Archive for March, 2010

It’s a family reunion on the internet

Now that I’ve received my results, I’ve had time to play around with the 23andMe social network. 23andMe provides you with much more than a genetic test: the infrastructure that the company offers to connect with other users is astounding.

23andMe has provided me with a list of potential relatives that are currently on the network through the Relative Finder tool. The tool allows me to look for shared DNA segments in order to predict common ancestors and the degrees of separation between us.

By using Relative Finder, I found that I have a lot of predicted third cousins, people I share great-great grandparents with, in the 23andMe network. However, the relationship could actually be anywhere from third to tenth cousins. According to 23andMe, there are 987 users that I am at some point related to. It is actually very common for Ashkenazi Jews, as I am, to be genetically closely related despite geographical distance (Kopelman).

Another feature is the genome-sharing tool. This tool allows me to compare my genomic information with other members of 23andMe to look for a percent similarity between us. I can also compare whether I and another user share genetic information that confers to specific phenotypic traits, but since I only have the ancestry edition of the 23andMe genetic test, these traits are limited to non-medical phenotypes such bitter tasting, circadian rhythm, and endurance. Genome sharing is not limited to the users that are identified by 23andMe as my “relatives.” Linda Avey, one of the original co-founders of 23andMe, is not on my list of potential cousins, but she graciously accepted my genome-sharing request and now I can compare my genomic information to hers.

Yet another networking opportunity provided by the site is the community discussion forums.  Here, members post in groups such as maternal and paternal haplotype groups, ethnicity groups, and geographical ancestry groups. On the discussion board, users compare family histories and common last names, ancestry success stories, and even medical histories.

This model of networking around genetics and health isn’t unique to 23andMe. Many companies are emerging that offer connectivity and empowerment tools to complement their health or genetics-related products and services. Financial analysts at PricewaterhouseCoopers have also predicted that more companies like this will also emerge in the near future to capitalize on the trend of personalized medicine (PwC Health Research Institute).

Works cited in this post
Kopelman, Naama M. “Genomic Microsatellites Identify Shared Jewish Ancestry Intermediate between Middle Eastern and European Populations.” BMC Genetics 10.80 (2009). Print.
PwC Health Research Institute. The New Science of Personalized Medicine. Publication. PricewaterhouseCoopers, 17 Dec. 2009. Web. 20 Jan. 2010.

March 29, 2010 at 6:41 pm Leave a comment

And the results are in!

First, a little bit more about Phylogenetics

I spoke in the previous post about mtDNA and the estimated rate of mutation in the mitochondrial genome. Researchers have found that genetic variation in mtDNA can be grouped into distinct lineages, many of which are only found in certain parts of the world (Devor). Since mitochondria are passed only from mother to offspring, researchers have predicted the existence of a common mitochondrial ancestor, affectionately called “Mitochondrial Eve” (Devor). Extrapolating the mtDNA mutation rate, researchers have also predicted how long ago Mitochondrial Eve lived and how long ago the common lineages diverged (Cann).

The oldest haplogroups, L1, L2, and L3, originated in Africa. L3 then formed haplogroups M and N in Northeast Africa. Scientists believe that the original inhabitants of Europe and Asia had mitochondrial DNA from the M and N haplogroups and began colonizing the continents between 60,000 to 80,000 years ago. Haplogroups H, I, J, N1b, T, U,V, W, and X are descendents of haplogroup N and constitute the majority of mitochondrial haplogroups in Europe (Shriver).

My Results: Hi, I’m Haplogroup H3!

The European lineages, including haplogroup H, arrived in Europe 40,000 to 50,000 years ago, near the end of the Ice Age (Devor). According to 23andMe, the H3 haplogroup arose during the Ice Age in northern Iberia. At the end of the Ice Age, Haplogroup H3 migrated in two groups, one to present-day France and the British Isles and the other to Italy and Sardinia, and later to Hungary. Haplogroup H3 is also found throughout Western Europe due to the northward migrations after the conclusion of the Ice Age. H3 is extremely rare outside Europe (“Maternal Lineage”).

My Genetic Similarity Map

My results say that I am 67.69% Southern European, and more specifically, Italian. My results also say that I am 67.55% similar to Northern Europeans and 67.31% similar to Near Easterners. These results are not entirely unexpected, but pretty exciting nonetheless. I am obsessed with Italian food and all things Italy, and I couldn’t be happier to be ancestrally Italian.

Works Cited
Cann, Rebecca L., Mark Stoneking, and Allan C. Wilson. “Mitochondrial DNA and Human Evolution.” Nature 325 (1987): 31-35.
Devor, Eric J. Mitochondrial DNA. Publication. Integrated DNA Technologies, 2005. Web. 1 Mar. 2010.
“Maternal Lineage.” 23andMe. Web. 22 Mar. 2010.

March 23, 2010 at 5:03 pm 2 comments

So what is genetic ancestry testing, really?

