Hereditary cancer occurs when inherited genetic changes, called mutations or disease-causing variants, cause a problem with cell growth. Everyone has about 6-8 genetic changes and, much of the time, these are harmless. However, certain mutations increase risk of cancer or other genetic disorders. Furthermore, some mutations are particularly common among people who share the same ethnicity.
Individuals of Ashkenazi Jewish descent are about 10 times more likely than the general population to have a BRCA gene mutation, which increases the risk of breast cancer in both women and men, ovarian cancer, prostate cancer, and pancreatic cancer.
Overall, about 1 in 40 Ashkenazi Jews carries a BRCA mutation.