What Is Huntington Disease?

Huntington disease is a rare condition that causes parts of the brain to break down, or degenerate. It is also called Huntington chorea. The disease causes rapid, jerky body movements and the loss of mental skills (dementia). Huntington disease can cause personality changes, behavior problems, and memory loss. Symptoms usually develop after age 40. There is no known cure. But treatment with medicines may help control the involuntary movements and behavior changes.

Huntington disease is caused by a change, or mutation, in a gene. If you have a parent with the disease, you have a 50% chance of getting the changed gene and the disease. But there is no way to know when you will develop Huntington disease. Some people may pass on the changed gene to a child before knowing that they themselves have the changed gene.

A blood test can show whether you have the changed gene. You may want to have genetic counseling if you are thinking of having the test. Medical geneticists and genetic counselors are experts who can explain what the test means, tell you the benefits and risks of the test, and answer your questions. But you make the decision about whether to have the test.