Huntington's chorea was first described by American physician George Sumner Huntington (1850–1916). Now called Huntington’s disease, it affects about 1 person in 20,000 and occurs all over the world. It is an inherited condition.
Chorea means involuntary twitching movements of the face, and jerking, flicking or fidgety movements of the limbs and body. These move from one area of the body to another. Huntington’s disease also features alternating periods of aggression, anger, excitement and depression, and progressive loss of memory and personality Dementia).
These psychiatric disturbances may appear before the movement disorder or may develop later.
Symptoms appear between the ages of 30 and 50, and so can be passed on in the genes before any signs appear. It progresses for ten to thirty years. At present there is no known cure.
The cause is a defective gene. The defect affects the production of certain brain enzymes, which are proteins involved in making essential brain chemicals. With each pregnancy involving the gene-carrier as a parent, there is a 50:50 chance that the defective gene will be passed on.
The enzyme deficiency causes a progressive loss of nerve cells in certain parts of the brain, (causing intellectual and mood problems) and a build-up of the brain chemical dopamine (causing the movement problems).
Genetic testing can show whether or not someone has the disease, if the diagnosis is in doubt. Children of a person with Huntingdon’s disease can be offered the gene test to see if they will develop the disease. The gene test can also be done on an unborn baby early in pregnancy.
At present there is no cure. Drug treatment can lessen the disturbed movements (chorea).
The psychiatric and behavioural disturbances seriously affect the quality of life of the person and the surrounding family. The progressive movement disorder makes everyday life increasingly difficult until continuous nursing care is required.