There is a certain occurrence in genetic genealogy called a Non-Paternal or Non Paternity Event. This is a break in the ancestry of a person’s Y chromosome and surname. A person named “Smith,” for instance, might have a Y chromosome that is clearly “Johnson.”
A non paternal event can occur when an adopted male takes the surname of his adoptive family, or a male child takes his step-father’s surname, or a male child takes his mother’s surname (undoubtedly there are other circumstances as well).
When a break in the Y chromosome is suspected or confirmed, it is possible that the break might have occurred 1,000 years ago, 100 years ago, or with the testee’s birth.
An article in The Atlantic titled “Who’s Your Daddy” addresses the ‘unintended consequences of genetic screening for disease.’ Or, in some cases, the unintended consequences of testing for genetic genealogy. The author, Steve Olson, recently underwent genetic genealogy testing:
“A scientific officer at a genetic testing company knew that I was interested in genealogy, and he had offered to run my DNA through a sequencer. A few weeks earlier, I’d swished mouthwash inside my cheeks, sealed the mouthwash in a tube, and mailed the tube to the company.”
The results of Mr. Olson’s (when I say that name out loud, all I can think of is ‘Little House on the Prairie’!) test revealed that his DNA was what he predicted it would be – of Scandinavian descent.
However, as Mr. Olson points out, this doesn’t always happen. The article cites Bennett Greenspan, of Family Tree DNA, as stating that “any project that has more than 20 or 30 people in it is likely to have an oops in it.” This aligns well with the traditional belief that anywhere from 5 to 15% of men are not the actual biological fathers of their children. Following this out 10 generations, there is a 40% chance of a non-paternal event!
Along the same lines, a recent article was published on the Wall Street Journals ‘informedreader’ blog titled “As DNA Tests Spread, So Do Nasty Paternity Surprises.” The article cited Steve Olson’s piece in The Atlantic.
I must admit, I have a deep understanding of this issue and the effect it can have on tested individuals. I have a solid paper trail to Germany back to the 1750’s, but when I received the results of my test, I was shocked to find that my DNA belonged to a small and unique subclade of R1b1c that was only found in England! All of my closest matches also originated in the British Isles.
My first thought was a non-paternal event. I even asked my Mom whether my dad was actually my dad (I was 99.9% joking, of course)! I was so proud of my German heritage, and here I was faced with the possibility that I wasn’t German at all.
However, after a few months, new results showed that other people belonging to the unique subclade of R1b1c also originated in the same area of Germany that my ancestors came from. Thus, rather than worrying about a potential non-paternal event, I was the first person identified with this subclade to be from Germany.
Thanks to Hsien at EyeonDNA for her help!
11 Mart 2008 Salı
Ethical and Legal Issues Surrounding Large-Scale Genomic Databases
I recently came across a review article by Henry T. Greely, a Professor of Law, Professor (by courtesy) of Genetics, and Director of the Center for Law and Bioethics at Stanford. The article is entitled “The Uneasy Ethical and Legal Underpinnings of Large-Scale Genomic Biobanks (pdf)” and was recently published in the Annual Review of Genomics and Human Genetics.
According to Mr. Greely, the identity of participants in large-scale genomic biobanks cannot effectively protected. A biobank is defined as a database of genotypic and phenotypic data. Using genetic information, physical information, or a combination of the two, people can identify an individual in such a large database:
“Someone really interested could get a DNA sample from me - from a licked stamp, a drinking glass, or some tissue - and have it genotyped for a few hundred dollars, but few will have to go to the genomic data; the phenotypic and demographic data will often be sufficient.”
“Eliminating name, mailing address, and social security number does not eliminate identifiers; it just eliminates the easiest identifiers, making the search somewhat more difficult and expensive.”
Unfortunately, it is impossible to remove all the data one could use to identify biobank participants. As Mr. Greely opines, “[t]he more the data is removed or obscured, the more scientific value is lost; the more data is kept, the less real the anonymity.”
So what is the answer? First, consent forms must reveal the fact that while biobanks will attempt to provide anonymity, they simply will not be able to guarantee it. They must also reveal that they cannot inform subjects of all the risks and benefits because many future research topics haven’t even been suggested as of yet. Second, biobanks must prevent participants from being upset by unexpected uses of their materials, either through a thorough consent form, or through general communication with research subjects (such as a mailing list or online community). Third, researchers have a moral (and perhaps legal) duty to inform participants of potentially harmful information uncovered by research. This raises a whole host of questions, including how significant the correlation between a gene and a disease must be to require a participant’s knowledge, how long the biobank should monitor the participant’s genetic information, and whether the biobank should be responsible for genetic counseling.
Mr. Greely raises a number of interesting questions that will have to be answered by governments and companies around the world as the need for biobanks increases and the relative ease of biobank creation decreases.
According to Mr. Greely, the identity of participants in large-scale genomic biobanks cannot effectively protected. A biobank is defined as a database of genotypic and phenotypic data. Using genetic information, physical information, or a combination of the two, people can identify an individual in such a large database:
“Someone really interested could get a DNA sample from me - from a licked stamp, a drinking glass, or some tissue - and have it genotyped for a few hundred dollars, but few will have to go to the genomic data; the phenotypic and demographic data will often be sufficient.”
“Eliminating name, mailing address, and social security number does not eliminate identifiers; it just eliminates the easiest identifiers, making the search somewhat more difficult and expensive.”
