Huntington's disease offers a rare clean test case for brain research

Huntington's disease offers a rare clean test case for brain research

Neuroscience rarely enjoys clean experiments. Most brain disorders are mosaics of risk genes, aging, lifestyle and chance that leave their origins obscured. Huntington's disease (HD) is different. It begins with a single genetic expansion—a repeated stretch of DNA letters in the HTT gene—that is both measurable and decisive. If you inherit a sufficiently long repeat, you will develop the disease. That stark clarity makes HD scientifically invalu…