Genetic ancestry testing and the encompassing field of genetic genealogy have experienced somewhat of a boom in popularity in the past ten years. According to an article by Mark Shriver and Rick Kittles, genealogical research is one of the fastest growing hobbies in America (611). The advent and growing accessibility of biotechnologies have intensified this growth in interest in one’s genetic and genealogical background. By my count, at least twenty-five firms currently sell genetic ancestry tests over the internet, and it appears that hundreds of thousands of people are buying them. Blaine Bettinger, author of the popular blog “The Genetic Genealogist,” has estimated that over half a million consumers purchased genetic ancestry testing in 2008, and he predicts that this number grows by as much as 100,000 every year (Bettinger).

Consumers purchase and use genetic genealogy tools for a myriad of reasons. Some hope to identify relatives and connect with them through an established social network. Others aim to confirm existing genealogical records with genetic information. Many consumers hope to create a connection between their ancestral homeland or ethnic group (Bolnick). My personal reason is a bit less scholarly: I’m a technophile at heart, and I think genetic testing is amazingly cool. However, I do have access to a pretty significant archive of family history and genealogical records, and I’m looking forward to seeing if the family tree matches the genetic test results.

The science behind genetic ancestry testing

There are three main categories of genetic ancestry tests. Mitochondrial DNA (mtDNA) tests sequence or genotype part of the mitochondrial genome. There is an area of the mitochondrial genome that does not contain any protein-coding sequences, allowing mutations to freely accumulate without causing deleterious harm. This area, known as the hypervariable region, allows researchers and genealogists to study neutral genetic variation (Stoneking). Additionally, the mitochondrial genome is maternally inherited, and it exists and recombines separately from the nuclear genome and (Shriver). Because only female gametes contribute mitochondria, each person only has one mitochondrial ancestor per generation. Scientists have estimated the mitochondrial mutation rate, and when coupled with the amount of genetic variation between two mitochondrial sequences, one can predict how long ago the two sequences (which, presumably, belong to two individuals) shared a common ancestor (Devor).

The second kind of genetic test sequences or genotypes the Y-chromosome. Similar to mtDNA, Y-chromosome DNA does not recombine, making it a perfect source of markers for patrilineal genealogy (Shriver). This test can, however, only be done on those who have a Y-chromosome, which means I’m out of luck. I could get the results of my patrilineal ancestry if I convinced a male relative to donate his spit to my Responsible Genomics project, but that would require another $399 ancestry test. Looks like my full genetic genealogy will have to wait until later.

The third kind of genetic test uses ancestry informative markers on the autosomal chromosomes. These population-specific markers do not focus on a single lineage, as mtDNA and Y-chromosome tests do. Rather, these autosomal markers can be used to paint a picture of one’s ancestry from many different populations.

What Technology 23andMe Uses

23andMe offers genetic ancestry tests, as well as health-related genetic tests. For this project, I used the “Ancestry Edition” for the genealogy-only services. 23andMe uses Illumina’s HumanHap 550+ BeadChip technology, an array-based chip that analyzes over 550,000 single nucleotide polymorphisms, or SNPs.

23andMe takes the results of the SNP array and compares it to their reference database of haplotypes that have been identified in specific populations. 23andMe’s reference database is based on the Human Genome Diversity Panel and Illumina’s iControlDB database (Macpherson).

Now that I know more about what I’m really getting with my genetic ancestry test, I’m even more excited to receive my results! Let the waiting game begin!

Works cited in this post
Bettinger, Blaine. The Genetic Genealogist. 2008. Web. 12 Apr. 2010.
Bolnick, Deborah, Duana Fullwiley, and Troy Duster, et al. “The Science and Business of Genetic Ancestry Testing.” Science 318 (2007): 399-400. Print.
Devor, Eric J. Mitochondrial DNA. Publication. Integrated DNA Technologies, 2005. Web. 1 Mar. 2010.
Macpherson, Mike, Werner, Greg, Mirza, Iram, et al. Global Similarity’s Genetic Similarity Map. White Paper 24-03. 23andMe.
Shriver, Mark D., and Rick A. Kittles. “Genetic Ancestry and the Search for Personalized Genetic Histories.” Nature Reviews Genetics 5 (2005): 611-18. Print.
Stoneking, Mark. Hypervariable Sites in the mtDNA Control Region Are Mutational Hotspots. The American Journal of Human Genetics, Volume 67, Issue 4, Pages 1029-1032

March 16, 2010 at 6:37 pm Leave a comment

The 23andMe genetic test

The 23andMe genetic ancestry test has come in the mail!

Inside the box I find very clear instructions, along with a test-tube and a funky looking spit-catching mouthpiece.

It’s pretty easy: spit (and spit, and spit, and spit until your cheeks hurt) in the tube, then seal it up and send it off to California!

And that’s it! I have to wait patiently for 2-4 weeks while 23andMe’s laboratory processes my sample. I think the waiting will be the most difficult part of this process.

March 4, 2010 at 4:03 pm Leave a comment



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