Problems with AncestryDNA’s Genetic Ethnicity Prediction?

I’ve received a number of emails and comments (see, e.g., here) complaining about Ancestry.com’s new test, AncestryDNA.  Specifically, several test-takers believe that the Genetic Ethnicity Prediction provided by Ancestry.com does not reflect the numbers that they expected based on their own research.
For example:

“I just got my DNA test results back from Ancestry.com and I am concerned. I was born in England and I have gone back many generations and have found that all my ancestors as far back as the 1600′s in most cases are English.  According to the results I have no British Isles DNA. It states that I have 60% Central Europe, 30% Scandinavian and 7% Southern Europe. I also have 3% unknown. How can this be?”

“Just received my results: 21% Southern European and 79% Central European which doesn’t follow years of work on my family history.”

Do these comments reflect errors in AncestryDNA’s Genetic Ethnicity Prediction, or are there other factors at play?


Although I am not privy to the ‘behind-the-scenes’ at Ancestry.com, I don’t believe that there are serious issues with AncestryDNA’s Genetic Ethnicity Prediction.  Ancestry.com’s DNA arm has a solid scientific team and a large and valuable reference database.

Indeed, Ancestry.com is well aware of the limitations and challenges that their Genetic Ethnicity … Click to read more!


GEDmatch.com Adds Phasing Tool

Today (or perhaps yesterday?) popular DIY genomics website GEDmatch.com released a new tool for phasing DNA data.  Listed under a link entitled “Generate phased data file,” the tool allows users of the GEDmatch.com site to phase their chromosomes if they have their parent’s raw data.

(A similar tool was previously created by David Pike at http://www.math.mun.ca/~dapike/FF23utils/; with David’s tool, users receive their results directly and do not need to upload their DNA test results; accordingly, users have a variety of options depending on their privacy tolerance).

What the Heck is “Phasing”?

Currently, SNP chip testing performed by 23andMe or Family Tree DNA is unable to attribute a test result to either one of your parents.  For example, if your results for SNP rs00000 are “AG,” the test alone cannot determine whether … Click to read more!