Is it possible for you to get different ethnicity results if you take the test again?

[Intevel]

I'm just curious. I read that you can different results than a sibling. Now I'm curious if you take the test, if it's possible to get slightly different results if you take the test, say 10 years later. I don't understand DNA, but if your genes change overtime, can't your test results change? Like for instance, it might say you're 11 percent Irish. Then maybe 10 years later, could you drop down to 7 percent Irish and become more of something else?

Another reason I suspect this is because I read that you can get different results if you take the test from different sites. So something is up. I'm not sure if I fully trust the tech.

[spruithean]

It has nothing to do with the technology. It has to do with reference populations and comparing someone's genetics to these reference populations. Some of these populations (notably Europeans) are so similar across the board that your results can reflect these similarities (British and Irish, British and Danish, etc).

Your siblings generally have inherited different genes here and there, hence why you share only a certain amount of cM with them. I'm not sure what you mean by DNA changing as you get older...

[Germanica]

I'm just curious. I read that you can different results than a sibling. Now I'm curious if you take the test, if it's possible to get slightly different results if you take the test, say 10 years later. I don't understand DNA, but if your genes change overtime, can't your test results change? Like for instance, it might say you're 11 percent Irish. Then maybe 10 years later, could you drop down to 7 percent Irish and become more of something else?

You can get different results from the same company if there's a long gap in between taking them. They don't use your full genome, only a portion of it. When they process your DNA at the lab, there's a "chip" that extracts the particular portions they want, the portions they know are most relevant to genealogy and ethnicity. Periodically (every few years, or more), there are chip updates which means the portions they extract from your DNA change with each chip. New portions are add, other portions can be dropped. This could influence your ethnicity results somewhat, but probably not too drastically.

Companies also update their sample groups and analyses methods periodically too, and that can influence the outcome of your ethnicity results, however, normally when they do this, they apply it to all previous tests too, so you would not need to test again to see these changes.

Another reason I suspect this is because I read that you can get different results if you take the test from different sites. So something is up. I'm not sure if I fully trust the tech.

Different companies use different chips, sample groups, and analyses, so you will usually get different results at different companies, but that doesn't mean you will get different results by testing at the same company, not unless there's been a drastic chip update.

[Intevel]

You can get different results from the same company if there's a long gap in between taking them. They don't use your full genome, only a portion of it. When they process your DNA at the lab, there's a "chip" that extracts the particular portions they want, the portions they know are most relevant to genealogy and ethnicity. Periodically (every few years, or more), there are chip updates which means the portions they extract from your DNA change with each chip. New portions are add, other portions can be dropped. This could influence your ethnicity results somewhat, but probably not too drastically.

Companies also update their sample groups and analyses methods periodically too, and that can influence the outcome of your ethnicity results, however, normally when they do this, they apply it to all previous tests too, so you would not need to test again to see these changes.



Different companies use different chips, sample groups, and analyses, so you will usually get different results at different companies, but that doesn't mean you will get different results by testing at the same company, not unless there's been a drastic chip update.

So then that means that these results aren't 100 percent infallible?

[Intevel]

I'm not sure what you mean by DNA changing as you get older...

Well could it say you're a quarter black and then 10 years later it says you're 10 percent black?

[Jim Barrett]

Well could it say you're a quarter black and then 10 years later it says you're 10 percent black?

Of course not. DNA testing is changing every day. Cars have changed, airplanes have changed, radios have change and DNA testing is changing. We can test more STRs today, more SNPs, more mtDNA, the Haplotree is growing and ethnicity prediction is changing.

I have never seen a prediction of any % black!

[Germanica]

So then that means that these results aren't 100 percent infallible?

They are fairly accurate on a continental level (ie, European versus Sub-Saharan African) but on a sub-continental level, there is too much shared DNA among neighboring regions to be totally accurate. You definitely shouldn't take them literally.