The Trials and Tribulations of DNA Testing

The Trials and Tribulations of DNA Testing

Written by Kathleen Chan, OMFRC Member.  This article also appeared in our Feathers In The Wind Newsletter, February 2009.  Reprinted with Permission.

The first DNA test that I had was a DNA Sibship Analysis by Genetrack Biolabs, a Canadian company from Vancouver. It costs $495 Canadian to test two siblings. I think I paid  $250 four years ago. The test was testing 15 STR’s (which are a class of polymorphisms). The average person has no idea what the actual DNA test is measuring and cannot, therefore, understand where the results come from. The STR’s vary from population to population, but all populations have them. The average person has no idea what the range is for different populations. The results of the test are based on statistical analysis. The test lists the statistical probability that two people are half and full siblings. That was the only part of the test that made clear sense to me. Furthermore, siblingship tests are not 100% accurate, unlike paternity tests.

The second test that I had was Ancestry 2.5 by Genetree which costs $240 U.S. The test also tested 15 STR’s . The results tell you what percentage of four groups your genetic make up is from. The four groups are African, Asian, European, and Native American. There is no information about a particular tribe or country etc. The test is supposed to be designed to resolve the inter-continental origins of people. The average person does not understand how the DNA is analyzed to get the results. The method of analysis is not explained. The test simply lists the percentage of four groups that a person has DNA for.

The third test that I had was the Euro 1 by Genetree. It costs $230 U.S. . The test tells you where your DNA originates from four European areas including : South Asian, Southeastern European (Mediterranean), Northern European and Middle Eastern. The test measures 320 SNP’s (single nucleotide polymorphisms) and the method of analysis is not explained, but the results are given for a person’s European DNA. There is a second European test called the Euro 2 and it costs between $650 and $950 U.S. . It divides the Eurpoean DNA into further sub-groups. I did not do this one : due to the cost.

The fourth DNA test that I had was DNA Tribes. I did the Premium 21-Marker Test which costs $239.99 regularly. I also added the Native American and Central Asian panels for $25 each. This test gives you a list of Native and global populations and lists your tribe scores and likelihood matches.  It also provides a list of world regions where one’s ancestors are most likely to be found and provides a tribe score for these as well. The analysis is not explained, but it is done by comparing a person’s STR’s to a computer bank of between roughly 600 and 900 populations. By reading the results log, I found that some people find their results fairly accurate and others find them more confusing. The test measures autosomal DNA from both the mother and the father, but because the DNA from the mother changes slowly over thousands of years the results can be interesting. If both parents are Ashkenazi Jews from a particular country, the test might show that. It may even list different African countries or peoples. Sometimes the mixture of populations gives some strange results. Some Native Americans find their tribes listed, others have their Native DNA assigned to the nearest group like mestizo or East Asian.

I have now spent $1010.00 and I have had a small amount of Native American DNA listed on one test, but not on another. I have had a small amount of sub-Saharan African DNA identified on my last test, but not previously. I still have no idea what tribe the Native American DNA that I do have belongs to. Each DNA test provides another piece of the puzzle, but individually they do not make a lot of sense or provide a lot of information. Furthermore, the information that they do provide includes analysis and interpretation that is not fact. A DNA test is not necessarily an instant solution to a complex puzzle.

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