I did this because my Grandma Gert always said we were part American Indian, but she drank so we never quite knew what to believe. Well turns out she was fibbing so my results were as expected (Polish and Irish) with the exception of being a teeny percentage Ashkenazi Jewish, something I’d never even heard of before.
My oncologist told me that many many people of European descent have at least a bit of Jewish ancestry. Given the centuries of persecution and forced dispersion, many Jews found it safer to “pass” or otherwise keep their Jewish background private, and eventually that family knowledge is lost. Remember former Secretary of State Madeleine Albright, who had no idea her parents had converted from Judaism? That has been happening for centuries.
Hidden or forgotten genetic background can turn out to be critical when it comes to diagnosis and treatment of diseases that tend to cluster in particular genetic groups. For instance, the BRCA genes associated with high rates of breast and ovarian cancer tend to be found in Ashkenazi Jews. When those genes were first identified, oncologists tended to test only patients known to have an Ashkenazi Jewish background for the gene. However, given that we now know that many Europeans have at least a smidgen of Jewish ancestry, oncologists now BRCA test far more patients, even those who have no known Ashkenazi ancestry. Even that smidgen could be enough to pass the BRCA gene along. A positive BRCA status is an important factor when putting together a treatment plan for the cancer patient, but can also function as an early warning for other family members to get tested to see if they are at risk.
I love this genetic stuff.