DNA testing: are we really who we think we are?
Genealogy and online genetic-profiling are experiencing a popularity boom, but how accurate are these tests and at what cost are we offering up our valuable DNA profiles to databases across the world?
Who are we, really? This is one of the most complex questions any of us will ever wrestle with, and the popularity of genealogy shows how keen people are to come up with an answer. Those wishing to go further than constructing a simple family tree may even choose to send off a small saliva sample to a DNA-testing company on the promise of information about their heritage. “Meet your ancestors’ family,” suggests one Dubai firm. “Trace the migration routes of your paternal and maternal lineages.”
How it works
In recent years, such services have been successfully marketed as an “ideal gift”, and it’s estimated that more than 25 million people across the world have taken the plunge so far. One of the most recent to do so was TV presenter Charlsie Agro, from Canadian national broadcaster CBC.
She and her twin sister submitted DNA samples to five leading companies, but the results – which they assumed would come back identical – showed marked differences. It raised the question of whether the DNA we submit to these companies is more valuable to them than the information they send back to us. The vast majority of our DNA is the same as that of every other human being.
So, rather than sequence entire genomes, the testing companies focus on around one million SNPs, the particular segments of DNA that are known to vary from person to person. By comparing one person’s SNPs to everyone else’s, broad assessments can be made about ancestry – and most customers are perfectly happy with their results.
My father, who recently took one, will proudly tell you that he’s 62 per cent north-west European, 31 per cent Irish and Scottish, 5 per cent Norwegian and 2 per cent Swedish. But it is far from an exact science, and the validity of some rather more specific DNA analyses – for example the location of one’s ancestral village – have been widely questioned.
Understanding the appeal
“Each generation up, the number of ancestors increases, and the spread of where they were born does, too,” says Adam Rutherford in his book A Brief History of Everyone Who Ever Lived. “By 2,000 years ago, they are all over the world.”
His point is echoed in a report produced by the Molecular and Cultural Evolution Lab at University College London, which says, “It’s meaningless to try and pinpoint a single geographical location as the origin of all those diverse ancestors one thousand years ago.”
But these kinds of claims have widespread consumer appeal: personality assessments, relationship to famous historical figures, fitness, diet, love life or even taste in music have all been related to DNA. It may make for good dinner-party conversation, but the UCL scientists are clear: it’s not science. Nevertheless, our fascination with the idea that our genetic code can tell us about ourselves has led to the accumulation of millions of DNA profiles in databases across the globe.
It’s meaningless to try and pinpoint a single geographical location as the origin of all those diverse ancestors one thousand years ago.
The more profiles a database contains, the more valuable it becomes. Markers for various diseases begin to reveal themselves, presenting great opportunities for medical research. Last year, the American DNA company 23andMe announced a partnership with pharmaceutical giant GlaxoSmithKline. Meanwhile in the UAE, the Dubai 10X initiative has announced a plan to create a DNA database to tackle disease caused by genetic disorder (since then, bodies in other countries have followed suit, most recently by the United Kingdom’s National Health Service).
'Is the information itself toxic?'
But there is concern that revealing information to individuals about the medical implications of their DNA test results could cause unnecessary panic. In a recent radio interview, medical geneticist Robert Green raised an important question: “In the sort of genomic journey that our society is on, will patients and providers completely misunderstand the information and do bad things based upon it?” he asked. “Is the information itself toxic?” DNA-testing has also prompted new information to emerge in the field of crime and forensics.
The same mechanism by which our DNA data can be used to track down distant cousins can also be used to identify family members of suspects who have left DNA at a crime scene. The bigger the database, the more chance of finding a match. Last April, a 44-year-old mystery surrounding the murder of 12 people in California was solved when the DNA of the so-called “Golden State Killer” was uploaded to GEDmatch, a huge database created by genealogy enthusiasts pooling their DNA results. A man was arrested and awaits trial.
Since then, more than 30 crimes that were thought to be unsolvable have developed leads using the same technique. Solving crime and preventing disease are good for society, but not all the unintended consequences of DNA-testing are positive. There is concern surrounding who has access to the databases, and the trust we must place in the companies looking after them.
The moral problems that may arise
Back in 2015, one anonymous software developer gave a glimpse of the moral problems posed by open DNA databases when he wrote a script that could bar access to certain websites and apps by 23andMe customers of particular ethnicities. Last year, 23andMe removed the possibility of this kind of abuse by cutting off all access to its data from third party developers – but a database like GEDmatch is open by its very nature.
“Users participating in this site should expect that their information will be shared with other users,” reads its privacy statement. One person’s privacy is also inextricably tied to the privacy of their family. Last October, researchers at Columbia University determined that 60 per cent of people in the United States with European ancestry can now be identified through relatives who have taken voluntary DNA tests. As approximately 80 per cent of all DNA yet analysed comes from white people of European ancestry, the privacy implications are not yet as serious in Asian countries – but it’s a fast-growing sector, with companies such as EasyDNA expanding worldwide.
This whole phenomenon stems for an enthusiasm for discovery, but the information it reveals is not guaranteed to be good news. In the same way that DNA testing can uncover a predisposition towards certain diseases, it can also uncover facts relating to maternity and paternity, which can shatter families. Genetic counselling, once a niche profession, now has a global shortage of people qualified to help those stumbling across distressing news while searching for information about who they are.
The decoding of the mystery of human life is fascinating, and has much potential for social good. But, as with so much developing technology, it raises many questions about our ability to cope with the consequences.
Updated: January 31, 2019 12:51 PM