Within this web site, the term "cause" is synonymous with "explanation". That is, a cause is an explanation, or a partial explanation, of why something (such as HD) occurs.
Diseases are complex processes, and individuals with HD have many diverse experiences with the disease. Just as there is no single "HD experience" (exact age of onset, severity of symptoms, etc.), there is no single cause of HD. Despite the fact that a single gene is the major factor determining whether or not an individual will get HD, other factors play a role in an individual's particular disease experience. Although genes predispose individuals to diseases, it is the combination of genes and environment (including the internal environment of an individual's body) that leads to the particular disease experience of an individual. Thus, there is not one cause of HD; instead, each person's experience with the disease has many explanations.
Last Modified: 9-18-02