The symptoms of Huntington's Disease usually appear between 30 and 50 years of age. But there are exceptions to this.
About a quarter of the people affected by HD develop physical symptoms after they turn 50. This is much later than the usual age of onset for HD. The disease may progress more slowly in people who develop HD later in life and their symptoms may be less severe.
Additionally, a very small percentage of people develop the disease before they turn 20 or even when they are children. This is called "juvenile onset" Huntington's Disease.
Seeing a doctor who is experienced in the diagnosis and treatment of neurological disorders is the best way to resolve questions about onset or any other aspect of Huntington's Disease.
[This page is based on the Association's publication Huntington's Disease. Originally written by Dennis H. Phillips, Ph.D. and first published in 1981, it has been frequently revised and republished since then. The current edition was published in 2001. (Australian Huntington's Disease Association (NSW) Inc.Huntington's Disease West Ryde, 2001.)]