DNA Testing – Part 1

January 20, 2015 at 10:36 pm | Posted in uncategorized | 3 Comments

One of the more remarkable developments in recent years is personal DNA testing. With new chip technology and for an increasingly reasonable price, we can trace family history, both fathers and mothers lineage, ancestral origins, genetic health markers, and contribute to a growing body of research.

This is of particular value for people unaware of their roots or genetic make-up. But anyone curious about these things will find a fascinating trove of information. However, there are a few caveats. You may discover unexpected ethnic roots or unwanted connections, like unknown links to an “illegitimate” family branch.

The services do give you the option of not accepting connections from genetic relatives who have also tested but that choice tends to happen before you know what sort of connections exist. Here’s an article talking about some of the pros and cons.

Genetic discrimination is another growing issue as testing becomes more common – both personally and for medical reasons. For example, you can have the marker for an illness that never manifests yet it may be used as a reason to deny you insurance.

In my own case, I’d rather be informed and prepared. However, I have little concern over health surprises due to my age and because close family members have already been tested.

There are now both DNA testing sites and post-test sites for further research.

The best known and original testing service is 23andMe. They offered both ancestry and genetic health traits. The US banned health results in 2013, evidently because it was considered “diagnosis”. But this is still available from them for those in the UK and Canada. For ancestry reviews, 23andMe has been suggested to be the most accurate. This would partly be due to their sample size from prior tests.

Another option is FamilyTreeDNA. This is more focused on ancestry, genealogy (cousin matching in the test population) and history. They offer specific tests for the male line (y, only men have), female line (mitocondrial), and the usual autosomal (genetic markers). They’re also available in packages. The other services mentioned have a single package. FTDNA also have a feature to upload your test results from other services, adding to the “worlds largest database”. If you use another service, this gives you more cousin matching and another ethnicity report for comparison. (the more they have, the better the results for everyone)

The big family tree service Ancestry.com now has a DNA service called AncestryDNA, tracing your genealogy and ethnicity. Some features are only available to their subscribers so this choice is best if you already use their services.

And most interesting is the National Geographic Genographic survey. Their focus is human origins or deep ancestry and the kit has been on sale lately. It checks the largest number of genes overall and is inclusive of 4 tests but has the smaller population base so offers less useful recent ancestry data. However, it also tests ethnicities not available elsewhere. One option to support them is to do the test here, then load it onto FamilyTreeDNA above that they partner with.

Not all of the tests are as clear as FamilyTreeDNA for what is included so comparisons can be tricky. Understanding the terminology is another issue. I found this wiki with detailed comparisons quite useful. It gives you a much better sense of the features included in each and their unique offerings.

Each service has background to help understand the reports you get and they vary somewhat by emphasis and what is being tested. The test itself is either a small saliva sample or inside cheek swab. On purchase, they send you the test package. You register on their site and send the easy sample back. Then they notify you when the test results are available in a few weeks. The DNA test data can then be used for further research at other sites.

Some of the post-test services include GED match.  YSearch (for men) has affiliated with FamilyTreeDNA.

To compare your family tree with the genetic results, you need a gedcom file from family tree software. If you don’t have that, you can enter it here to get the file.

If you have British Isles history, this site helps use your DNA’s dominant surname to track place of origin. And many more options.

Here is a web site discussing the available services and research. And a blogger who did all 4 tests and compared them for ancestry data.

Results are based partly on comparisons with prior testers so the more testers, the better. Some parts of the world have a lot less data and so results may be misleading. If this is the case for you, try to get more family members tested.

I’ve ordered the 23andMe kit due to the inclusion of the health markers. I’d like to take advantage of that while it’s available. I’ll write a second part in a few weeks when I have the results.
David