Huntington's disease is a disorder passed down through families in which nerve cells in the brain waste away, 或者 degenerate.
Causes, incidence, and risk factors
American doctor George Huntington first described the disorder in 1872.
Huntington's disease is caused 由 a genetic defect on chromosome #4. The defect causes a part of DNA, called a CAG repeat, to occur many 更多 times than it is supposed to. Normally, this section of DNA is repeated 10 to 35 times. But in persons with Huntington's disease, it is repeated 36 to 120 times....