DNA testing: pitfalls, bombshells and mysteries solved

The privacy concerns over DNA testing are very real, but for people determined to solve a family mystery, DNA can be a powerful and fascinating tool – if you are prepared for bombshells lurking in your genes, writes Lynn Grieveson.  

The message was from a bemused Portuguese academic. Since no one he knew of in his family tree came from outside the Iberian Peninsula he was curious to know why my father (born and bred in the north of England with no Portuguese heritage) was listed as someone with whom he shared a not-insignificant amount of DNA.

I messaged back via the DNA testing site that my fourth-great-grandfather fought in the Napoleonic Wars – and his Durham regiment was based in Portugal. Clearly he left a DNA footprint there in the form of a child before returning to his wife and life in England.

Would I do it now in the light of evidence of the increasingly sociopathic nature of large tech companies? Possibly not.

But that was just an interesting sidebar to my use of DNA testing sites.

Emma Espiner writes in Newsroom this week that “the inane ‘share everything’ culture has gone to another level” with DNA testing sites offering imperfect science and asking users to sign away control of their data.  

An ‘early adopter’ of DNA testing, I submitted DNA tests for myself, a relative in the UK and my parents with some fascinating results.

But would I do it now in the light of evidence of the increasingly sociopathic nature of large tech companies? Possibly not.

Several years back when I turned to DNA to solve a family mystery, I decided I would not submit tests for my then-teenage children, citing even then vague unease about how such data might end up being used over their lifetimes.

But I cannot regret the decision to test myself and elderly relatives, given the outcomes. If you are serious about researching family history or solving a family mystery, there are good reasons to use the DNA testing sites – especially now so many people are sharing their results on sites such as Ancestry, which claims to have over 10 million tested members.

However, even setting aside the concerns over giving away control of such uniquely personal and powerful data as raised by Espiner, there are good reasons not to jump into it lightly.  

There are potential bombshells lurking in your DNA.

Finding Grandad's secret, losing Grandad

My mother and her sister grew up in the north of England with their cousin Ted. He was fascinated by family history and in the years before the internet painstakingly researched his ancestors using town hall, church and library resources and the records office. But to his frustration (and that of at least one other cousin also trying to solve the mystery) he could get no further back than his maternal grandfather, for whom there were no records prior to his marriage.

The release of the 1911 census in 2011 provided a breakthrough when their grandfather was found living under another name just before his marriage – but even that ended up in even more frustration when that name proved to be backed up by no records as well.

Ted and my mother were not first cousins after all.

The fact that no one knew who his grandfather really was – or whether the family name really was the family name - nagged at Ted for decades. When I started researching the family tree I came across plaintive messages around the internet from him and others asking for any information on the man. Eventually I offered to try to use DNA to solve it.

Testing both Ted and my mother was supposed to simplify the task, since we could narrow down relatives they had in common because they shared that one set of grandparents. But, after many wasted hours, someone with a lot more practice at finding people through DNA took a look at the results and pointed out what I had missed.

Ted and my mother were not first cousins after all.

They shared enough DNA to be half-first cousins, but their grandmother must have had at least one child by someone other than her husband. Ironically, this made the task easier as clues we had ruled out came back into play.

Amongst Ted’s DNA matches we found an Australian close relative whose Danish great-grandfather had changed his surname to that used by Ted’s grandfather before his marriage.

Working on this lead, we finally established that Ted’s grandad was the illegitimate son of this Danish sailor who had jumped ship in Newcastle.

The mystery of why Ted (but not my mother) had so much Danish DNA was solved as a result as well.

Through family trees uploaded on Ancestry he was able to see photographs of cousins he never knew existed, plus one still living that has offered to take him to where their great-grandfather is buried and share family stories.

Beware the unexploded ordinance

The satisfaction of being able to finally answer Ted’s questions about his family was tempered somewhat by the knowledge that I had rendered my mother and her sister grandfather-less in the process. But an extremely close DNA match at Ancestry with a great-uncle who had lived nearby at the time their father was conceived quickly provided an answer to that as well, later backed up by further DNA matches sharing ancestors from the same line.

The DNA test that you take may result in a close relative being told they fathered a child decades ago of whom they had no knowledge.

That unexploded bomb hiding in our family tree caused little damage and a fair bit of amusement.

But people are taking (or gifting to family members) DNA tests and discovering that their siblings are not full siblings, that their father is not their biological father or that they are adopted.

Other people who already know they are adopted are using DNA to track down their birth families. Facebook “DNA detective” groups exist to help them.

So the DNA test that you take may result in a close relative being told they fathered a child decades ago of whom they had no knowledge.

Whether you see this as a positive or a pitfall is something that needs to be thought through before spitting in a tube.

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