Conditions
A severely disabling genetic disorder of neurological development, sometimes confused with autism.
What is it?
A serious and complex genetic developmental disorder occurring almost always in girls. A child who has apparently been developing normally, starts to regress and loses developmental skills previously gained. It occurs in all races and ethnic communities. It is profoundly disabling, and patients remain highly dependent.
What causes it?
It is caused by a mutation in a specific gene on the X chromosome. It is seen almost exclusively in girls. Some believe that male foetuses with the anomaly usually die before birth, but the reason for the low incidence in boys is still controversial. It is almost always caused by a new genetic mutation, in children born to normal parents.
What are the symptoms?
Development is usually normal until around 6 to 18 months. Then development, especially of language skills and movement, slows down markedly and regresses. Floppiness and loss of muscle tone may be an early sign. Effective hand movement is lost, and head growth slows, so some children have a noticeably small head. Repetitive, stereotyped hand movements are typical, such as hand wringing and washing; lower intelligence; reduced socialization; and other features may include scoliosis, the child stops speaking, difficulties in walking and an odd gait, breathing anomalies including breath-holding, hyperventilation, or sighing, gastrointestinal symptoms, including constipation, and, in some cases, seizures. The syndrome can vary in severity. After a period of regression and the development of new symptoms, the condition can stabilise, often for extended periods, with some improvements in attention, sociability, and communication skills. This is usually followed by further deterioration, especially in mobility.
How is it diagnosed?
In the early stages, it can be confused with autism, sharing some features, such as inconsolable crying, screaming episodes, avoiding eye contact and lack of social and emotional contact with others, loss of speech and general interest. It is usually diagnosed by careful history and examination, though genetic tests have recently been developed which can confirm the diagnosis in around 80% of cases. Diagnosis would usually be made by a paediatrician or paediatric neurologist.
How is it treated?
There is no cure, though such disorders may ultimately benefit from gene therapy. Treatment is, thus, symptomatic and supportive. This may include medications for epilepsy, G.I. symptoms, and anti-psychotic medicines for self-harming behaviour. Occupational therapy can be useful, and regular monitoring for potential development of heart anomalies or scoliosis is useful.
What is the prognosis?
Women with Rett syndrome can live to an age of 40. There may be heart conduction problems and sudden death.
When to call the doctor
When a child who has been developing apparently normally, starts to lose proper use of her hands, but shows odd hand movements, slowed mental growth, abnormal gait.
How can it be prevented?
It cannot be prevented.