Unfortunately, it is impossible to remove all the data one could use to identify biobank participants. As Mr. Greely opines, “[t]he more the data is removed or obscured, the more scientific value is lost; the more data is kept, the less real the anonymity.”
So what is the answer? First, consent forms must reveal the fact that while biobanks will attempt to provide anonymity, they simply will not be able to guarantee it. They must also reveal that they cannot inform subjects of all the risks and benefits because many future research topics haven’t even been suggested as of yet. Second, biobanks must prevent participants from being upset by unexpected uses of their materials, either through a thorough consent form, or through general communication with research subjects (such as a mailing list or online community). Third, researchers have a moral (and perhaps legal) duty to inform participants of potentially harmful information uncovered by research. This raises a whole host of questions, including how significant the correlation between a gene and a disease must be to require a participant’s knowledge, how long the biobank should monitor the participant’s genetic information, and whether the biobank should be responsible for genetic counseling.
Mr. Greely raises a number of interesting questions that will have to be answered by governments and companies around the world as the need for biobanks increases and the relative ease of biobank creation decreases.
The Early Stages of the Genetic Genealogy Revolution
It’s always been my belief that personal genetics (inexpensive whole-genome analysis) will bring about some exciting changes in the field of genetic genealogy. One of the biggest areas of change will undoubtedly be in the area of autosomal genetic testing. (Remember that autosomal testing examines nuclear DNA, which is DNA other than mtDNA, Y-DNA, or X chromsomes).
A new study takes one of the first steps in the genetic genealogy revolution by examining SNP variations in four self-identified American populations – European, Latino/Hispanic, Asian, and African American (see reference below). “These population labels were used, despite the controversy surrounding the correspondence between notions of race and population structure inferred from explicit genetic data, because they are the labels used by NIH, FDA, and many, if not most, biomedical researchers.” The researchers sequenced the exons and flanking regions of 3,873 genes from 76 unrelated individuals.
Results:
SNPs common in one population were frequently not common in other populations. “Moreover, SNPs that were common in two or more populations often differed significantly in frequency from one another, particularly in comparisons of African Americans versus other U.S. populations. These findings indicate that even if the bulk of alleles underlying complex health-related traits are common SNPs, geographic ancestry might well be an important predictor of whether a person carries a risk allele. “
“A frequent claim about human population structure is that most common variation is shared among all populations. This, of course, depends on how population boundaries are defined, but often cited to support such comments are the comparisons of SNP frequencies in pairs of populations in the HapMap data and the Perlegen data. Analyses of these data indicated that common SNPs were frequently both shared and common among populations of predominately African, Asian, and European ancestry. However, population genetic analysis was not the intended goal of either the HapMap or the Perlegen projects, and common, shared SNPs were over sampled by the ascertainment strategies used for each project.”
The structure of common SNP variation differed substantially in African Americans compared with all other U.S. populations studied. “The largest absolute number of SNPs, common SNPs, and private SNPs were found in African Americans. African Americans exhibited the highest proportion of rare SNPs (64%), the lowest proportion of common SNPs (36%), and nearly half of all SNPs (44%) in African Americans were private.”
Although I still think it is too early for useful autosomal testing, this type of data suggests that there is a bright future for geographic ancestry.
Reference: The Structure of Common Genetic Variation in U.S. Populations. Stephen L. Guthery, Benjamin A. Salisbury, Manish S. Pungliya, J. Claiborne Stephens, and Michael Bamshad. The American Society of Human Genetics (Link(pdf, requires subscription)).
HT: Dienekes’ Anthropology Blog
A new study takes one of the first steps in the genetic genealogy revolution by examining SNP variations in four self-identified American populations – European, Latino/Hispanic, Asian, and African American (see reference below). “These population labels were used, despite the controversy surrounding the correspondence between notions of race and population structure inferred from explicit genetic data, because they are the labels used by NIH, FDA, and many, if not most, biomedical researchers.” The researchers sequenced the exons and flanking regions of 3,873 genes from 76 unrelated individuals.
Results:
SNPs common in one population were frequently not common in other populations. “Moreover, SNPs that were common in two or more populations often differed significantly in frequency from one another, particularly in comparisons of African Americans versus other U.S. populations. These findings indicate that even if the bulk of alleles underlying complex health-related traits are common SNPs, geographic ancestry might well be an important predictor of whether a person carries a risk allele. “
“A frequent claim about human population structure is that most common variation is shared among all populations. This, of course, depends on how population boundaries are defined, but often cited to support such comments are the comparisons of SNP frequencies in pairs of populations in the HapMap data and the Perlegen data. Analyses of these data indicated that common SNPs were frequently both shared and common among populations of predominately African, Asian, and European ancestry. However, population genetic analysis was not the intended goal of either the HapMap or the Perlegen projects, and common, shared SNPs were over sampled by the ascertainment strategies used for each project.”
The structure of common SNP variation differed substantially in African Americans compared with all other U.S. populations studied. “The largest absolute number of SNPs, common SNPs, and private SNPs were found in African Americans. African Americans exhibited the highest proportion of rare SNPs (64%), the lowest proportion of common SNPs (36%), and nearly half of all SNPs (44%) in African Americans were private.”
Although I still think it is too early for useful autosomal testing, this type of data suggests that there is a bright future for geographic ancestry.
