General Question

gondwanalon's avatar

Do you trust your DNA test results?

Asked by gondwanalon (22879points) June 26th, 2017
26 responses
“Great Question” (3points)

Are you happy with your DNA results? Do they make sense?

Last January “Ancestry by DNA” told me that I’m 86% German, 10% El Salvador Indian and 4% Asian.

I didn’t believe it was true. So I sent a specimen of my DNA to “23andMe” and their report said that my DNA is 100% European (including British & Irish, French & German, Scandinavian).

I’m thinking that “23andMe” report is likely correct but of course I can’t be sure. Looks like I’m going to have to find a third company that tests DNA.

I’m thinking about sending an e-mail to “Ancestry by DNA” and show them my “23andMe” report and ask them to repeat my DNA test with a new specimen (at no additional charge to me).

I worked in a clinical lab for 38 years and I know that anytime that you have people doing anything, mistakes will be made.

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Answers

johnpowell's avatar

“In 2013 the US Food and Drug Administration (FDA) ordered 23andMe to discontinue marketing its personal genome service (PGS), as the company had not obtained the legally required regulatory approval. That resulted in concerns about the potential consequences of customers receiving inaccurate health results.[3] The company continued to sell a personal genome test without health-related results in the United States until October 21, 2015, when it announced that it would be including a revised health component with FDA approval.[4][5] 23andMe has been selling a product with both ancestry and health-related components in Canada since October 2014,[6][7][8] and in the United Kingdom since December 2014.[9]”

So a grain of salt and all.

rojo's avatar

I must admit it was a complete and total surprise to find out I was 19% Scandinavian at least according to Ancestry but I can make the argument that it is a possibility based on where my family comes from.

The thing is it meant my wife is actually more English than I am even though I was born there and the closest connection her family has is to a pair who moved from Scotland around 1820. Everyone else arrived two to three generations earlier and the breeding has been very mixed since that time.

Perhaps I should contact another company.

I know the different companies do not do complete DNA studies (waaaaay tooooo expensive) but select only specific sequences for comparison so that could account for some of the differences if they are looking at different areas of the DNA.

rojo's avatar

My DNA Results from 4 Companies an interesting perspective. Well worth a look. (not sure of the date of this, I think about 2014/2015.

Also from the above Your Genetic Genealogist which concludes that for most 23 & Me is the best at this time.

rojo's avatar

Ancestry’s Mythical Admixture Percentages But this is from 2012 I would think they should have ironed out some of the kinks since then.

ARE_you_kidding_me's avatar

23&me was rightfully handslapped for trying to estimate medical risk from genetics. There is reason to raise caution when bad genes are found but you cannot assign risk they way they did. Ancestry results are an estimate and 23&me gives you several options for speculation. Early on they estimated my “neanderthal %” at 3.2% or 99th percentile. After they changed their web format I’m now like 52nd percentile so very speculative stuff is pretty worthless right now. The ancestry is accurate but granular so if you’re from europe, africa or asia then they’ll be able to tell without question but as you drill down to the finer details it’s harder to distinguish. I like knowing what specific genes I have and the ability to look them up in tbe raw data.

LuckyGuy's avatar

When you submit samples for these tests are they “data blind”. By that I mean no information about the heritage or name of the owner is supplied to the lab. Do you have to fill out a chart that lists your grandparents and other ancestors?

I would like to try one of these tests and then have it repeated on a child to see if the results are consistent. But, for that to be a truly valid test the samples should not have any information attached.

JLeslie's avatar

I would write them. Maybe write both companies.

Mariah's avatar

It certainly seems like one of the companies you got yours through must have made a mistake. I agree there’s room for human error in this testing.

I trust my results. I got 23andme done for free because they were doing a study on IBD and my DNA was valuable to that study. We were very surprised when it came back 30% Ashkenazi Jewish as we weren’t aware of any Jewish blood in our ancestry. We’ve already done quite a bit of genealogy research on my mom’s side, so my dad then got a test done through ancestry.com. Came back 45% Ashkenazi Jewish. Having confirmed it with two different companies I’m convinced it wasn’t a mistake, but we’re amazed to learn that basically one of his parents must have been full-blooded Jewish, because we had no idea. There was plenty of reason to keep that kind of thing secret during that time in history of course. At this point his dad is dead and his mom has dementia so we don’t know if we’ll ever find out the story.

filmfann's avatar

I have lots of experience with the Ancestry tests.
One variable that can mess up these tests is if you have had a bone marrow transplant. Apparently, the DNA from that can really confuse the results.
Another thing many people don’t understand is how siblings can get very different results. This is because you are getting half of your Mother’s, and half of your Father’s DNA. You are not necessarily getting the same halves as your sibs. My sister show much more Jewish, German, and Asian than I did, while I had more Moroccan, Scottish, and Italian (without my double checking the paper). This also accounts for unexpected omissions. My Mom always told us our great grandmother was American Indian, but our tests didn’t detect any.
As far as being tested without giving the company any hints as to my heritage, I have been contacted by several people who did just that, and the company correctly connected them to my family. This has been quite helpful in researching family tree information, and has connected some people who were adopted to their true families.

gondwanalon's avatar

@LuckyGuy I gave these companies no information about me or my ancestors. I have a last name that sounds like it might be Irish. Each of my specimen ID labels had only number bar codes (no name).

