Sunday, August 2, 2015

Using Public Matches From 23andMe To Map Segments

After receiving my 23andMe results I noticed some of my matches were listed as public. I assumed this meant I could see our matching segments without asking? I was wondering where their information was located? I didn't see it in Family Inheritance Advanced. After my Countries of Ancestry information became available, a couple weeks after I received my results, I noticed you could download a spreadsheet with your matches' segment information. This information seems to be from public matches? Some of those listed on the spreadsheet are listed by first and last name. Others are anonymous. Those listed with names, and those who are anonymous, all have some information about their family's countries of origin. So the info can be useful even if there are no names attached. You can get an idea of ethnic origins of the segments. I found that I could use the chromosome start and end points at Kitty's DNA Mapper, and Genome Mate, if I added 5 zeros; plus removed the decimal point. I just added the information to my Family Tree DNA CSV spreadsheet. Then uploaded the CSV spreadsheet to Kitty's DNA Mapper
This info is especially helpful if they list a place of origin other than the United States, or any other country with a large immigrant population. Finding Irish and Nicaraguan matches has been helpful. I was able to make a segment map using Nicaraguan matches' segment data, from Family Tree DNA and 23andMe. Now I'm able to see where I've inherited DNA from my maternal grandmother.
It's a very handy feature when you've found a common surname also. I found a Browning match who hadn't got in contact with me, on the list. Nice you can access this information even if someone won't agree to genome sharing.
Nicaraguan Segment Map