I’m Tina Hesman Saey, senior writer covering molecular biology for Science News. I tried 8 different genetic tests to share with you what to expect: AMA!

what are these companies actually telling us — and what are they not telling us?

There is a wide variety of information you can glean from these genetic tests. Some give information about genetic variants that affect your physical appearance: hair and eye color or whether your earlobes are attached or detached, for instance. You might also learn whether you carry variants that put you at higher risk for some diseases, or variants that you could pass along to your children that would lead to a recessive genetic disease (one in which both parents have to pass on a faulty copy of a gene).

For ancestry testing you can learn how much Neanderthal DNA you carry, what continents your ancestors came from and find DNA relatives.

None of the companies tell you everything about what they find in your DNA.

Do they withhold information, or is it just info they figure nobody would care about?

A little bit of both. Sometimes they make the determination that a variant isn't harmful to your health so they don't tell you about it. Sometimes they aren't that confident in the result, so don't report it. Other times, the FDA won't allow companies to report the data they have.

Wait a second. "The FDA won't allow"? What does that mean? Why would the FDA not allow your own test data to be shared with you?

In 2013, the Food and Drug Administration told 23andMe (and by extension other consumer DNA testing companies) that they could no longer offer health information. There were concerns about accuracy and whether consumers would understand the results. Since then, 23andMe has worked with the FDA to get approval to offer some health information. Other companies get around this by requiring a prescription or having a doctor sign off on the testing. For some, that's a formality and they will even provide a doctor. Others require your personal physician to write the order.

Did you resubmit your information to the same testing facility using different user information to look at consistency?

I didn't, but it's a good idea. Someone should try it.

Do you have concerns about privacy with these companies collecting individuals’ most intimate data on a mass scale? Do any of the companies you have tried have policies that concern you more than others?

The companies I tried all had similar privacy and user policies. The thing that is most concerning is that these policies can change after you've agreed to them.

You also have to keep in mind that your DNA is a representation not only of you, but of your relatives, too.

I personally am not overly concerned with sharing my DNA information, but I do sometimes wonder what exactly is happening to my genetic information now.

For more see this excellent piece by Cassie Martin.

The relatives bit is a very important consideration. When we reach that dystopian future, the fact that you took these tests will mean that your grandchildren, and even your great nieces and nephews, have partial DNA profiles on file.

Who owns your DNA privacy is an interesting question because so much of it is shared with our relatives. If they choose to give up their privacy then by association you lose some of yours as well.

Not even necessarily dystopian future. This works in the dystopian present too. Like in the arrest of the Golden State Killer:

Police said they checked the crime scene DNA against one of the genealogy sites that have lately become popular — databases filled with the profiles of people who have volunteered their genetic codes in the hope of discovering their relatives and ancestors.

The suspected Golden State Killer was not in this database, either, but it didn’t matter. A distant relative of his was, police say, and that person’s DNA partially matched evidence related to the serial killer.

source for GSK bit

Obviously I'm glad it led to this guy getting slammed, but it's not so cool when innocent people are implicated in crimes.

[edit:spellfail]

Here's the science behind how the Golden State Killer suspect was caught:

https://www.sciencenews.org/article/golden-state-killer-suspect-dna-genetics-genealogy

A second murder suspect was also caught this way

https://www.sciencenews.org/article/genetic-sleuthing-murder-suspect-cold-case-talbott

And there are plenty of people concerned about what this means for genetic privacy.

https://www.sciencenews.org/article/why-police-using-genetic-geneaology-solve-crimes-poses-problems

https://www.sciencenews.org/blog/science-public/privacy-and-consumer-genetic-testing-dont-always-mix

How accurate are the tests? Which ones are more accurate?

Accuracy depends on what you're testing for. Sometimes there are mistakes in the genetic variants you carry, but more often, the mistakes happen in interpreting genetic data. That's especially true for medical information. Ethnicity estimates are still not very accurate, but DNA relative matching is pretty good.

So in 23&me, you can adjust your % accuracy in the results. So they default in the middle...then you can up the accuracy percentage and they'll adjust their confidence in their %...you don't seem to mention that in the article. Did you play with that feature?

I did. There wasn't space to share all of the things I learned. Living DNA also allows customers to explore several levels of geographic ancestry. And digging deeper into AncestryDNA shows that their confidence rates also vary.

What range of variation did you find between the test results?

The medical test results were fairly consistent, partly because not much of health can be attributed to single genetic variants at this point.

Ethnicity estimates varied fairly widely. The companies agree I'm European and have British ancestry, but their estimates were all over the map. You can read about that here.

Have you heard of the Genes for Good project?

No, I haven't. Tell me about it.

It's a project at the University of Michigan. They test your saliva and send you the raw data: https://genesforgood.sph.umich.edu/.

