An example of an inherited risk of cancer is Lynch syndrome. A person with Lynch syndrome has an elevated risk of colorectal, endometrial, stomach, ovarian, urinary tract, other intestinal cancers, and additional cancers.
The increased risk is due to a mutation in one of several genes that fix mistakes made when DNA is copied. These genes are called DNA mismatch repair genes. The body has many mechanisms that work hard to prevent DNA copying errors and protect against cancer.
When one of those mechanisms is disabled by mutations, cancer is more likely to occur and at a younger age.
Lynch Syndrome Ireland 