A few decades ago, people might have looked at you funny if you asked them to publicly share the intimate details of their personal lives—where they live, their age, what they had for dinner a few nights ago, photos of their children and more. However, between Facebook, Google, LinkedIn and the rest, it’s almost a trivial matter to find out people’s private details today. And soon, a new study suggests, your entire genome could get added to that list of personal information so easily found online—whether you want it or not.
“The issue is the current status of privacy,” says Yaniv Erlich, a geneticist at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, who led the research. “We need [sponsors of genomic studies] to be respectful to participants, to tell them the truth: that someone can identify you.”
To lift the mask off of genomic data that had been seemingly stripped of identifying information, Erlich and his team focused on the Y-chromosome, typically passed along with surnames from fathers to sons. Genetic ancestry services such as FamilyTreeDNA and Ancestry.com allow customers to trace their paternal genealogy through an analysis of a series of genetic markers known as short tandem repeats on the Y-chromosome (Y-STRs). As a free service, many of these companies also share their large databases of Y-STRs, with accompanying surnames and built-in search engines, to the public. Since demographic information, including year of birth and state of residency, are often included in published scientific reports, and can also be linked to surname records on sites such as such as PeopleFinders.com or USApeople-search.com, it proved relatively straightforward for Erlich and his colleagues to narrow the identity of DNA contributors down to small lists of likely suspects.
As an example, they tested their procedure on 10 ‘anonymous’ personal genomes, taken from the 1000Genomes project and the European Nucleotide Archive. They recovered surnames for half of these men with a high probability of accuracy. After an internet search, they identified not only the individuals to whom the genomes belonged, but their entire family trees. The findings were published today in Science.