I did this and used an online program to read the raw file. Then I did the Nat Geo 2 test and was unhappy to learn that they don't return the raw data. I had the pay them extra if I wanted additional information - not raw data but their interpretation of it.
I haven't looked into this - but is it typical to get the raw data back or do the companies give you a little basic info and charge you if you want more?

Most of the companies allow customers to download raw DNA data for free. Some require you to pay for it.

People use third-party analysis services to analyze the DNA. Those services include Promethease and LiveWello and others. There are issues with doing that, that are covered here:

https://www.sciencenews.org/article/health-dna-genetic-testing-disease

Various apps are also available via GenePlaza and you can buy them at places like Amazon, etc.

Helix sequences the exome -- the protein-coding part of your DNA -- but doesn't analyze it. You have to buy apps from its partners. Helix then sends the partner limited information about certain genes or variants and the partner tells you what it means.

I've heard a rumor that genetic testing for people of color is very inaccurate. Mostly due to the fact that they do not have as much data from people of color. In my case, I am of Asian descent, and I read an article somewhere that for Asians especially, the data is pretty low. Is this accurate? Or did I get fed a bunch of lies?

You are correct. Reference populations in Asia, Africa, the Pacific Islands and for Native Americans are not well represented. So you may get less than satisfactory results. You can read about that here https://www.sciencenews.org/article/dna-testing-ancestry-family-tree

How are you?

I'm good? You?

I'm doing well, thanks. Thanks for doing an AMA! We need more AMA's like this, of people who have interesting and important information to share, and fewer celebrities promoting movies. Cheers!

Well, actually... We made a Lego movie that explains DNA recombination for this series. https://www.youtube.com/watch?v=RZWB_xt0chY

Have you already written the article that explains all of this? If not, why are you doing the AMA first?

Admittedly, this is more of a journalism question. I'm assuming here that you've done the research, are now effectively interviewing your potential audience to get an idea of how to write it, then will follow up with the article. Is that the case? If so... kinda brilliant.

I've written a series of articles explaining all of this. But I think most people have not read it. You can find it here:

https://www.sciencenews.org/article/consumer-genetic-testing-ancestry-dna

Are these any companies that said you were “not as risk” for something while another said you were at “high risk?” If so, what can cause these discrepencies?

I didn't encounter this particular situation. What I did find was that when I uploaded raw data to the analysis service Promethease, I found I was at slightly higher risk than average for some diseases that 23andMe didn't tell me about, and that didn't show up in my whole genome analysis from Veritas. What might account for such a discrepancy are errors that are present in raw data. One study found 40 percent of disease risk findings from consumer genetic testing were false positives. Those people thought they had a risk variant for cancer, but it turned out not to be true. Another reason for the discrepancy is that Promethease reports what's in the scientific literature about a variant, but some of that information also turns out to be bad. Clinical testing through a doctor or genetic counselor is the only real way to sort this out.

Are these companies using SNP arrays, or are some of them doing targeted resequencing, or even wgs?

The ancestry testing companies are mostly doing SNP arrays. SNPs are single nucleotide polymorphisms, places in DNA where people naturally vary. Some of those variants change amino acids in proteins, which can change the way the protein works and affect health. Others are just markers that have been loosely associated with disease risk, but aren't causing the problem.

Genos and Helix both do exome sequencing. Helix is exome plus.

Veritas Genetics and others do whole genome sequencing.

I did testing at all those levels and reviewed the experience here. This story tells you what you can expect to learn and lays out the different levels of testing available.

My siblings (37M & 46F) and I (39M) recently took the 23 and Me test. I am the only one that came back with trace amounts (1%) of African American DNA, everything else was identical. The test implied that this trace amount of DNA was from the late 1800's. I'm curious why neither sibling had this DNA or if you think it is probably just a mistake? Thank you!

DNA recombination is going to give you and your siblings a slightly different mix of DNA. Just by chance you happened to inherit the little bit that is African American. According to 23andMe, I inherited from my dad 0.2% of my DNA that is from North Africa or Arabia. Have either of your parents been tested?

This video may help explain it. https://www.youtube.com/watch?v=RZWB_xt0chY

Have you tested their validity by submitting non-human DNA?

I didn't do that, but other reporters have. Most companies could tell it wasn't human DNA, but a few gave results that were concerning.

https://newsinteractives.cbc.ca/longform/dna-ancestry-test

https://www.nbcchicago.com/investigations/home-dna-kits-481292431.html

What are these companies doing with all this data? Do you know what they plan to do?

The companies are doing their own research and collaborating with other scientists on medical research. Some sell the data to pharmaceutical companies. They haven't shared their plans with me.

Did you find any shocking results (health wise)? I feel like I'd rather not know I was prone to a disease to an extent.

I didn't. I have a boring genome. Most relatively healthy adults will also have boring genomes, but that's exactly what you want.

