DNA tests

I've been asked many times about dna testing, so I thought I would briefly address the topic. The information here is by no means exhaustive, but it should be a good starting point for deciding which test to use, if you're so interested. If you notice any errors or out of date information, please let me know!

Autosomal dna (atDNA) tests analyze all of your chromosomes, and are able to determine your approximate ethnicity going back roughly 1000 years. It makes no difference whether you're male or female, the tests will search both your maternal and paternal lines. This is the test I had done, through AncestryDNA, who currently have results for more than 1,000,000 people in their database. They are able to test your entire genome at over 700,000 points, and compare to everyone else who has taken the test. As more people take the test, your percentages may change. Other companies who offer atDNA testing include 23andMe, Family Tree DNA, and National Geographic's Genographic Project. Autosomal dna results from 23andMe, AncestryDNA, and the Genographic Project may be transferred to Family Tree DNA.

Mitochondrial dna (mtDNA) tests analyze mitochondrial dna inherited from your mother. This changes extremely slowly over time, so they are able to determine your matrilineal ancestry over thousands, or even tens of thousands, of years. Even though the results are matrilineal, both males and females can be tested. Results will also show you your matrilineal migration patterns, your haplogroup (group of people descended from one common ancestor on the matrilineal or patrilineal line), and other people who have taken the test who have a genetic match to you. Companies offering mtDNA testing include 23andMe, and Family Tree DNA.

Y chromosome (Y-DNA) tests analyze the y-chromosome (Ycs) based down from father to son. Much like the mitochondrial dna, it remains relatively unchanged over time, so you can determine your parilineal ancestry over thousands, or tens of thousands, of years. Only men can be tested, since only men carry the y-chromosome, but a woman interested in tracing her patrilineal line can request that a paternal-side male relative such as a father, brother, uncle or cousin take the test. Results will show patrilineal migration patterns, your haplogroup (group of people descended from one common ancestor on the matrilineal or patrilineal line), and other people who have take the test who have a genetic match to you. Y-DNA is useful for determining the origin of your surname, since historically in western cultures, surnames get passed down from the father. Many groups have formed for specific surnames, so signing up for one of those may be a way to further your knowledge and connections on your patrilineal line. Companies offering Y-DNA tests include 23andMe, Family Tree DNA, and the Genographic Project.

Genetic testing may determine whether you carry a specific gene responsible for various diseases and illnesses. Even if you do, there is no guarantee that you will be diagnosed, it just means your chances are increased over the general population. Such genetic tests may make you aware so you can change your diet or lifestyle to minimize your risks for certain health issues, however they may also come with an unexpected cost. Since these testings are relatively new, legislation in Canada and elsewhere has not caught up to very legitimate privacy concerns. Currently in Canada, you have no legal protection if your employer or insurance company finds out that you took a genetic test and requests the results, so you are legally obligated to turn them over. As a result, your premiums may increase just on the probability that you may at some point in the future develop a certain disease. For more information on genetic testing issues in Canada, please see this CBC article, and watch the Marketplace episode mentioned in the story http://www.cbc.ca/news/health/home-dna-tests-may-affect-insurance-employment-1.3018086. Companies offering genetic testing include 23andMe and EasyDNA.

Some things to consider before ordering a dna test:

-what do you hope to find out from your dna test, which will help determine the type of test you do

-what is your budget

-what is the size of the database you are interested in -the bigger the database, the more likely you are to find a match

-privacy concerns

I chose to go with AncestryDNA, partly because I am an Ancestry subscriber and am therefore able to avail of all their features for my results, but also because I liked the price and the fact that it covered both lines of my more recent history going back about 1000 years. As a direct result of my dna test, I've been able to connect with a couple of cousins with whom I've reciprocally shared information, which has resulted in enhancing my family tree with further documentation and photographs that I otherwise would not have. I've been very pleased with my experience, and would recommend AncestryDNA to others, particularly if they already have a subscription.

If you've had your dna tested and want to share your experience, please comment!