Ashkenazi Jewish Heritage and Genetic Risk
Many Jewish people who trace their ancestors to central or eastern Europe have Ashkenazi Jewish heritage. There are now Ashkenazi Jews all over the world, but centuries ago this population lived in one area and were isolated from other populations of people. Because of this, Ashkenazi Jews can trace their ancestors back to a small group of people. Over the years, genetic traits were passed down among this group with little influence from other population’s genes. There are a number of genetic disorders that are seen more commonly in the Ashkenazi population. Many couples have testing done to look for these disorders prior to having children.
Some genetic mutations increase a person’s risk of developing a cancer. There are a few genetic mutations found more commonly in the Ashkenazi population, including BRCA 1 & 2, HNPCC and APC.
BRCA 1 & 2
Mutations in the BRCA1 or BRCA2 genes occur more frequently in people of Ashkenazi heritage. If a Ashkenazi woman has inherited a mutated copy of either gene from a parent, they have an estimated 50-75% chance of developing breast cancer during their lifetime (compared to 12% for the general population). These women have a higher risk of developing ovarian cancer as well – 30-50% in BRCA1 and 10-20% in BRCA2.
Ashkenazi men who inherit BRCA 1 or 2 mutations are also at increased risk of developing breast cancer.
Ashkenazi Jews with these mutations may also have an increased risk for developing pancreatic, prostate and skin cancer.
HNPCC & APC
Two genetic mutations associated with Ashkenazi heritage are linked to gastrointestinal cancers:
APC (Adenomatous Polyposis Coli) – causes an increased risk of colon cancer. This mutation is found in about 6% of Ashkenazi Jews. Their risk of colon cancer is about double that of the general population. APC is typically associated with hundreds of polyps, but this is not seen in Ashkenazi Jews with APC mutations.
HNPCC (Hereditary Nonpolyposis Colorectal Cancer or Lynch Syndrome) – increases the risk of colon cancer at a younger age (<40). HNPCC is also associated with several other cancers, including endometrial, gastric, ovarian, small intestine, bile duct, pancreas, brain and ureters.
People with Ashkenazi heritage should discuss their family history with their healthcare providers to explore the option of genetic testing. Finding out about a genetic mutation can be scary. The information allows you to take steps to prevent certain cancers through lifestyle choices, screening, medications and surgical procedures to reduce risk.
Resources for more information
National Cancer Institute: The Genetics of Cancer
Sharsheret: A national organization that provides community and education for young Jewish women with breast cancer.