Reference: The Structure of Common Genetic Variation in U.S. Populations. Stephen L. Guthery, Benjamin A. Salisbury, Manish S. Pungliya, J. Claiborne Stephens, and Michael Bamshad. The American Society of Human Genetics (Link(pdf, requires subscription)).
HT: Dienekes’ Anthropology Blog
J. Craig Venter and Personal Genetics
Wow, what a day for personal genetics. Yesterday, J. Craig Venter’s diploid genome was released (I’m not sure where the sequence is, but the paper is available at PLoS Biology, a OPEN ACCESS journal!).
I know that many people have their gripe about Venter, but seeing a story about personal genetics on the front page of CNN is important. It educates people and helps alleviate fears about genomic sequencing. I think it’s a great opportunity for the field. Here’s a few quotes from the CNN story:
“Venter has just published almost all 6 billion letters, or 96 percent, of his own personal genetic code in the journal PLoS Biology. From diseases to personality traits, it’s the most comprehensive human genome to date. Venter’s gene map provides a new understanding of his genetic destiny, according to the DNA inherited from both his father and his mother.
Venter says it’s just the beginning of a new era of personal genomics. “For the first time, we can answer almost any question of what’s genetic, what’s the environment. Our genes can tell us probabilities of what might happen and give us a chance to do something about it.”
There are also some quotes from George Church, leader of the Personal Genome Project:
“Dr. George Church, a professor of genetics at Harvard Medical School, is working on a DNA test that would identify for the consumer 1 percent of his or her DNA at a cost of $1,000. He says that someday soon, people may be checking their DNA maps as they do their stock portfolios — constantly adjusting to everyday developments and new gene discoveries.
“You’ll have all that information sitting at your desk and as the information flows in you’ll say, ‘I only want to know things of certain type. I don’t want to know about Alzheimer’s, or I don’t want to know about heart disease, or I do, or I want to know about everything, as soon as it comes in,” says Church.
It’s a habit Venter already follows. As more genes are discovered, he says, he constantly checks his own genome.”
For all the genetic genealogists out there, our habit will undoubtedly be comparing our genomes in order to find or identify potential relatives. Sure, curing disease and improving health is important, but genealogy is FUN!
The DNA Network has provided LOTS of coverage of the diploid genome release, so check out the following:
EyeonDNA, here and here.
Bitesizebio
SNPedia
Discovering Biology in a Digital World
evolgen
Genomicron
Scienceroll
The Genealogue (not a member of the DNA Network).
Whew, that should keep you busy for a while!!
I know that many people have their gripe about Venter, but seeing a story about personal genetics on the front page of CNN is important. It educates people and helps alleviate fears about genomic sequencing. I think it’s a great opportunity for the field. Here’s a few quotes from the CNN story:
“Venter has just published almost all 6 billion letters, or 96 percent, of his own personal genetic code in the journal PLoS Biology. From diseases to personality traits, it’s the most comprehensive human genome to date. Venter’s gene map provides a new understanding of his genetic destiny, according to the DNA inherited from both his father and his mother.
Venter says it’s just the beginning of a new era of personal genomics. “For the first time, we can answer almost any question of what’s genetic, what’s the environment. Our genes can tell us probabilities of what might happen and give us a chance to do something about it.”
There are also some quotes from George Church, leader of the Personal Genome Project:
“Dr. George Church, a professor of genetics at Harvard Medical School, is working on a DNA test that would identify for the consumer 1 percent of his or her DNA at a cost of $1,000. He says that someday soon, people may be checking their DNA maps as they do their stock portfolios — constantly adjusting to everyday developments and new gene discoveries.
“You’ll have all that information sitting at your desk and as the information flows in you’ll say, ‘I only want to know things of certain type. I don’t want to know about Alzheimer’s, or I don’t want to know about heart disease, or I do, or I want to know about everything, as soon as it comes in,” says Church.
It’s a habit Venter already follows. As more genes are discovered, he says, he constantly checks his own genome.”
For all the genetic genealogists out there, our habit will undoubtedly be comparing our genomes in order to find or identify potential relatives. Sure, curing disease and improving health is important, but genealogy is FUN!
The DNA Network has provided LOTS of coverage of the diploid genome release, so check out the following:
EyeonDNA, here and here.
Bitesizebio
SNPedia
Discovering Biology in a Digital World
evolgen
Genomicron
Scienceroll
The Genealogue (not a member of the DNA Network).
Whew, that should keep you busy for a while!!
Genetic Genealogy In the News
There is so much information about genetic genealogy in the news right now that I am having a hard time keeping up. That, of course, is good news. So here is a round-up of some of the best from the web:
“Seeking Columbus’s Origins, With a Swab” is an article in today’s New York Times (HT: Liz). Scientists and genetic genealogists hope to use Y-DNA to compare DNA that might be Columbus’s to modern-day people with a related surname.
“Genetic Genealogy Mildly Hot” is a post by Hsien at Eye On DNA that explains why “family tree dna” was one of the top 100 searches at Google Trends yesterday. Got a guess?
In “60 Minutes on DNA: Deja Vu All Over Again“, Megan Smolenyak looks at Sunday’s 60 Minutes segment about genetic genealogy. It’s a brilliant post, especially with the following sentence:
“Since I’ve been watching this same formula repeat itself since 2001, I’ve developed a pet peeve about the built-in, patronizing assumption that genealogists are too dense to understand the fundamentals of what DNA can and can’t do — rather than the reality that we’re pioneers delighted with the prospect of learning what had previously been unknowable and well aware of the limitations.”
