Why do all my doctors ask if I’m Jewish? I’ve just been diagnosed with breast cancer
It has nothing to do with synagogues or religious belief!
Some genetic changes (mutations or pathogenic variants) are more common in certain groups of people than others. These mutations are referred to as “Founder Mutations”. They occur when people with the same background remain in a separate group due to religious, cultural or geographic reasons.
Some founder mutations have been passed down over hundreds or even thousands of years!
So…. why would your doctor ask you if you are Jewish if you have breast cancer?
It’s because people with Ashkenazi Jewish heritage (that is with an Eastern European background including German, Polish or Russian) are more likely to carry one of 3 specific mutations in BRCA1 or BRCA2. The risk is about 20 times higher than for the general population.
BRCA1 and BRCA2 are important genes. If they are not working properly, the risk of cancers such as breast and ovarian cancer in women and breast and prostate cancer in men, is increased. This has 3 important consequences:
- Because of the increased likelihood, genetic testing may be offered even if an individual doesn't meet the usual Medicare testing criteria.
- Genetic testing may alter your treatment choices.
- Predictive genetic testing, which is performed when a mutation has been detected in a blood relative, should include all 3 of the common Ashkenazi founder mutations.
The Ashkenazi are not the only group with founder mutations. For instance, there are 3 founder mutations in the BRCA genes in the Afrikaner population in South Africa. These individuals are descended from Dutch Huguenots who moved to South Africa in the 1650s. As the initial population group was bigger, the frequency of these mutations is lower.
If you have mixed heritage, it's important to test the whole gene, as well as other high risk genes associated with the cancers detected in you or your family