5-10% of women have inherited genes which increase breast and ovarian cancer risk. These genes are called BRCA1 and BRCA2.
BRCA1 and BRCA2 are human genes that produce tumor suppressor proteins. These proteins help repair damaged DNA and, therefore, play a role in ensuring the stability of the cell’s genetic material. When either of these genes is mutated or altered, such that its protein product either is not made or does not function correctly, DNA damage may not be repaired properly. As a result, cells are more likely to develop additional genetic alterations that can lead to cancer.
A harmful BRCA1 or BRCA2 mutation can be inherited from a person’s mother or father. Each child of a parent who carries a mutation in one of these genes has a 50 percent chance (or 1 chance in 2) of inheriting the mutation. The effects of mutations in BRCA1 and BRCA2 are seen even when a person’s second copy of the gene is normal.
But cancer experts have not been too sure about what the real risks are of developing breast or ovarian cancer if a woman carries one of these genes.
Now, for the first time, there are reliable statistics – and it seems there’s more to it than just carrying the mutated gene.