We’re pioneers, people! If there is anyone being tested who doesn’t understand the limitations of genetic genealogy, then they’re not reading The Genetic Genealogist, or Megan’s Roots World.
There’s some new information about 23andMe’s latest round of venture capital funding.
“Genomics: The Personal Side of Genomics” is a round-up by Nature of some of the latest innovations in DNA sequencing. A nice discussion of some aspects of The Personal Genome Project (HT: Brian).
“The DNA Cracker: Closing the Book on Jack” is an article about using DNA databases to find relatives and identify potential suspects for criminal investigations. The article is also largely about Bryan Sykes, the founder of Oxford Ancestors (HT: Hsien).
And finally, the Sorenson Molecular Genealogy Foundation (SMGF) has announced that its DNA database will expand by at least 30,000 samples this year, due to expansive collection projects in a number of regions around the world.
“Seeking Columbus’s Origins, With a Swab” is an article in today’s New York Times (HT: Liz). Scientists and genetic genealogists hope to use Y-DNA to compare DNA that might be Columbus’s to modern-day people with a related surname.
“Genetic Genealogy Mildly Hot” is a post by Hsien at Eye On DNA that explains why “family tree dna” was one of the top 100 searches at Google Trends yesterday. Got a guess?
In “60 Minutes on DNA: Deja Vu All Over Again“, Megan Smolenyak looks at Sunday’s 60 Minutes segment about genetic genealogy. It’s a brilliant post, especially with the following sentence:
“Since I’ve been watching this same formula repeat itself since 2001, I’ve developed a pet peeve about the built-in, patronizing assumption that genealogists are too dense to understand the fundamentals of what DNA can and can’t do — rather than the reality that we’re pioneers delighted with the prospect of learning what had previously been unknowable and well aware of the limitations.”
We’re pioneers, people! If there is anyone being tested who doesn’t understand the limitations of genetic genealogy, then they’re not reading The Genetic Genealogist, or Megan’s Roots World.
There’s some new information about 23andMe’s latest round of venture capital funding.
“Genomics: The Personal Side of Genomics” is a round-up by Nature of some of the latest innovations in DNA sequencing. A nice discussion of some aspects of The Personal Genome Project (HT: Brian).
“The DNA Cracker: Closing the Book on Jack” is an article about using DNA databases to find relatives and identify potential suspects for criminal investigations. The article is also largely about Bryan Sykes, the founder of Oxford Ancestors (HT: Hsien).
And finally, the Sorenson Molecular Genealogy Foundation (SMGF) has announced that its DNA database will expand by at least 30,000 samples this year, due to expansive collection projects in a number of regions around the world.
10 DNA Testing Myths Busted
1. Genetic genealogy is only for hardcore genealogists.
Wrong! If you’ve ever wondered about the origins of your DNA, or about your direct paternal or maternal ancestral line, then genetic genealogy might be an interesting way to learn more. Although DNA testing of a single line, such as through an mtDNA test, will only examine one ancestor out of 1024 potential ancestors at 10 generations ago, this is a 100% improvement over 0 ancestors out of 1024. If you add your father’s Y-DNA, this is a 200% improvement. Now add your mother’s mtDNA, and so on. However, with this in mind, please note the next myth:
2. I’m going to send in my DNA sample and get back my entire family tree.
Sorry. DNA alone cannot tell a person who their great-grandmother was, or what Italian village their great-great grandfather came from. Genetic genealogy can be an informative and exciting addition to traditional research, and can sometimes be used to answer specific genealogical mysteries.
3. I would like to try genetic genealogy, but I’m terrified of needles.
Good news! Genetic genealogy firms don’t use blood samples to collect cells for DNA testing. Instead, these companies send swabs or other means to gently obtain cells from the cheek and saliva.
4. I would like to test my ancestor’s DNA, but they died years ago.
You don’t always need your ancestor’s DNA to get useful information from a genetic genealogy test. If you are male, you contain the Y-chromosome (Y-DNA) that was given to you by your father, who received it from his father, and so on. Both males and females have mitochondrial DNA (mtDNA), which was passed on to them by their mother, who received it from her mother, and so on. Everyone of us contains DNA (Y-DNA and/or mtDNA) from our ancestors that can be studied by genetic genealogy.
5. I want to test my mother’s father’s Y-DNA, but since he didn’t pass on his Y-chromosome to my mother, I’m out of luck.
Wrong! There is a very good chance that there is another source of that same Y-DNA. For instance, does your mother have a brother (your uncle) who inherited the Y-DNA from his father? Or does your mother’s father have a brother (your great-uncle) who would be willing to submit DNA for the test? Sometimes there might not be an obvious source of “lost” Y-DNA, or no one in the family is willing to take a DNA test. The secret to solving this problem is to do what every good genealogist does – use traditional genealogical research (paper records, census information, etc) to “trace the DNA”. Follow the line back while tracing descendants in order to find someone who is interested in learning more about their Y-DNA. This applies to finding a source of mtDNA as well.
6. Only men can submit DNA for genetic genealogy tests, since women do not have the Y-chromosome.
Wrong! Most genetic genealogy testing companies also offer mtDNA testing. Both men and women have mtDNA in their cells and can submit that DNA for testing. In addition, women can test their father’s, brother’s, or some other male relative’s Y-DNA to learn more about their paternal ancestral line, even though they did not inherit the Y-chromosome.