I've talked with many people who feel as you do and don't want to know. I like to be prepared, or at least, I think I do.

Did any of the tests offer metabolomic profiles? Such as p450 enzyme genotypes?

None of these did. They were all straight DNA testing.

Hi Tina.

There are some obvious benefits to understanding and expanding our understanding of DNA. Targeted treatments are one example. Do you see any downsides? Leaving out the popular discussion around designer babies.

Scientifically I don't see downsides, but society has ways of twisting information. For instance, many white supremacist groups use ethnicity testing to promote their agendas.

How much do the results vary, between different companies? Have you seen any indications of how they store/secure the kits and resulting data long-term, or how they might use/sell either in the future?

Companies sometimes update the technology they use for testing. In those cases, you might need to retest to get the newer information. I don't think they hang on to your DNA.

I swear I don't work for 23&me, just have used their services. They send me new results each time they add another genetic test.

They do update information, but they are using data they already collected. If a new report requires data on a SNP that wasn't on the chip they used when you tested, they won't be able to tell you about it.

Do you have a dog or a cat?

Neither. But dog owners can also get their dog's DNA tested from a couple of different companies.

Hello, thank you for your time

Will any of the companies give the patient their complete DNA?

I tested with a company called Veritas Genetics to learn about what's in my whole genome, that is all my DNA. (Well not absolutely all, but close to it.) It costs $999. You can read about my experience with that here.

Other companies will also do whole genome testing, but it costs more.

What is the job outlook for science journalism? How do you become interested in writing science?

Most science journalists are freelancers. There are few staff jobs for writers (although Science News is hiring!)

I got into science journalism on a need-to-know basis. I just need to know about all the cool stuff being discovered. I was a scientist and then I decided what I really liked was learning about science and telling people about it. After I finished my Ph.D. I went to journalism school and did excellent internships at the Dallas Morning News and Science News. I love my job.

So I've been seeing posts and news articles about genes turning on and off (particularly I learned about the gene that allows us to process lactose). Is it possible to manually turn genes off or on? for example the gene that allows us to drink milk, can you go in and turn it back on? I'm not a scientist so I'm not sure how all this works lol.

In all of your cells you have the same DNA. But heart cells and liver cells, for instance, are different because they turn on different genes. Scientists can manipulate gene activity in the lab, but haven't really figured out how to do it in people yet. Maybe one day they will be able to, but for now, you're stuck with lactaid and other enzyme replacements or alternative milk sources.

How long do you think it will take before genetic editing becomes commonplace? What kind of ethical concerns will arise from this? Do you consider yourself more of a scientist or a journalist? What’s the coolest place you’ve gone to? Thanks for your time.

It's already fairly common. More than 7 million people got tested by AncestryDNA last year alone.

Nearly a third of people in a recent poll said they'd considered DNA testing.

I am a journalist. The coolest place I've gone to as a journalist is a lab at Harvard where they are experimenting with resetting people's biological clocks with green lights. It makes the whole world look black and white like you're in an old movie.

Do you think that some of the data collected could go on to power GWAS studies? Any plans from any of these companies to do so? Thanks for the AMA!

Many of these companies do contribute data to GWAS studies. GWAS are genome wide association studies. They use statistical methods to find links between genetic variants and diseases. Most variants nudge disease risk very little, but sometimes you do find big hits, like with certain variants in the breast cancer genes.

Many companies give you the option to contribute your DNA in anonymized form to research studies.

do any companies test for Neanderthal or other non-sapiens DNA?

Thank you for the AMA.

23andMe and National Geographic Geno2.0 both offer Neanderthal testing. Family Tree DNA does some testing of ancient modern humans. I don't think any companies do Denisovan or other non-sapiens testing.

I have to start by saying I'm not taking the piss. How hard was it to sell this as an article? And did anything surprise you?

My editors were enthusiastic and supportive of this project and gave me six months to work on it nearly full time. That's the kind of science journalism Science News is dedicated to.

Which of those tests test for the brca-1 and brca-2 mutations? In my family an abnormal amount of people have had related cancers, younger than average. But most have passed by now, and those who didn't aren't interested in finding out if they are carriers. I'm at least 2 generations removed from those who had the disease, so in my country I'm not elligible to get tested myself, so I want to look into other tests like these to try.

I don't know if you can buy some of the tests available in the United States, such as Color Genomics tests for hereditary cancer. There are lots of reasons people get cancers and genes are only a small part of it.

How can I synthesize one of those pills that improve memory in mice?

Get a job at a pharmaceutical company?

How are the vague and inconclusive results from these expensive ($199 and up) tests more entertaining than going to a psychic $10-50, reading the horoscope (free), or a fortune cookie (meal purchase may be required)?

There is more science involved in DNA testing than the other forms of entertainment you mentioned, but you are right that it's still early days. Genetic testing and interpretation will get better. I don't know that the other will improve their accuracy.