Hereditary cancers occur when a person is born with a mutation in one copy of a gene that they inherited from either their mother or father. The gene normally protects against cancer but when it has a mutation it leads to an increased risk for cancer.
These changes can increase the risk for cancers in different parts of the body, but they do not increase risk for every type of cancer. Having an inherited gene mutation does not mean you definitely will develop cancer, but the risk is increased. More frequently cancer screenings or other preventive measures for people with inherited cancer susceptibility gene mutations are important.
People with an inherited gene mutation have a 50% chance of passing the mutation to each of their children.