The two genes that cause most cases of inherited breast cancer are part of the body’s “copy-editing” machinery that corrects misspellings in the genetic code inside cells, new research suggests. With the genes’ function now at least partly understood, scientists hope to develop new strategies for preventing or treating the disease.
One gene, BRCA2, helps repair genetic damage induced by ionizing radiation, such as X-rays, according to a report in today’s issue of Nature. The other so-called breast cancer gene, BRCA1, has a similar function, researchers reported earlier this year.
The two genes account for about 90 percent of inherited breast cancers - or about 5 percent to 10 percent of breast cancers overall - and a smaller percentage of other cancers. When mutated, they apparently allow genetic errors to accumulate until a cell’s growth controls break down and cancer results.
Allan Bradley, the Baylor College of Medicine scientist who led the latest work with colleagues from Lexicon Genetics of Woodlands, Tex., said breast cancers caused by the mutant genes may be especially treatable with radiation therapy, since they are hobbled in their ability to correct radiation damage.