DNA Question: How can I tell matches from my mother’s and father’s side apart?

We took a poll of questions AncestryDNA members had about their test results, and this one topped the list: How can I tell my paternal from my maternal matches? This is one area where testing multiple family members can help—and there’s no better time than the holidays for getting family on board.

Starring: Your Parents

Obviously, the easiest way to separate matches into your mother’s and your father’s sides is to test both parents, if you can. Once you link their results to your tree, you will automatically see a new Mother and/or Father filter option at the top of your match list page next to the Hints, New, and Starred tabs.

That means, if you have tested your mother you click the filter to see all the matches you share with her, narrowing down which DNA cousin matches probably belong to that side of the family. Same goes for the Father filter.  (Learn more about using match filters.)

A tip if you’re able to test only one parent: Sort your matches by that parent with the filter. Then click the star icon on the left side of all the matches that show up. That way you know matches without a star most likely belong on the other side of your family.

Halfway There

Don’t forget your own half-siblings.  Shared matches between you will be from the same side of your family tree as your common parent.

Find a Surrogate

Obviously, nobody can ever take Mom’s place (just ask her). And because genetic inheritance is random, unless your parent has an identical twin, a sibling is not going to be a perfect stand-in, but it’s a good start. Have an aunt or uncle test, then sort your shared matches.

The ones you share will most often come from that side of your family tree. Again, you can use the star or note feature to mark these matches.

The More the Merrier

If you’re trying to create a surrogate DNA profile for a parent, a brother or sister isn’t a perfect one-for-one replacement, but testing multiple siblings can help you build up a better substitute profile for a missing parent. And it’s fun to share and compare differences in results, to boot.

Surrogates Work for Grandparents (and Other Relatives), Too

My paternal grandparents passed away long before autosomal DNA testing was available—or maybe even thought of. But they had four children. Each of them inherited 50% of each parent’s DNA, so by testing all four of them, I should have a pretty good profile of their parents’ DNA. Which means between the four of them, I have a good chance of finding most of the matches in the database that would have matched with my grandparents—and one side of my tree.

Buy a DNA test for yourself or for another family member here.