7. My genetic genealogy test will also reveal my propensity for diseases associated with the Y-chromosome and mtDNA.
Wrong, thank goodness. Most of the information obtained by genetic genealogy tests has no known medical relevancy, and these firms are not actively looking for medical information. It is important to note, however, that some medical information (such as infertility detected by DYS464 testing or other diseases detectable by a full mtDNA sequence) might inadvertently be revealed by a genetic genealogy test.
8. I don’t like the thought of a company having my DNA on file or my losing control over my DNA sample.
This is, of course, an understandable concern. However, most testing firms give a client two options: the DNA is either immediately destroyed once the tests are run, or it is securely stored for future testing. If the DNA is stored, the firm will typically destroy the DNA upon request. If the long-term storage of DNA is a concern, be sure to research the company’s policy before sending in a sample.
9. If my test reveals Native American ancestry, I plan to join a particular Native American affiliation group.
Although genetic genealogy can potentially reveal Native American ancestry (for instance, my mtDNA belongs to the Native American haplogroup A2), it is incredibly unlikely that this information will be sufficient to positively identify the specific source of the lineage (such as a tribe) or allow membership in a particular Native American affiliation.
10. My DNA is so boring that genetic genealogy would be a waste of time and money.
Very wrong! A person’s DNA is a very special possession – although everyone has DNA, everyone’s DNA is different (okay, except identical twins – if your identical twin has been tested, you should think twice about buying the same test!). As humans settled the world, Y-DNA and mtDNA spread and mixed randomly. As a result, it is impossible to guess with 100% assurance that a person’s Y-DNA or mtDNA belongs to a particular haplogroup (a related family of DNA sequences) without DNA testing.
BONUS MYTH: My genetic genealogy test says that my mtDNA belongs to Haplogroup A2. Juanita the Ice Maiden, a frozen mummy discovered in the Andes Mountains in Peru also has Haplogroup A2 mtDNA. Therefore, she must be my ancestor!
Wrong! If you’ve ever wondered about the origins of your DNA, or about your direct paternal or maternal ancestral line, then genetic genealogy might be an interesting way to learn more. Although DNA testing of a single line, such as through an mtDNA test, will only examine one ancestor out of 1024 potential ancestors at 10 generations ago, this is a 100% improvement over 0 ancestors out of 1024. If you add your father’s Y-DNA, this is a 200% improvement. Now add your mother’s mtDNA, and so on. However, with this in mind, please note the next myth:
2. I’m going to send in my DNA sample and get back my entire family tree.
Sorry. DNA alone cannot tell a person who their great-grandmother was, or what Italian village their great-great grandfather came from. Genetic genealogy can be an informative and exciting addition to traditional research, and can sometimes be used to answer specific genealogical mysteries.
3. I would like to try genetic genealogy, but I’m terrified of needles.
Good news! Genetic genealogy firms don’t use blood samples to collect cells for DNA testing. Instead, these companies send swabs or other means to gently obtain cells from the cheek and saliva.
4. I would like to test my ancestor’s DNA, but they died years ago.
You don’t always need your ancestor’s DNA to get useful information from a genetic genealogy test. If you are male, you contain the Y-chromosome (Y-DNA) that was given to you by your father, who received it from his father, and so on. Both males and females have mitochondrial DNA (mtDNA), which was passed on to them by their mother, who received it from her mother, and so on. Everyone of us contains DNA (Y-DNA and/or mtDNA) from our ancestors that can be studied by genetic genealogy.
5. I want to test my mother’s father’s Y-DNA, but since he didn’t pass on his Y-chromosome to my mother, I’m out of luck.
Wrong! There is a very good chance that there is another source of that same Y-DNA. For instance, does your mother have a brother (your uncle) who inherited the Y-DNA from his father? Or does your mother’s father have a brother (your great-uncle) who would be willing to submit DNA for the test? Sometimes there might not be an obvious source of “lost” Y-DNA, or no one in the family is willing to take a DNA test. The secret to solving this problem is to do what every good genealogist does – use traditional genealogical research (paper records, census information, etc) to “trace the DNA”. Follow the line back while tracing descendants in order to find someone who is interested in learning more about their Y-DNA. This applies to finding a source of mtDNA as well.
6. Only men can submit DNA for genetic genealogy tests, since women do not have the Y-chromosome.
Wrong! Most genetic genealogy testing companies also offer mtDNA testing. Both men and women have mtDNA in their cells and can submit that DNA for testing. In addition, women can test their father’s, brother’s, or some other male relative’s Y-DNA to learn more about their paternal ancestral line, even though they did not inherit the Y-chromosome.
7. My genetic genealogy test will also reveal my propensity for diseases associated with the Y-chromosome and mtDNA.
Wrong, thank goodness. Most of the information obtained by genetic genealogy tests has no known medical relevancy, and these firms are not actively looking for medical information. It is important to note, however, that some medical information (such as infertility detected by DYS464 testing or other diseases detectable by a full mtDNA sequence) might inadvertently be revealed by a genetic genealogy test.
8. I don’t like the thought of a company having my DNA on file or my losing control over my DNA sample.
This is, of course, an understandable concern. However, most testing firms give a client two options: the DNA is either immediately destroyed once the tests are run, or it is securely stored for future testing. If the DNA is stored, the firm will typically destroy the DNA upon request. If the long-term storage of DNA is a concern, be sure to research the company’s policy before sending in a sample.