JLeslie's avatar

@filmfann Even if a bone marrow transplant can mess up results (I didn’t realize that) the results should still be consistent between the two companies. They are still analyzing whatever your current genetic make-up is.

gondwanalon's avatar

“Ancestry by DNA” changed their name to “HomeDNA”. It still let me log in so I sent them the following note:
************************************
“My DNA was recently tested by 23andMe which generated substantially different results from the results that you obtained from my DNA (86% European, 10% Indigenous American, 4% Asian).

The 23andMe results showed that my DNA is 100% European (broke it down to various percentages of Scandinavian, French, British, German and Irish).

What to you think of this?”

…................Anyway…....................
I never had a bone marrow transplant or even a unit of blood given to me.

jca's avatar

I had mine done by Ancestry.com about a year and a half ago, and then I just recently had it done by 23 and Me. The results were the same and reflected fairly closely what I knew about my ancestry. My father is from Mexico and it did have some Native American, so maybe that’s from indigenous people mingling with Spanish (from Spain, which is where my father’s family was from originally). I’m 3% African. I didn’t have to tell anything about my family before having either test.

jca (36062points)“Great Answer” (4points)
ARE_you_kidding_me's avatar

Another thing to consider is the generation of sequencing hardware they are using and the actual percentage of your genome that was tested. Information about where genes originated is a dynamic science also. All of us are essentially early adopters so we are probably in for a few surprises as the technology improves.

Darth_Algar's avatar

I might be the only person in the world that doesn’t really care about such things. I know my heritage and don’t need a DNA test to tell me that.

gondwanalon's avatar

“HomeDNA” just e-mailed me with the message below in an effort to justify their findings of my DNA. Seems like genetic gobbledygook BS to me.

**************
Good Morning,

I apologize that you are unsatisfied with your results. GPS is based on a new conceptualization of human populations that considers everyone as mixed from different gene pools. This model is fundamentally different from existing approaches, which suggest humans branched from 3 or 4 populations that changed over time. GPS instead relies upon genetic uniqueness due to mixing of global gene pools in different proportions. In addition GPS exploits autosomal DNA (chromosomes 1–22), which have better sensitivity to the genetic signature of one’s most recent common ancestors. GPS Origin uses 36 gene pools to trace the origin of your DNA, more than twice of what is being used by contemporary tools.
 
Regards,
 
Mia

rojo's avatar

@gondwanalon Did you get the opportunity to read the Mythical Admixture Packages article I referenced above? The premise of the guy that wrote it is that their admix percentages are wrong and that is why they get results so different from other testing sometimes. Sounds like that is what Mia is saying as well, we use different starting points that give us different (and we think better) results.

gondwanalon's avatar

@rojo Thank you for that link. I must admit that I did not do well in my college genetics classes. And I’m slow with seeing through such conceptual material. But I think that I’m just starting to get an idea of what is happening. It looks like each company lab analyze different areas of the chromosome that they think that best represents ancestry. So it is possible to get drastically different results. Both reports could be 100% accurate with the portion of the chromosome that they looked at.

rojo's avatar

That’s what I figure @gondwanalon. Kind of like how siblings can have certain segments of DNA that their other siblings don’t or how I can be related to someone who doesn’t show up on my Aunts results even though we know there is a direct connection. Except, I guess this is just luck of the draw while with the testing each company has chosen what they think is important and let the rest slide, so you are right, it might be there just not observed.

LuckyGuy's avatar

This is an excellent discussion. I know things are changing quickly (like the drone market) . but I am still a bit confused as to which one is best.
If I were going to pick one, which would you recommend?

@rojo I checked out the link yo mentioned and noted it was from 2012. That is like 50 years in DNA testing technology time. I wonder if that is still valid today.

jca's avatar

@LuckyGuy: I was happy with the one from Ancestry.com. I got a Cyber-Monday special for $69. I often see similar deals they put out for Father’s Day, Mother’s Day, etc.

jca (36062points)“Great Answer” (2points)
rojo's avatar

@LuckyGuy @LuckyGuy Yeah, I noticed that and mentioned it in the earlier answer. It still appears that Ancestry is doing it differently from the others though, even after five years. Perhaps they just “perfected” their version of reality.

gondwanalon's avatar

@LuckyGuy Whatever you do just have your DNA tested by one lab.

A man with one clock knows the time. A man with two clocks is never quite sure.

Wish that I just accepted the results of my first DMA test results from “Ancestry by DNA (HomeDNA). I was happy thinking that I’m 10% Indigenous American. I’m not sure of anything now.

ARE_you_kidding_me's avatar

IMO the only real information worth getting the test for is to know what specific genes you have. 23&me allows you to download the raw data. It’s been invaluable, I identified a couple mutations using the snmp database through https://promethease.com/
My doc now has me on a baby aspirin because of one. This is only going to get more and more important.

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