The race is on across the world to identify the gene responsible for inherited forms of breast cancer. Scientists in Britain and the United States have discovered that the gene is located somewhere on chromosome 17, and the teams are perhaps within weeks of pinpointing the gene itself. Researchers are confident that their discovery will revolutionise our understanding of breast cancer and may also make possible the development of a genetic test that identifies women at high risk of the disease. If the abnormality can be identified early enough, the eventual development of cancer can perhaps be prevented. However, for a woman who is told that she has a 75% chance of developing breast cancer before the age of 60 this breakthrough could raise more problems than it solves.