9. If my test reveals Native American ancestry, I plan to join a particular Native American affiliation group.
Although genetic genealogy can potentially reveal Native American ancestry (for instance, my mtDNA belongs to the Native American haplogroup A2), it is incredibly unlikely that this information will be sufficient to positively identify the specific source of the lineage (such as a tribe) or allow membership in a particular Native American affiliation.
10. My DNA is so boring that genetic genealogy would be a waste of time and money.
Very wrong! A person’s DNA is a very special possession – although everyone has DNA, everyone’s DNA is different (okay, except identical twins – if your identical twin has been tested, you should think twice about buying the same test!). As humans settled the world, Y-DNA and mtDNA spread and mixed randomly. As a result, it is impossible to guess with 100% assurance that a person’s Y-DNA or mtDNA belongs to a particular haplogroup (a related family of DNA sequences) without DNA testing.
BONUS MYTH: My genetic genealogy test says that my mtDNA belongs to Haplogroup A2. Juanita the Ice Maiden, a frozen mummy discovered in the Andes Mountains in Peru also has Haplogroup A2 mtDNA. Therefore, she must be my ancestor!
Links From The Genetic Genealogist
In order to clean out posts I’ve been saving in Google Reader (does anyone else keep posts in Reader until you’ve blogged about them?), I decided to have a potpourri day. The following are links to interesting articles around the blogosphere. And Happy Halloween!
Pedro at Public Rambling has The Fortune Cookie Genome, a ’science fiction’ post about picking up the results of his whole genome scan from his genetic advisor. Of course, it’s only science ‘fiction’ until it’s science ‘reality’!
The Women’s Bioethic Project has an article about DNA Testing Without Consent, which asks whether there should be a ‘reverse’ statute of limitations for testing DNA from famous dead people. The article was written in response to a recent story in Parade. I talked about this briefly back in August (see “DNA From the Dead“), and I’m working on a post about “Discarded DNA and the Constitution”, so stick around. HT: Eye on DNA.
Tim at Genealogy Reviews Online continues his review of DNA Ancestry with DNA Ancestry Review Part 2. In this installment, Tim describes the DNA collection process.
At The Tree of Life, Jonathan Eisen presents the Overselling Genomics award to Newsweek as a result of their “10 Hottest Nerds” story. Personally, I think any story that brings science to the masses in an connectable way is beneficial, but I agree that the lack of women on the list was a huge oversight.
At genomeboy.com, Misha Angrist dissects the recent Portfolio piece about personal genomics companies such as 23andMe and Navigenics. He also highlights that familiar $12.5 billion “potential market” quote. I wish I knew who and how that number has come from.
And finally, Alan Boyle at Cosmic Log writes about The Secrets in Your Genome, which is about the International HapMap Consortium’s latest release:
Pedro at Public Rambling has The Fortune Cookie Genome, a ’science fiction’ post about picking up the results of his whole genome scan from his genetic advisor. Of course, it’s only science ‘fiction’ until it’s science ‘reality’!
The Women’s Bioethic Project has an article about DNA Testing Without Consent, which asks whether there should be a ‘reverse’ statute of limitations for testing DNA from famous dead people. The article was written in response to a recent story in Parade. I talked about this briefly back in August (see “DNA From the Dead“), and I’m working on a post about “Discarded DNA and the Constitution”, so stick around. HT: Eye on DNA.
Tim at Genealogy Reviews Online continues his review of DNA Ancestry with DNA Ancestry Review Part 2. In this installment, Tim describes the DNA collection process.
At The Tree of Life, Jonathan Eisen presents the Overselling Genomics award to Newsweek as a result of their “10 Hottest Nerds” story. Personally, I think any story that brings science to the masses in an connectable way is beneficial, but I agree that the lack of women on the list was a huge oversight.
At genomeboy.com, Misha Angrist dissects the recent Portfolio piece about personal genomics companies such as 23andMe and Navigenics. He also highlights that familiar $12.5 billion “potential market” quote. I wish I knew who and how that number has come from.
And finally, Alan Boyle at Cosmic Log writes about The Secrets in Your Genome, which is about the International HapMap Consortium’s latest release:
Dna Source
By the early 1970s, Sanger was interested in deoxyribonucleic acid (DNA). DNA sequence studies had not developed because of the immense size of DNA molecules and the lack of suitable enzymes to cleave DNA into smaller pieces. Building on the enzyme copying approach used by the Swiss chemist Charles Weissmann in his studies on bacteriophage RNA, Sanger began using the enzyme DNA polymerase to make new strands of DNA from single-strand templates, introducing radioactive nucleotides into the new DNA. DNA polymerase requires a primer that can bind to a known region of the template strand. Early success was limited by the lack of suitable primers. Sanger and British colleague Alan R. Coulson developed the “plus and minus” method for rapid DNA sequencing. It represented a radical departure from earlier methods in that it did not utilize partial hydrolysis. Instead, it generated a series of DNA molecules of varying lengths that could be separated by using polyacrylamide gel electrophoresis. For both plus and minus systems, DNA was synthesized from templates to generate random sets of DNA molecules from very short to very long. When both plus and minus sets were separated on the same gel, the sequence could be read from either system, one confirming the other. In 1977 Sanger's group used this system to deduce most of the DNA sequence of bacteriophage FX174, the first complete genome to be sequenced.
