We all carry the same genes. Some of those genes are responsible for cell division in certain areas of our bodies.
Depending on the mutation carried, a person may also be at risk of on or more types of cancer.
Risky genes cause a high risk of breast, ovarian and prostate cancer and slightly higher risk of some other types of cancer.
This type of hereditary cancer is a relatively new science. Hereditary breast cancer was discovered first, in 1995, with mutations in the BR(east)CA(ancer)1 gene. Soon after mutations were discovered in the BRCA2 gene and it became known that other types of cancer were also caused by mutations in these two genes. For years researchers focused only on the BRCA genes. More recently, additional types of cancer and genes were discovered. However, because the BRCA genes were the first and only genes studied for so many years, most of the available information today is still based only on those genes. Also, because there are so many different mutations within these genes, data is reported in broad averages, and changes often as researchers learn more. This means cancer risk statistics can vary widely, depending on the source. Personal cancer risk can fall well below or above reported average ranges.
Personal cancer risk must be determined by a trained professional. Cancer risk is based on the gene that is mutated, the type of mutation within that gene, the number of first-degree relatives with cancer, their ages and a variety of other factors.
Learn more about additional cancer risk factors
Some ethnic groups are known to have a higher chance of carrying certain risky genes than in the general population. For example, people of Ashkenazi (Eastern European) Jewish ancestry have a 1 in 40 chance of carrying one of three founder BRCA mutations associated with that population. Other ethnic groups include, but are not limited to: French Canadian, Bahamian, Polish, Icelandic and African American.