Everyone has BRCA1 and BRCA 2 genes. Some people have changes, called mutations, in these genes. One in 40 Ashkenazi Jewish women has a BRCA gene mutation.
Mutations in BRCA genes raise a person’s risk for getting breast cancer at a young age, and also for getting ovarian and other cancers. That is why Ashkenazi Jewish women are at higher risk for breast cancer at a young age. If your mother or father has a BRCA gene mutation, you have a 50% chance of having the same gene mutation.