I am a fan of DNA testing. I find it fascinating and interesting to find out the things we learn from it. However, as much as it adds to my genealogical research, it is not a replacement for it. That is the key bit of information for those who are still considering if they want to test or not. Testing your DNA can help you, but you will still spend hours researching trees.
So what are the advantages? What are the Pitfalls?
1. DNA matches can lead to discoveries on your dead end ancestors, but generally only within the first 5 generations, with the odds decreasing for every successive generation.
the pitfall, you have to be able to triangulate for these type of discoveries, which makes the ancestryDNA matches useless if you can't convince the matches to use gedmatch or the free ftdna transfer.
2. You may find relatives you never knew you had. Personally, I think this is an advantage, but I am not someone who was adopted and never knew it, like a recent second cousin tester just found out. Mostly for me it's been being able to help others who have a question, they are adopted, they don't know who their father is, that even with just ancestryDNA and solid genealogical research we have found the answers for.
the pitfall, you may find information you would rather not know, and to help someone else, it's still a long road of research.
3. If you triangulate, you can find some interesting information. That's the part I love, seeing how some family DNA has been passed down more than others. Seeing the amazing way in which we become who we are.
the pitfall, you can only triangulate with 23andme, ftdna and gedmatch And, it is sometimes hard to get responses from matches.
These are pitfalls only.
1. less than 5% - 10% of your matches on average will have a tree, and if your lucky, about 25% of those you contact will answer your message.
2. Ancestry trees are riddled with errors. While I don't recommend using shared matches and trees as a way to identify a match alone in general, larger matches (above 75 cM) can be identified however, it means really doing the research on your own to verify the match and trees are compatible.
3. Matches that are below 30 cM can be helpful only with triangulation, and only if they can illuminate a larger match or have multiple matches that can point you in a direction.
Monday, May 21, 2018
Don't let the internet DNA scare tactics scare you
There are multiple articles and even news stories on how taking your DNA test is a bad idea. Not only do I not believe that, but I want to be blunt about it. The anti-DNA camp is using scare tactics that the general public will readily believe because they don't know better.
Just this week with the help of DNA and genealogy research I was able to identify the birth father's family for three different individuals. With the thousands of people who are trying to find answers, DNA is definitely useful, and scare tactics just may drive testers away that can be vital for those who are searching.
So what about DNA and what you can or cannot learn from it about another tester.
1. Someone who matches me can tell if I carry a specific gene for a disease. Mostly FALSE.
DNA matches are only for 1/2 of the chromosome. So even if someone knew that for example 1377 CT a genetic SNP variant dealing with metabolism of folic acid was located on Chromosome 14, and they knew the exact location in correlation with the DNA match, they only know 1/2 of the result for the comparison, and only if they already looked at their raw data and knew what their result was and had identified if it was a paternal or maternal match.
Because without testing at least one parent, a tester with raw data who does research their snp's for genetic markers will not know which side they inherited the marker from unless both parents contributed the same marker. Since abnormal markers only need one variant to be positive for a marker, it is possible if they had tested at least one parent, identified the match to the parent with the variant, and then took the exhaustive step of computing the match on that chromosome was in that exact location that they could identify you had an abnormal SNP.
So let's get this straight. To even remotely identify that a genetic match carries an abnormal health gene you need to meet all of the following.
1. know the exact location of the SNP on the chromosome
2. Identify the genetic contributor from your sample (maternal or paternal) by testing a parent and comparing the raw data files for that location.
3. Successfully identify the match to a paternal or maternal match in the exact location.
4. the match has to be to the abnormal variant in that exact location, if it is normal it tells you nothing.
Yeah, I can just see that happens a lot. Most people who test don't even know the basics on autosomal DNA, much less the complex science behind genetics.
2. Test companies sell DNA to 3rd market researchers. TRUE, but...
they also remove any personal identifying information from the data, and require your consent when you test. What this means is that the genetic code, the G,T,A, or C is intact but your name isn't anywhere on it. So while it helps research genes, it does not identify you in anyway whatsoever.
3. Police can use your DNA to help find criminals TRUE, but..
Ancestry, 23andme, and FamilytreeDNA do not voluntarily contribute to police. If I am not mistaken, it specifically says they will only do so if they are given a subpoena or warrant for the information.
About the Gedmatch news story.
Gedmatch is voluntary, and it is free. What is so amazing about the recent news about the serial killer who was found based on DNA evidence using Gedmatch is the improbability of it working in the first place.
Read any message board or group dealing with DNA and genealogy and you will hear the same complaints. A significantly small percentage of tests have a gedcom or family tree attached. I think I have about 50 for gedmatch with over 3000 matches (I haven't looked in a while) for my father and my mother each. So roughly less than 5 % of users even have a tree, and my personal response rate for correspondence is around only 25 % across the board for 4 companies where I have DNA results. Add to that the folks who have tested with new chips have had difficulty because the data is incompatible with gedmatch, it is mind boggling that they took a DNA sample and gave it the right format to be of any use.
Personally, I don't mind if a serial killer is found because my DNA helped, but to each his own.
4. Your giving away your most private information. TRUE, but..
you retain ownership of your DNA and can remove it at any time. Other users (matches) cannot see your raw data, and even if they identify matches, they only know 1/2 of your DNA, they do not know all of it. AncestryDNA allows no comparisons, so if your worried about someone figuring something out that they shouldn't (which I hope I already proven is really, really time consuming and hard), you don't have to worry about it at all. Though to be honest, the biggest pitfall of ancestryDNA is that relying on matches and trees alone is a disaster waiting to happen. Except for close matches, the capacity for errors and assumptions is really high leading to misinformation.
Comparing your DNA and seeing the results does give some information, but even among those who do test for health reasons, they may ask you if you carry a specific genetic marker, but most are not literate enough in DNA to even begin to do the exhaustive study I eluded to in my first point.
