speech and hand movement are reduced, which occurs between about nine and 30 months;
- Development of repetitive hand movements (wringing, patting, clapping, tapping, mouthing);
- Appearance of stiff or clumsy posture or gait;
- A normal head circumference at birth but a slowing of head growth between two months and four years approximately;
- Absence of other disease, syndrome or injury to account for the above features.
Other features which are often seen include:
- Breathing irregularities including hyperventilation, breathholding and air swallowing;
- EEG abnormalities;
- Epilepsy – over 50% of people with Rett syndrome have some form of epileptic seizure at some time;
- Increasing muscle tone with age. Muscles become increasingly rigid, joint deformities and muscle wasting may occur;
- Unsteady wide-based gait (about half of those with Rett syndrome achieve independent mobility);
- Development of scoliosis (curvature of the spine);
- Growth retardation.