Whether it’s an autosomal test, a Y-DNA test or an mtDNA test, virtually all providers use the same science. Some providers offer an ‘off the peg’ solution such as Ancestral Origins™ or AncestrybyDNA™, so if you’re interested in these you should shop around for the lowest price. Most providers offer a test that interprets and presents the results in a unique way, so if one of these catches your eye, look for examples of how the results are presented on their website before you buy.
I used 23&me, (who has around 80 geographical regions) and while I was disappointed with the nationality results, it was only because I thought they were a bit vague – but in all honesty, I didn’t really know what to expect, so there’s that. Now understanding a little more about the limitations of results from any company, have no problem with what I received.
As stated at the start of this guide, each one of the main tests will provide you with easy-to-use reports and cousin matching that you can use in your genealogy research. You will need to carefully review the information provided in this guide to make a decision about which test is best for your particular needs. You may also choose to test with (or upload your results to) multiple companies.
23andMe tests autosomal and mitochondrial DNA for all users, as well as Y-DNA for males. These different types of DNA play into the service’s different ancestry reports. Your geographical ancestry report stems from the autosomal DNA, which is a combination of both of your parents’ DNA. Your maternal and paternal haplogroups are derived from mitochondrial DNA and Y-DNA respectively. These show the migration of your direct parental line through thousands of years. 23andMe also identifies your Neanderthal ancestry.
There may be a couple of reasons why your son's ancestry results did not show Italian heritage. Firstly, your own result was "72% Italy/Greece", and so it is not certain how much of this percentage was Greek or Italian. The fact that your son's DNA results estimated him to be "30.5% Greek" could suggest that your "Italy/Greece" percentage was actually indicative of majority Greek heritage, and not Italian. Your son would then have inherited roughly half your Greek DNA.
Men have an X and a Y (chromosome) that are paired together. Women don’t have the Y, they just have two X’s. A child’s genes come from a mix up and recombining of the two parents. So a girl child will still end up with two X’s but some bits of them will come from the father’s X and some from the mother’s. A boy child on the other hand may have some bits of X from both mother and father, but his Y will have just come purely from his father – virtually unchanged. That makes Y-DNA such an exciting possibility for genealogy where you want to follow the paternal (surname) line. You could expect that Y-DNA will therefore pass virtually unchanged from father to son through the generations, meaning that the Y-DNA of a man’s g-g-g-g-grandfather will look very much like that of his own Y-DNA – with some little changes.
So, back to the example of the two men (lets call them John and James) we think might be brothers: We find two g-g-grandsons (or any male descendant in a direct father-son line) of each, preferably the most distant cousins we can find, and get a Y-DNA test done for all four men. Usually a 37 marker Y-DNA test is a good place to start. This looks at 37 sections of each persons DNA that the genetic scientists think are most useful for our purposes (the bits that are least likely to randomly change over generations). The results come back looking like a fairly meaningless string of numbers which are fairly useless on their own, but allow us to compare each persons result with others in the database of the testing company.
I can’t help you with your question Robin, but you make a good point. I have had my DNA tested (only with MyHeritage so far) and the “North and West European” part is so broad (it could be anything from France, Belgium, the Netherlands, Luxembourg, Germany etc but it would have been important to have more detail as it is really what I would have loved to know more about) and then 0.8% Middle East…
Your DNA information is gathered using saliva capture, which, once analyzed, is stored forever on 23andMe's servers. The service also provides for a chromosome browser and comparison, as long as any possible matches approve your access. The service's matrilineal and patrilineal line testing can geolocate your DNA ancestry in more than 1,000 regions.
Three of the companies, MyHeritage, Ancestry and FTDNA, use the Illumina OmniExpress chip and 23andMe uses the new Infinium® Global Screening Array chip from Illumina. The fact that all of the chips come from the same company may be confusing, leading some to believe that all tests are created equal. This is not the case. The chip used to process DNA samples is only one part of the process. Each company develops their own analysis of the results, references different population samples and provides different reports. In addition, each one of these DNA test providers offers different tools for you to analyze the data you receive, creating variations in results, accessibility and usefulness.
Written out the base pairs in DNA make a sequence, e.g. A T A T C G C G T A A T G C. More than 99.9% of those bases are the same in all people. The order, or sequence, of the letters determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.