A moving personal narrative about a family confronting Huntington's disease, interwoven with a journalistic account of the biomedical research that found the gene responsible and may one day find the cure. In 1968, Wexler's mother was diagnosed with Huntington's disease, a devastating neurological illness that often leads to madness and is always fatal. Historian Wexler (Occidental College; Emma Goldman, 1984) then learned that she and her sister, Nancy, each had a 50 percent chance of inheriting the disease from their mother. While Wexler's father organized the Hereditary Disease Foundation to support Huntington's research, and her sister became a researcher, Wexler felt shame over her failure to get as actively involved. She reports that her own diary, one ``obsessed with self-analysis,'' rarely mentioned Huntington's and then only in connection with her mother, never with herself. For years, the family watched Wexler's mother's progressive deterioration, and the daughters watched themselves for symptoms. A research breakthrough in 1983 led to a predictive test that could identify those who would develop the illness years before any symptoms appeared. In the most gripping part of the book, Wexler describes her feelings about living with uncertainty and her decision not to take the test. The research story, which makes up a large portion of the book, is less compelling than the personal one, but the account of fieldwork in a village in Venezuela where nearly every family has members with Huntington's is fascinating. Wexler is at her best when writing about human beings. At one point she speaks of her sister as having ``the insight of a woman at risk, who understands emotionally as well as intellectually the tremendous costs of this illness.'' The same may be said of Wexler. A revealing memoir that tells as much about living at risk as it does about Huntington's.