Sometimes DNA can reveal an ugly truth. A reader, let’s call her Patty, asked me for help explaining the unusual looking comparison of her DNA test results with her uncle Bob’s results. The surprising thing was the large number of green bars that she saw in the GEDmatch one to one comparison, indicating fully identical segments (FIRs), almost as many as a full sibling would have. How could that be?
Of course my first thought was that Bob is actually her full brother, that her mom, Janet, had a child out of wedlock who was raised by the child’s grandparents, Mona and Dick, as their son. This has happened in many a family. But that was not the backstory. Janet was a small child when her brother Bob was born. Bob and Patty also share just one segment of 27 cM on the X chromosome, which, of course, would be normal for a maternal uncle but low for a brother. Have a look at the comparison image from GEDmatch for chromosomes 1-22:
Thoughts? Usually only full siblings or double first cousins will have numerous fully identical segments, so what could this be? Obviously Patty’s dad would also have to be a close relative of Bob’s for there to be so many FIRs. A full sibling would usually show even more of them, however.
Personal DNA test kits are only $69 in the summer sales at three of the major vendors: Ancestry.com, Family Tree DNA, and MyHeritage. So which one to do? Well that depends on your objectives. If you are testing for the fun of it, then maybe Ancestry with the largest database and automatic tree matching is the one for you. I have lots of details on why to pick one or another in my page of DNA test comparisons.
But beware, if there are any family secrets such as your dad or grandad not being whom you expect or an out of wedlock child, DNA will out them. Recently an amazing story where DNA revealed a surprise was reported in the Washington Post. The tester’s Dad was switched at birth in the hospital!
Another warning is that the science of figuring out where your ancestors are from via DNA is still in its infancy. They really cannot tell the difference very well between German or Scottish ancestry, both can look Scandinavian or English, click here to read my blog post on that topic. They do fine with broad continental predictions. Also some ancestry is very distinctive, so easy to predict, like Finnish or Ashkenazi or Subsaharan African. However Native American may show as East Asian and gypsy might be South Asian.
If your ancestors are recently from Europe then you might have better luck finding cousins at one of the other companies besides Ancestry. Very few Germans in Germany have tested and those few are mainly at Family Tree DNA. Of course you can upload your autosomal DNA results from the other companies to Family Tree DNA.
If your ancestry is from the British Isles you might consider testing at Living DNA currently on sale for $119. This gives a detailed county by county break down in Britain of your ancestry and seems fairly accurate. Plus they are also making a push to get Germans to test.