How Accurate are Mail-in DNA Tests?

Mail-in DNA tests have been in the news recently. Test results can be over the map, with even identical twins getting some widely variable results. What's the deal with that?

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John Green -- Executive Producer
Stan Muller -- Director, Producer
Aaron Carroll -- Writer
Mark Olsen – Graphics
Meredith Danko – Social Media

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[oAvalono]

This channel is underrated but desperately needed.

[WPMontgomery]

Mine said “Dude, the only way you could be whiter is if you were Icelandic.”

[Nofxthepirate]

Knowing how inaccurate they can be on ancestry, I'd love to know more about how useful DNA tests are for finding out about health risks/predispositions to certain behaviors etc. Avoiding genetic pitfalls is the main reason I've considered doing something like 23 & me.

[BadgeThunder]

I think he's trying to tell us he's of Eastern European Jewish decent.

[thatjillgirl]

I read a fantastic article once about a woman who took one of these tests and got results she was certain were wrong. She took it again and got the same wrong results. At that point she started to dig into it farther. After a lot of twists and turns, she wound up discovering that her father had accidentally been switched at birth, totally unbeknownst to anyone! So he (and she by extension) had always grown up thinking he had a certain heritage, but in fact he was related to a completely different family.

[Marco_Onyxheart]

But you didn't really answer the question. How accurate are they? We should get a follow-up on how to interpret the data we get back.

[bills-beard]

Oh my God, same. I was so excited to get my ancestry DNA results, only to be told I was almost entirely Eastern European Jewish, which highlighted most of Europe, part of Asia, and the Middle East. Thanks, that really narrowed it down!

[kds]

In our case - we did 23andMe and there were surprises.But having worked in a genomic lab I'm familiar enough with the process. What I do note, as more and more people have their DNA run the results help to refine the data that 23andMe has. It's fascinating.

[andymingni]

I tried 23andme, but they failed to extract any DNA twice and just gave me a refund. Apparently this is a common issue.

[spodvoll]

I had my son's DNA tested via ancestry.com. I had no idea whatsoever whether any relatives had previously done so.
The results matched a few of my cousins, as well as a few of my wife's cousins.

The DNA test was accurate. Period.

The critique in this video pertains to the ethnicity database. Since that's based in statistical probabilities, confidence can never attain 100%. There will always be statistical outliers. And given the sample size....

[FirstnameLastname-zkwf]

People should send in their DNA twice or more times under different names. See if the same company gives the same person different results.

[LowVoltage_FPV]

I'd be interested in a broader sample and the results statistically. Using anecdotal evidence to support or refute the test results wouldn't be in line with the theme of this channel. How many tests of twins come back with large discrepancies? If the results of %90 of the twin tests are very similar, and only %10 is way off, could we not say that there is a margin of error that must be considered?

[MrSlicer]

What about mail in paternity tests? How common are false negatives when parents are a different race? If that even makes a difference.

[productivediscord]

I've been considering getting a dna test to screen for medical issues( I don't care about ancestry) as I'm adopted and can't rely on family history to highlight potential health problems. Does anyone have any experience with medical mail order DNA tests.

[gekkobear]

Lmao I had the exact same results as you. And it's exactly what I was expecting.

[masilomofokeng]

Hi can uou help me to find my generations

[nutiketgotc]

How about a video on why anyone would be stupid enough to volunteer medical PII to an insecure service which isnt covered by HIPPA and outright states that they are going to sell and otherwise misuse your information?

[manolingz]

you are eastern european? i thought carroll is irish.

[gnetkuji]

More concerned about the fact that the companies are allowed to patent whatever they find in your DNA than I am about the test's accuracy. To my mind, the test is just the decoy to get you to give them something they can use.


In any case, hey Aaron, when did your family immigrate to the US? I'm just wondering which political oppression your family was running away from. There was a lot of it, and most of it was from the Tzar, but even if things got better it's not like things were awesome past 1917 either, and *especially* not from '33 to '45, so I'm just curious.

[dlbattle]

Or maybe they're just making it up. So inaccurate it's hard to tell.