Determining if match is paternal or maternal?

4

I am trying to understand my Gedmatch results for a female that Ancestry.com lists as a second cousin. We have a 112.4 cM X-DNA match and a 224 cM autosomal match.

Does this validate that it is through her father or is her mother still a possibility?

Quintina Smith

Posted 2016-05-01T04:33:50.083

Reputation: 41

If you have other cousins tested, and you know which side they're on, you could triangulate with them. I haven't used GEDMATCH myself yet, so maybe someone who has can incorporate this idea into a proper answer. – lkessler – 2016-05-03T05:55:50.423

Answers

5

Based on the information given, the match could be on either the paternal or maternal side.

A woman has two X-chromosomes, and she inherits an X-chromosome each from her mother and father. Of course her autosomal DNA is 50% from her mother and 50% from her father.

Without further information and analysis, such as matching those segments with other cousins, there is no way of knowing whether the match is from the mother or father. If you have other matches on that same X-chromosome, and you know which side of the family they were on, then this match must also be on that side. For example, if you have another match on the same X-chromosome for a first cousin on your mother's side, then you know that any matches on this X-chromosome must also be from your mother's side.

Harry Vervet

Posted 2016-05-01T04:33:50.083

Reputation: 17 763