RETT SYNDROME

Introduction

Rett Syndrome is a profoundly handicapping neurological disorder which only affects girls. Its diagnosis is presently a clinical one, and depends upon the recognition of regression in behaviour and some physical changes, usually after nine months of age. There is a reduction in the rate of head growth and loss of manipulative ability, which is replaced by characteristic hand-wringing movements, usually by the age of four years.

Although first identified in 1966 by Andreas Rett in Vienna and recorded in a small German publication, Rett Syndrome went largely unnoticed until 1983, when it was rediscovered by Professor Hagberg, of Sweden, and his colleagues, whose findings were reprinted in a widely-read English language neurology journal. Since this time, a great deal of new biochemical, physiological, and genetic data has been presented at many conferences world-wide. This syndrome has been independently recognised throughout the world, and probably occurs in more than one in 10,000 female births.

Diagnosis

Diagnosis is clinical, dependent upon the co-existence of three groups of features:

• a history of slowing of development, always followed by loss of previously acquired skills
• marked changes in emotional development and behaviour, especially withdrawal and anxiety
• emergence of a variety of stereotyped behaviours, most commonly involving the hands and breathing patterns

Causes

Rett Syndrome is thought to be a genetic disorder in which a fault (mutation) develops, affecting a gene on the X chromosome. As it is a random event, such a mutation rarely occurs a second time in the family. Chemical abnormalities have been found in the areas of the brain which co-ordinate movement and thinking (a clue as to how the gene influences these processes). Further research is essential if both the cause and treatment of the disorder are to be found.

Symptoms

Although these are the main symptoms, not all girls show all of these signs:

• loss of previously acquired skills after initial progress
• regression in social development (this can be confused with autism)
• loss of purposeful hand use
• development of repetitive hand movements (wringing, patting, clapping, tapping, mouthing)
• severe learning difficulties
• slowing of head growth with age
• hyperventilation and/or breath holding, and/or air swallowing
• grinding of teeth
• grimacing of the face and other non-purposeful body movements
• unsteady wide-based, stiff-legged gait (about half achieve independent mobility)
• muscle wasting
• small cold feet
• increased "spasticity" with age (muscles become increasingly rigid, and joint deformities are liable to occur)
• a tendency to decreased mobility with age
• scoliosis (curvature of the spine)
• epilepsy (50% may suffer some form of fits at some time)

Development

At first, there is a short period during infancy when the child makes normal or near normal progress. There follows a period of stagnation in development from the end of the first year, which lasts until regression occurs (known as stage 1). Next comes a regression period when skills in speech and hand use are lost, which usually occurs between 9 and 36 months (stage 2). Lastly comes a life-long stable period in which learning continues, although motor handicaps are apt to increase (stages 3 and 4).

Treatment

Research is in progress to find specific treatment for the symptoms of Rett Syndrome. Many of the drugs used in other handicapping conditions have a place in the management of Rett Syndrome.

Physiotherapy can greatly help the girls, not only by preventing stiffness and deformities in the joints, but also by encouraging movement, walking, and toning of the muscles. Hydrotherapy, and more recently, underwater jet massage are also of great use. They help to encourage relaxation and movement, thus minimising joint deformities. Various pieces of equipment and aids, tailored to suit the individual requirements of the girls, can greatly them (e.g. braces to arrest scoliosis, splints to modify the hand movements, and individualised wheelchairs to give a good sitting position).