Turi is a scientist, presenter, speaker and author who is passionate about communicating science to the public. She\u2019s been working in the field of genetic genealogy since 2000 and is perhaps best known for leading the genetic analysis for the identification of King Richard III<\/a>.<\/p>\n DNA<\/a> sequencing technologies have really moved on in the last 20 years. Now you can sequence entire genomes. For the medical side of things, we know a lot about genes that are involved in particular diseases, and we can tell people whether or not they have a gene that predisposes them toward something.<\/p>\n I got involved in the family history side of things by accident. My PhD was on the link between a surname and a Y chromosome. Surnames, like Y chromosomes, come down through the male line. So are all men with the same surname related to each other? Do they all have the same Y chromosome type?<\/p>\n Back then the technology was based on DNA fingerprinting. We could do genetic genealogy where we could take two people with the same surname who couldn\u2019t find the genealogical links between them. We could take a look at their Y chromosomes and see if they\u2019re related.<\/p>\n Now it\u2019s moved on and there are direct-to-consumer testing companies. So, if somebody comes to us and says, \u201cI don\u2019t know who my biological father is,\u201d we can get their DNA tested by one of these direct-to-consumer testing companies. They don\u2019t sequence your entire genome; they look at tiny differences, about 700,000 of them, which are places on the genome where we know people tend to differ.<\/p>\n We can then upload their DNA to various databases around the world and look for DNA sharing, which we measure with a unit known as a \u2018centimorgan\u2019. You share half of your DNA with your parents and about half with your siblings and about a quarter with aunts and uncles. So, if somebody doesn\u2019t know who their father is, but knows who their mum is, you start to look for genetic matches that aren\u2019t from the mother\u2019s side. From that, you can start to build these family trees.<\/p>\n So this DNA sequencing technology \u2013 this ability to look at huge amounts of DNA all in one go, and look at these genetic measurements \u2013 has absolutely changed genealogical research over the last 20 years.<\/p>\n Read more about genetics:<\/strong><\/p>\n In terms of health stuff, I always say you should go to your GP, ideally. It\u2019s not that the tests are unreliable, it\u2019s just that they might not be looking at all of the genetic mutations that are involved in something. They also don\u2019t give you the care and counselling that goes with that.<\/p>\n For ancestry, I always say take them with a pinch of salt. What the genetic companies do is test of all those little differences. They use a computer to cut your DNA into chunks and it goes, \u201cRight, where\u2019s the closest match for this chunk?\u201d Maybe for that chunk it\u2019s Japan. It\u2019ll do that for all the bits of your DNA that it\u2019s got and do it multiple times to give you a kind of average. It\u2019ll go, \u201cThis is where your matches are, in this part of the world.\u201d<\/p>\n But it all depends on who\u2019s in the databases that the company has. You\u2019ll get differences if you go to another company because different companies have different databases. It shouldn\u2019t be too wildly out, but you\u2019ll get differences.<\/p>\n But in terms of building family trees, it\u2019s fantastic. It doesn\u2019t tell you precisely how somebody is related \u2013 it\u2019s too difficult to, based on just 200 centimorgans. But those companies are actually really good because they\u2019ll say, \u201cYou share 200 centimorgans, so there\u2019s X per cent chance that this person is a second cousin.\u201d And then you have to use the genealogy to work out how that person is related to you.<\/p>\n It\u2019s only in the last decade or so that it\u2019s really taken off and it\u2019s extraordinary what you can do with it. In the first episode of this series of DNA Family Secrets<\/em>, we follow Janet\u2019s story. Her parents have passed away now, but when Janet was young she overheard a rumour one night when they had friends around. A guest said, \u201cSo what\u2019s this about you having had a daughter in Austria during the war?\u201d<\/p>\n Apparently the guests were rapidly shooed out after this. But Janet\u2019s always wondered if she has a half-sister somewhere. So we had her DNA tested by the testing companies and I uploaded the data to various databases. I got a match on one of them. Within seconds, I was in contact with Janet\u2019s half-sister\u2019s daughter.<\/p>\n Then we have somebody like Jackie [in the second episode]. He\u2019s a Holocaust survivor and was brought to the UK as one of the Windermere children. Looking for relatives of people who were part of the Holocaust is difficult because so many people were killed. Ordinarily, when you upload somebody\u2019s DNA to one of these databases, you get matches \u2013 second, third, fourth cousins, even closer than that. With Jackie, we\u2019re weren\u2019t getting them because so many people were killed.