ese families have up to a 90 percent lifetime risk of developing breast cancer, and it is estimated that more than half these women will be found to have breast cancer by the age of 50 and more than 85 percent by the age of 70. In some families, those with BRCA 1 alterations have a higher risk of developing both breast and ovarian cancers. Women with this gene alteration tend to develop breast cancer at an earlier age than women in the general population, but the disease can also occur in older women with BRCA 1 alterations. Some, for that matter, never get the disease at all, so it is not a certainty by any means. The risk of developing cancer may depend on the specific type and alteration of the gene. Men also inherit the gene, but those who do do not seem to have an increased risk of breast cancer, though they can pass the gene on to their children. There is some evidence for a slight increase in the risk of increased prostate cancer, however.
The existence of heightened breast cancer susceptibility among women with this gene has been known for several years, based on family and other studies. Only recently, though, have scientists managed to isolate and "clone" the gene, meaning pinpointing its exact location and making copies of it in the lab. The gene is inherited in a mutated form in some families, and women who inherit the mutated form, as noted, are highly susceptible to breast and ovarian cancers. The isolation of the gene has implications for the detection and prevention of breast cancer, and when a test for mutations is made available, women will be able to find out whether they carry the mutated gene. A long-term goal of genetic research in this area is to discover a method to correct or mitigate the damage done by genetic alterations, and this discovery may assist in this effort.
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