DNA Analysis and Intra-Agency Databases
In the 1990’s DNA testing started to become popular particularly in the area of Law Enforcement. Old pieces of evidence to include hair, blood and semen which were once not able to provide evidence now were able to be processed and evidence and a DNA profile could be extracted from the materials. Thanks to DNA many unsolved cased were able to be solved and many suspects of crimes were finally able to be charged. DNA has also helped the innocent from wrongful incarceration. DNA evidence is becoming mandatory in states in terms of death row inmates and proving that the right person is behind bars. In 2000, Illinois Governor George Ryan announced his plan to suspend all of the states executions indefinitely. Governor Ryan’s made this landmark statement after DNA testing showed that 13 Illinois death-row prisoners could not have committed the capital crimes of which they were convicted. DNA is not just putting people in prison; it is also ensuring that those in prison should be there. DNA is being used to confirm the conviction and ensure that the right person is serving time for the crime. In what is bring described as the first effort of it’s kind San Diego prosecutors are reviewing hundreds of old cases to see if longtime prison inmates can be cleared by DNA evidence. If evidence is found, the San Diego County District Attorney’s office will have it tested for free if an inmate agrees. Not only does this get innoscent people out of prison it also helps to build out the national DNA database. Part of the DNA testing of inmates is that the inmate’s DNA will end up in a national database where it may be used to solve other cases which have gone unsolved. San Diego Country Prosecutors are looking at a total of 560 criminal cases. Since DNA has been introduced thousands of suspects and prison inmates have been cleared and released as a result of DNA evidence showing they could not have been responsible for the crime. A popular case that outlined this is the Larry Youngblood case. Larry Youngblood was convicted in 1985 of child molestation, sexual assault, and kidnapping. He was sentenced to ten years and six months in prison. In October 1983, a ten year old boy was abducted from a carnival in Pima County, Arizona, and molested and sodomized repeatedly for over an hour by a middle aged man. The victim was taken to a hospital, where the staff collected semen samples from his rectum as well as the clothing he was wearing at the time of the assault. Based on the boy's description of the assailant as a man with one disfigured eye, Youngblood was charged with the crime. He maintained his innocence at trial, but the jury convicted him, based largely on the eyewitness identification of the victim. No serological tests were conducted before trial, as the police improperly stored the evidence and it had degraded. Expert witnesses at trial stated that, had the evidence been stored correctly, test results might have demonstrated conclusively Youngblood's innocence. Larry Youngblood appealed his conviction, claiming the destruction of potentially exculpatory evidence violated his due process rights, and the Arizona Court of Appeals set aside his conviction. He was released from prison, three years into his sentence, but in 1988, the Supreme Court reversed the lower court's ruling, and his conviction was reinstated (Arizona v. Youngblood, 488 U.S. 51). Youngblood remained free as the case made its way through the Arizona appellate court system a second time, but returned to prison in 1993, when the Arizona Supreme Court reinstated his conviction. In 1998, Youngblood was released on parole, but was sent back to prison in 1999 for failing to register his new address, as required by Arizona sex offender laws. In 2000, upon request from his attorneys, the police department tested the degraded evidence using new, sophisticated DNA technology. Those results exonerated Youngblood, and he was released from prison in August 2000. The district attorney's office dismissed the charges against Larry Youngblood that year. In 1990, the FBI established its database containing genetic profiles from unsolved crimes and from convicted offenders. In October 1998, the FBI's National DNA Index System (NDIS) became operational. The database is the (CODIS) Combined DNA Index System, a computerized forensic database of DNA “profiles” of offenders convicted of serious crimes (such as rape, other sexual assaults, murder, and certain crimes against children), as well as DNA profiles from unknown offenders. CODIS generates investigative leads in crimes where biological evidence is recovered from the crime scene using two indexes: the forensic and offender indexes. By 1998, every state had enacted legislation establishing a CODIS database and requiring that DNA from offenders convicted of certain serious crimes be entered into the system. Today, the CODIS database contains about 400,000 DNA profiles, and the number is growing. CODIS is implemented as a circulated database with three tiers - local, state, and national. NDIS is the highest level in the CODIS hierarchy, and enables the laboratories participating in the CODIS Program to exchange and compare DNA profiles on a national level. All DNA profiles originate at the local level (LDIS), then flow to the state (SDIS) and national levels. SDIS allows laboratories within states to exchange DNA profiles. The tiered approach allows state and local agencies to operate their databases according to their specific legislative or legal requirements. It is being enhanced daily through the work of federal, state, and local law enforcement agencies who take DNA samples from biological evidence gathered at crime scenes and from offenders themselves. The computerized CODIS system can rapidly identify a perpetrator when it finds a match between an evidence sample and a stored profile. As of 2003, the database had profiled approxminaly 66,000 unsolved cases and more than 1.5 million convicted offenders. Matches made among profiles in the Forensic Index can link crime scenes together; and even identifying serial offenders. Based on a match, police in multiple jurisdictions can coordinate their respective investigations, and share the leads they developed independently. Matches made between the Forensic and Offender indexes provide investigators with the identity of the perpetrator(s). After CODIS identifies a potential match, qualified DNA analysts in the laboratories contact each other to validate or refute the match. Everyone benefits from having a national DNA database and DNA information has helped many victims, families and people who were either the victim of a crime or victimized by the criminal justice system and wrongfully convicted. The DNA database provides a very large resource which provides a conclusive way to show whether or not someone had anything to do with a crime. The database has also closed thousands of cases which would have otherwise gone unsolved indefinitely.