<\/p>\n Then I had a breakthrough because these testing companies don\u2019t just look for the matches in terms of you sharing 200 centimorgans; they tell you how large a chunk of DNA you share with somebody. So you get half of your DNA from each of your parents and it comes in quite big chunks of chromosomes. When that DNA is passed down through the generations, those chunks break up into smaller chunks. So the more closely related you are, the bigger the chunks of DNA you share.<\/p>\n I found somebody who shared quite a large chunk of DNA with Jackie, which meant I could start to home in on that family and trace relatives. I can\u2019t tell you the excitement when you think you might have found a relative. You go, \u201cOh my goodness, is she still alive? Has she got kids?\u201d There\u2019s a real excitement in being able to answer these questions for people. And that\u2019s part of the DNA technology nowadays.<\/p>\n So we\u2019ve got 23 pairs of chromosomes and pairs 1 to 22 are our autosomes. One half of each pair comes from mum and the other comes from dad and our 22 autosomes are the same between men and women. Pair 23 is the interesting one as it\u2019s sex-determining. Girls have two copies of the X chromosome, one from mum and one from dad. Boys have an X chromosome and a Y chromosome. We also have another piece of DNA known as mitochondrial DNA, and that\u2019s a small circular piece of DNA that\u2019s in the egg.<\/p>\n Autosomes get shuffled with every generation. So when you\u2019re looking at ancestry, it only takes you back a few generations because it\u2019s such a mixture of our ancestors. But mitochondrial DNA just comes down through the female line so you can trace it back from mother to grandmother to great grandmother all the way back through time.<\/p>\n It\u2019s the same with Y chromosomes, you can do that on the male line all the way back and it\u2019s because they don\u2019t recombine, they just get passed down through the generations. They get little, tiny mutations, but we know how those work. So you can go, \u201cOkay, well, this is a Y chromosome type that you tend to find in this part of the world.\u201d<\/p>\n The databases are growing like mad. So from when we did the first series to the second series, something like over four million people had their genes tested. I think people are moving more and more towards having their entire genomes tested \u2013 people are interested in that kind of thing. And it\u2019s probably to do with issues relating to health. That\u2019s certainly the way things are moving.<\/p>\n So I think it\u2019s going to be the case that these databases are going to be absolutely huge and more and more people will get their entire genomes tested.<\/p>\n Read more about DNA testing:<\/strong><\/p>\n By Sara Rigby Published: Wednesday, 11 May 2022 at 12:00 am All sorts of mysteries lurk in our family trees, from long-lost relatives to adoptees\u2019 hidden heritages. In the new series of DNA Family Secrets, geneticist Prof Turi King sets out to solve them with the help of presenter Stacey Dooley and home genetic testing […]<\/p>\n","protected":false},"author":24,"featured_media":13002,"template":"","categories":[1],"acf":{"readingTimeMinutes":"8"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2022\/05\/the-dna-detective-how-to-solve-family-mysteries-with-ancestry-testing.jpg",1200,511,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2022\/05\/the-dna-detective-how-to-solve-family-mysteries-with-ancestry-testing-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2022\/05\/the-dna-detective-how-to-solve-family-mysteries-with-ancestry-testing-300x128.jpg",300,128,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2022\/05\/the-dna-detective-how-to-solve-family-mysteries-with-ancestry-testing-768x327.jpg",768,327,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2022\/05\/the-dna-detective-how-to-solve-family-mysteries-with-ancestry-testing-1024x436.jpg",800,341,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2022\/05\/the-dna-detective-how-to-solve-family-mysteries-with-ancestry-testing.jpg",1200,511,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2022\/05\/the-dna-detective-how-to-solve-family-mysteries-with-ancestry-testing.jpg",1200,511,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"By Sara Rigby Published: Wednesday, 11 May 2022 at 12:00 am All sorts of mysteries lurk in our family trees, from long-lost relatives to adoptees\u2019 hidden heritages. In the new series of DNA Family Secrets, geneticist Prof Turi King sets out to solve them with the help of presenter Stacey Dooley and home genetic testing…","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/rss_feed\/13001"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/media\/13002"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/media?parent=13001"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/categories?post=13001"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Tell us about the genetic technologies you use in DNA Family Secrets<\/em>.<\/h4>\n
How accurate and reliable are these consumer DNA testing kits?<\/h4>\n
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<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>You mentioned earlier that the Y chromosome is very powerful in tracking ancestry, but why the Y chromosome and not the X chromosome?<\/h4>\n
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<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>Where do you see the future of this sort of DNA testing going?<\/h4>\n
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