The at-home DNA test craze is putting us all at risk


– I’ve always wanted to take
one of these at home DNA tests ’cause I wanna learn more
about my family’s background and they’re super cheap
so I figured why not? – And I have no interest in these tests. I think it’s really creepy for some company to have my private DNA. Either way at home tests like 23 and Me or Ancestry DNA have
exploded in popularity. By one estimate, around 26 million people have taken one of these tests. – So maybe I should be worried
about my privacy because my DNA is getting uploaded
to some database somewhere. – But here’s the scary
thing, even if I refuse to ever take one of these tests, my DNA could be at risk, too. The reason why starts
with a serial killer. Our colleague Rachel explained it to us. – So the Golden State Killer is also known as the East Area Rapist and in the 1970s and 80s he raped and murdered people across California. – He was wearing some
type of a mask or hood. – [Rachel] And for decades, investigators just had no idea who he was. – Their was some DNA left at crime scenes, but even after decades investigators couldn’t find a suspect so they had nothing to compare the DNA to. But all that changed in 2018. – So the big break through came when investigators
uploaded genetic profile from the crime scene DNA to this big, huge genealogical database. They didn’t find an exact match, but they did find matches to relatives. – [William] Investigators used a method called a long-range familial search to find similarities
between the crime scene DNA and a few of that person’s third cousins. From there they could
narrow their search way down and look for a suspect within a specific family tree and they found one. – The answer was and always
was going to be in the DNA. – [William] Investigators solved the case because of the big DNA database they used which didn’t belong to law enforcement. It’s freely available
and they data inside it came from services like 23 and Me. An at home DNA test like 23 and Me generally works by looking
at spots in your genome called Single Nucleotide
Polymorphisms or SNPs. Each one is a specific location where there are known variations
from person to person. Companies make their
guesses about your ancestry by analyzing thousands
or even millions of SNPs. Populations in Europe,
say, are more likely to have one set of variations, whereas Asian populations
might have a different set. For an end user like Danush
this is the product being sold, a map of his ancestral stomping grounds. – I got 86.7% Western
Asian which on the map is highlighting Turkey, Iran,
Iraq, that part of the world. – But underneath the UI is the raw data. The log of all those SNPs. That data ends up in a private data base owned by whoever sold you the test kit. Now here’s where it gets interesting. Investigators working a case have a few options for
doing a genetic search. First they could search
through a testing company’s private database if they can gain access. Family Tree DNA was in the news recently for actively working with law enforcement. 23 and Me says that it won’t do that, but there’s always the
threat of a court order. So that route is tricky. Second, the FBI does
operate a national DNA index with around 17 million
identified people in it. And some states allow the index to be used for familial searches. But those 17 million people are
all arrestees and offenders. So unless the suspect had relatives in the criminal system it’s not much help. But investigators in the Golden State Killer case found a third option. More and more, customers of DNA services are voluntarily posting
their genetic profiles on free to search websites like GEDmatch, DNA Land, or Family Tree DNA. This is great for anyone doing genealogy or looking
for long lost relatives. With a few clicks on GED Match, you can create an account,
upload your DNA profile, and maybe find a bunch of third cousins you never knew about. But it was also great for investigators tracking the Golden State Killer. – So law enforcement
used it in a similar way. They took the crime scene DNA, created a fake profile and uploaded it, and then looked for relatives. – That was the break through. They used DNA info that
was freely available. No need for subpoenas
or criminal databases, it’s just sitting there, but this is where my privacy is at stake. Let’s go back to that
big web of third cousins. It was used to catch a
serial killer, that’s great. But instead of crime
scene DNA, swap in my DNA. I leave my DNA all over the place. I shed hair, skin cells, saliva, but I’ve never gotten my DNA sequenced. So I shouldn’t have
anything to worry about. But through familial testing,
if enough of my relatives took tests I could be
identified from a DNA sample just like the Golden State Killer was. Now I’m not planning on
committing any crimes, but there are still
privacy concerns for me. First, false positives exist in DNA tests. So I could end up the subject of an investigation by mistake. Or a sketchy insurance
company could find a way to correlate some of my genetic data with other medical information
and discriminate against me. We asked a genetic privacy expert Natalie Ram about these concerns, and she said that the
unifying problem is control. – [Natalie] Your genetic data is a link that you share with family
members involuntarily. It’s not something I’ve chosen, and it’s something I cannot change. – And to up the anty, as databases grow, more and more people will be findable by their hundreds and
hundreds of distant relatives. – [Natalie] And then
you’ve gotta ask, gosh, how many third cousins do I have? Do I even know who all those people are? – A recent study assigned some pretty surprising hard numbers to this. It predicts that for any population that shares some common ancestry, having DNA from just 2% of the people could make anyone findable
via a third cousin or closer. For example, all Americans
with some European ancestry could be matched from just a 2% pool. So if free databases get diverse enough, everyone in America could
be findable via their genes. Which means DNA just won’t
be anonymous anymore. – [Natalie] The bottom line here is that we are rapidly approaching a place where we have a defacto
national DNA database. – For now lots of people
are debating policies that would regulate familial search. One law proposed in
Maryland would completely ban familial DNA searches
of consumer databases. A more extreme policy could create an official nationwide DNA database. That sounds creepy, but it might be easier to regulate than the defacto
system we’re headed for. In the meantime, while we
debate all these questions, piles and piles of at home
DNA test kits are sold. The database continues to grow, and the genetic drag net grows too. Hey so we made this video in
collaboration with vox.com, and Danush has made a companion video that you should check out. – Yeah so our video looks
into how these DNA tests actually work and what they
can and can’t tell you. So make sure to go check that one out. – Yep watch it now, it’ll be
right over there, I think. – Smash that like button.
– Gross.