DNA Testing - Are You Raising Someone Else's Child?
Paternity Testing – Are you raising someone else’s child?
Back in the 1700s, the best way to determine paternity was by a good hard look at the child, followed by a good hard look at the father. Enough coincidences and maybe a relationship could be proposed. A hundred years later, eye colour was discovered to be a paternity identifier. This theory has had its flaws exposed because of recent DNA advances. We now know that eye colour is determined by at least six alleles, or genetic markers. Paternity testing has become a lot easier and affordable over the past few years due to advances in DNA science. Although an estimated 200,000 DNA tests are conducted each year by states needing to sort child-support and welfare issues, few people are willing to conduct their own at-home paternity test because they don’t realize the simplicity and convenience of an at-home paternity test.
How does a home DNA test work?
Paternity testing requires a painless sample from both the child and possible father. Even without a sample from the mother, DNA paternity test results are up to 99.9999% accurate–that’s one-in-a-million odds your results are incorrect. Most companies provide a free home kit for you to provide the samples and require you to send the kit back to the laboratory with the accompanying fee.
Because many companies are aware of the discomfort of drawing blood from a child in order to get a sample, buccal (mouth) swabs are being accepted as an alternative. By gently massaging the inside of the child’s mouth, cheek cells are collected. These cells are then sent to the lab for testing. Labs analyze up to sixteen genetic markers of the child and match them against the markers of the alleged father. Because each of us receives half our genetic markers from each parent, the results of DNA paternity testing are still accurate without the DNA information of the mother. Most labs will have results in 10 days and charge about $290 for a basic paternity verification test.
What else can a DNA test do?
DNA kits can also be used to analyze siblingship, establish cousin or grandparent relationships, determine twin zygosity (i.e. whether twins are fraternal or identical), identify ancestral origin, verify Native American decent, assure parents they left the hospital with the right baby, and most important, provide legal evidence – be prepared to pay a bit more for legal tests. Legal tests can be used to settle adoption issues, settle child-support disputes, and provide information for immigration files.
How to choose a DNA laboratory
Accreditation is a vital part of choosing a laboratory. Accredited labs have an annual audit and inspection, undergo internal and external reviews, and have their equipment calibrated for accuracy. Look for an ISO and/or AABB certification. Accredited labs will have a good reputation and near 100% track record for court cases.
Look for hidden fees. Some companies will charge you for the kit and then charge you again for the results. Also, double check when you order your kit that you’re only buying the results you need.
Ask about privacy. Make sure that your identity and intentions are kept secure.
Enjoy piece of mind
Be confident that the questions you have can be answered. DNA testing is safe and stress-free. Find a free kit and an information packet and you’re on your way to getting the piece of mind that you deserve.
Back in the 1700s, the best way to determine paternity was by a good hard look at the child, followed by a good hard look at the father. Enough coincidences and maybe a relationship could be proposed. A hundred years later, eye colour was discovered to be a paternity identifier. This theory has had its flaws exposed because of recent DNA advances. We now know that eye colour is determined by at least six alleles, or genetic markers. Paternity testing has become a lot easier and affordable over the past few years due to advances in DNA science. Although an estimated 200,000 DNA tests are conducted each year by states needing to sort child-support and welfare issues, few people are willing to conduct their own at-home paternity test because they don’t realize the simplicity and convenience of an at-home paternity test.
How does a home DNA test work?
Paternity testing requires a painless sample from both the child and possible father. Even without a sample from the mother, DNA paternity test results are up to 99.9999% accurate–that’s one-in-a-million odds your results are incorrect. Most companies provide a free home kit for you to provide the samples and require you to send the kit back to the laboratory with the accompanying fee.
Because many companies are aware of the discomfort of drawing blood from a child in order to get a sample, buccal (mouth) swabs are being accepted as an alternative. By gently massaging the inside of the child’s mouth, cheek cells are collected. These cells are then sent to the lab for testing. Labs analyze up to sixteen genetic markers of the child and match them against the markers of the alleged father. Because each of us receives half our genetic markers from each parent, the results of DNA paternity testing are still accurate without the DNA information of the mother. Most labs will have results in 10 days and charge about $290 for a basic paternity verification test.
What else can a DNA test do?
DNA kits can also be used to analyze siblingship, establish cousin or grandparent relationships, determine twin zygosity (i.e. whether twins are fraternal or identical), identify ancestral origin, verify Native American decent, assure parents they left the hospital with the right baby, and most important, provide legal evidence – be prepared to pay a bit more for legal tests. Legal tests can be used to settle adoption issues, settle child-support disputes, and provide information for immigration files.
How to choose a DNA laboratory
Accreditation is a vital part of choosing a laboratory. Accredited labs have an annual audit and inspection, undergo internal and external reviews, and have their equipment calibrated for accuracy. Look for an ISO and/or AABB certification. Accredited labs will have a good reputation and near 100% track record for court cases.
Look for hidden fees. Some companies will charge you for the kit and then charge you again for the results. Also, double check when you order your kit that you’re only buying the results you need.
Ask about privacy. Make sure that your identity and intentions are kept secure.
Enjoy piece of mind
Be confident that the questions you have can be answered. DNA testing is safe and stress-free. Find a free kit and an information packet and you’re on your way to getting the piece of mind that you deserve.
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