Peter Moore: How DNA testing is redefining identity, family, and medicine

I’ve been living a myth my whole life. My great-grandfather was from Ireland, and my grandfather was born in Dublin. I was always proud of my Irish roots. I have now had my DNA checked. It turns out I am only 4 per cent Irish, but 20 per cent Scottish.

My great-grandfather was a Protestant priest, and so it is likely that his ancestors came from Scotland. Should I now support the DUP? 80% of me says no. The good news is that I am 68% Devon, Cornwall, and Dorset. I’ll ignore Cornwall and Dorset and argue that Torquay United is in my DNA. 

Now that DNA analysis can show true ancestry, will this create problems? Will it turn out that someone’s “father” is not really their father? Is there another explanation for my Scottish roots? Perhaps my great-grandmother, the wife of an Irish Protestant priest, had an affair with a Scotsman? 

When I worked in the baby unit in Plymouth, I was warned that some babies were “medically premature but socially term”. When a clearly premature baby was born but “Dad” had been at sea for nine months, we never challenged the mum. Even if the mum insisted the baby was term, we nodded and treated the baby as premature. 

In one case a pregnant mum was readmitted several times as the pregnancy was far too small. Recurrent scans showed a healthy baby growing well but not as far on as she claimed. When she said that she knew she was nearly due, my fatherly consultant put his arm around her and said, “Don’t worry. We get a lot of this in Plymouth”. Today he might be accused of assault, but eventually she delivered a healthy baby, although I do not know how she explained the late delivery to the “Dad”. Let’s hope that when the baby grows up, he does not check his DNA.

In ITV’s “DNA journey,” the actor John Sims found out that his “father” was not his biological father. It turned out that his biological father lived nearby and drank in the same pub. Sadly, he has now died, but John Sims did meet his half-sister. 

The Archbishop of Canterbury, Justin Welby, also had a surprise, and not just because he had to resign. His mother served as personal secretary to Winston Churchill. His “father,” Gavin, was less successful. Both his “parents” developed an alcohol problem and divorced when he was three. Gavin died in 1977 from alcohol-related causes. His mother had stopped drinking in 1968 and successfully remarried in 1975. 

Someone contacted him whose father, Sir. Anthony Montague Brown, a top civil servant, had worked with his mother. He believed that he looked similar to the archbishop. To the archbishop’s credit, he did not dismiss the letter but checked his DNA. It turned out that for sixty years the archbishop’s “father” was not his father. Archbishop Welby had a very successful career as an oil executive before entering the church. His success was probably due to his mother and his real father. 

Although DNA testing is new, the problem of paternity is not. In ancient Rome, any baby born within two years of a soldier going away would be deemed his child. Clearly the gestation period in Ancient Rome was longer than today.

DNA analysis can do far more than look at paternity. Between 1990 and 2003, scientists around the world worked together on the human genome project and mapped the whole human genome, a complete map of human genes and their DNA. It was an amazing piece of research, but now with modern technology, the entire genome can be mapped in five hours. 

By looking at the entire genome, or genetic code, from different patients, we are beginning to work out which genes are responsible for which disease. In a new study, the NHS plans to analyse the entire genome of up to 100,000 newborn babies. This could predict over 200 rare diseases, allowing them to be treated early. 

In the future, DNA analysis will do far more than find out whether I really am a Devonian.