5. Insurers can use your DNA against you. TRUE, but..
they do not have access to your actual results. And if we are smart we will ensure legislation keeps that from happening. What they can ask is if you have taken a DNA test for genetic reasons and if you know you are a carrier for a specific problem. That is not all that different from preexisting conditions we are subject to now, except, for many markers, the increased likelihood of disease is only slightly increased. Which is why I am not necessarily a fan of the health DNA market in the first place. It is easy to scare people into believing they are at risk, and often when you read the actual research, the risk is not much higher. I believe before you test, you really need to understand the whole picture, and having a marker doesn't always mean you have the disease.
6. You may find out information you don't want to know TRUE
The biggest risk with DNA is you may find out your father isn't your father, or your were adopted, or one of your parents or grandparents had an affair and had a child. That is a big risk, and if you really don't want to know those answers, then you shouldn't test.
Personally I think the rewards of testing far outweigh the cons, and I hope that now you do too.
Just this week with the help of DNA and genealogy research I was able to identify the birth father's family for three different individuals. With the thousands of people who are trying to find answers, DNA is definitely useful, and scare tactics just may drive testers away that can be vital for those who are searching.
So what about DNA and what you can or cannot learn from it about another tester.
1. Someone who matches me can tell if I carry a specific gene for a disease. Mostly FALSE.
DNA matches are only for 1/2 of the chromosome. So even if someone knew that for example 1377 CT a genetic SNP variant dealing with metabolism of folic acid was located on Chromosome 14, and they knew the exact location in correlation with the DNA match, they only know 1/2 of the result for the comparison, and only if they already looked at their raw data and knew what their result was and had identified if it was a paternal or maternal match.
Because without testing at least one parent, a tester with raw data who does research their snp's for genetic markers will not know which side they inherited the marker from unless both parents contributed the same marker. Since abnormal markers only need one variant to be positive for a marker, it is possible if they had tested at least one parent, identified the match to the parent with the variant, and then took the exhaustive step of computing the match on that chromosome was in that exact location that they could identify you had an abnormal SNP.
So let's get this straight. To even remotely identify that a genetic match carries an abnormal health gene you need to meet all of the following.
1. know the exact location of the SNP on the chromosome
2. Identify the genetic contributor from your sample (maternal or paternal) by testing a parent and comparing the raw data files for that location.
3. Successfully identify the match to a paternal or maternal match in the exact location.
4. the match has to be to the abnormal variant in that exact location, if it is normal it tells you nothing.
Yeah, I can just see that happens a lot. Most people who test don't even know the basics on autosomal DNA, much less the complex science behind genetics.
2. Test companies sell DNA to 3rd market researchers. TRUE, but...
they also remove any personal identifying information from the data, and require your consent when you test. What this means is that the genetic code, the G,T,A, or C is intact but your name isn't anywhere on it. So while it helps research genes, it does not identify you in anyway whatsoever.
3. Police can use your DNA to help find criminals TRUE, but..
Ancestry, 23andme, and FamilytreeDNA do not voluntarily contribute to police. If I am not mistaken, it specifically says they will only do so if they are given a subpoena or warrant for the information.
About the Gedmatch news story.
Gedmatch is voluntary, and it is free. What is so amazing about the recent news about the serial killer who was found based on DNA evidence using Gedmatch is the improbability of it working in the first place.
Read any message board or group dealing with DNA and genealogy and you will hear the same complaints. A significantly small percentage of tests have a gedcom or family tree attached. I think I have about 50 for gedmatch with over 3000 matches (I haven't looked in a while) for my father and my mother each. So roughly less than 5 % of users even have a tree, and my personal response rate for correspondence is around only 25 % across the board for 4 companies where I have DNA results. Add to that the folks who have tested with new chips have had difficulty because the data is incompatible with gedmatch, it is mind boggling that they took a DNA sample and gave it the right format to be of any use.
Personally, I don't mind if a serial killer is found because my DNA helped, but to each his own.
4. Your giving away your most private information. TRUE, but..
you retain ownership of your DNA and can remove it at any time. Other users (matches) cannot see your raw data, and even if they identify matches, they only know 1/2 of your DNA, they do not know all of it. AncestryDNA allows no comparisons, so if your worried about someone figuring something out that they shouldn't (which I hope I already proven is really, really time consuming and hard), you don't have to worry about it at all. Though to be honest, the biggest pitfall of ancestryDNA is that relying on matches and trees alone is a disaster waiting to happen. Except for close matches, the capacity for errors and assumptions is really high leading to misinformation.
Comparing your DNA and seeing the results does give some information, but even among those who do test for health reasons, they may ask you if you carry a specific genetic marker, but most are not literate enough in DNA to even begin to do the exhaustive study I eluded to in my first point.
5. Insurers can use your DNA against you. TRUE, but..
they do not have access to your actual results. And if we are smart we will ensure legislation keeps that from happening. What they can ask is if you have taken a DNA test for genetic reasons and if you know you are a carrier for a specific problem. That is not all that different from preexisting conditions we are subject to now, except, for many markers, the increased likelihood of disease is only slightly increased. Which is why I am not necessarily a fan of the health DNA market in the first place. It is easy to scare people into believing they are at risk, and often when you read the actual research, the risk is not much higher. I believe before you test, you really need to understand the whole picture, and having a marker doesn't always mean you have the disease.
6. You may find out information you don't want to know TRUE
The biggest risk with DNA is you may find out your father isn't your father, or your were adopted, or one of your parents or grandparents had an affair and had a child. That is a big risk, and if you really don't want to know those answers, then you shouldn't test.
Personally I think the rewards of testing far outweigh the cons, and I hope that now you do too.
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