If you have one or both of your biological parents genotyped with 23andMe, DNA Relatives can determine whether a match shares DNA in common with both you and one of your parents, and therefore is likely to be on either your mother’s side or your father’s side. This can help narrow your search if you’re looking for a common ancestor with one of your matches, and using Map View, you can look for differences in where in the world matches on the two sides come from.
How it works
This feature labels relatives that share DNA in common with both you and your parent. If your relative also shares DNA with your mother, he or she is most likely on your mother’s side of the family. Conversely, if a relative shares DNA with your father, he or she is probably on your dad’s side. This is the case for both male and female relatives, since DNA Relatives is based on your autosomal DNA.
When you are sharing genomes with or on the same account as one or both of your parents, DNA Relatives will check to see what matches you share in common with each parent. You’ll see this indicated next to each match in your DNA Relatives list. You can filter your matches by which side of the family they’re on:
|M labeled relatives match both you and your mother|
|P labeled relatives match both you and your father|
|Full siblings show DNA shared with both parents|
|Some more distant matches may not receive labels if they do not appear on either parent's DNA Relatives list|
If you only have one parent in the system, you’ll be able to use the filters to show only people who match that parent, or only people who do not match that parent. In many cases, a relative who doesn’t match your father matches your mother, so you can find relatives from both sides even if only one parent has been genotyped.
Occasionally, you’ll find relatives that match both your mother and your father. For instance, a sibling should be related to both your parents. This can also happen if the same person happens to be distantly related to both of your parents.
You may also find relatives that don't match either of your parents. Since all the DNA you have comes from either your mother or father, it is biologically impossible for one of your relatives to not share DNA with one of your parents. In these cases, the amount of DNA shared likely falls just short of the DNA Relatives detection threshold.