What European DNA Can Say About Ancestry, Disease Risk, and Cultural Traits

All the drama in the European Union right now — the debt crisis, the North-South divide and the kvetching over the wisdom of a common currency — has reignited talk about the cultural divide between people on the continent.

But is the divide more than a political and cultural one? Is there a deeper difference among the people of Europe or those of European ancestry than whether Germans have a firmer handshake or are more punctual, or which nationality prefers a kielbasa to köttbulla?

There may be, and those differences can be seen in people’s DNA.

Although all humans are over 99 percent identical genetically, even in the tight geographic confines of Europe there is enough genetic variation that 23andMe researchers can use it to determine from where in Europe a person, or a person’s ancestors, came.

Using principal component analysis (PCA) and linear regression — statistical tools for processing and visualizing large, complex datasets — researchers at 23andMe analyzed genetic data from 3,000 customers who all had four grandparents from the same country of origin. When the results of the analysis are plotted on a two-dimensional graph, individuals of similar ancestry cluster together, and those clusters correspond closely to the geographic locations of the countries of Europe. Researchers at UCLA and the University of Chicago have found similar results.

In that research and the work at 23andMe the clustering shows that populations within Europe have evolved distinct genetic characteristics. Another team took a similar approach to map the genetic differences in East Asia.

This is more than just a parlor trick for data scientists. These maps illustrate that Europeans and people of European ancestry are not homogenous but are in fact they are genetically diverse. Those differences also manifest themselves in other ways — from physical traits such as eye color, to propensities toward certain diseases, and even social and cultural characteristics.

By comparing the ancestry inferred from their genetics to survey responses, 23andMe scientists have identified a number of physical traits associated with a person’s ancestral origin in Europe. In some cases what researchers found is very intuitive — people with Northern European ancestry are more likely to have blue eyes and blond hair, while the hair and eyes of people with Southern European ancestry are more likely brown.

Other associations were more surprising. For instance, 23andMe researchers found that a number of social and cultural traits were strongly associated with a person’s predicted genetic ancestry of origin in Europe. A self-reported diagnosis of alcoholism was more common than average among people of predicted Irish ancestry for instance, while people with predicted Balkan ancestry were more likely to describe themselves as extraverts.

And then there were more serious associations between predicted genetic ancestry and certain diseases. Using data from thousands of 23andMe customers of European descent, our researchers found that ancestry may be important in determining the risks for Parkinson’s disease and for basal cell carcinoma, the most common type of skin cancer. Among 23andMe customers with European ancestry our researchers found that those diseases were more common among those with ancestry from western and northwestern countries in Europe.

All of these associations and others that we found beg many questions. First, do they reflect actual traits among people of different European ancestry or are they simply a reflection of cultural stereotypes among 23andMe customers?  More intriguing is the question of the extent to which these traits are truly influenced by genetics.

While the statistical correlations in the data are strong, we still don’t have a complete picture of why these traits appear to separate according to ancestry. Associations, of course, do not imply causation, so what exactly is going on biologically remains an open question.

See our gallery of Research Findings for PCA plots of ancestry and eye color, socio-cultural traits, and disease risk in Europeans.






  • Ponto

    I guess it depends on whether you are European or Colonial in your viewpoint about the differences between Europeans. I am European so I see less differences than you as a Colonial. For instance, most Europeans view Colonials pretty much the same way whether the Europeans have blue eyes or black hair or speak German or Greek.

    The debt situation in the E.U has more to do with greed, self interest, and wanting people to solve their own problems rather than expecting handouts. Money problems and differences divides families and causes relationship breakups. Europeans are no different there than other humans.

    We all know that the centre of blondness and blue eyes is on the east side of the Baltic Sea. It is not news. I am sure Von Linne and Blumenbach could see that in their by-gone days, long before Darwin or Rosalind Franklin’s X-ray of dna given to Crick and Watson.

    I am more interested in the fact that non Europeans are in the Europe map, Syrians, Lebanese, Moroccans, Egyptians.. Obviously the claim that Europeans can be placed into their countries of origins based on having grandparents from the same country and ethnic group has flaws.

    I think I am the person represented by MT. The placement amongst the Italians is okay but I am not Italian, nor have Italian ancestry for hundreds of years.

  • Sean

    It would be cool if you posted the r-code you used to make the graphs publicly so people could put themselves in using data downloaded from your service.

    • http://23andme.com Shwu

      Hi Sean,

      That’s a great idea; unfortunately the code is dependent on a number of software modules so releasing it as a stand-alone package is not really feasible. We are, however, considering potentially developing these and other analyses into new 23andMe features!

  • Theodora Devereux

    It might be interesting to look at genetic mutations like lactose tolerance in your database. Or is that too early to see differences among Europeans.

    Another mutation of interest might be one like Leiden factor 5 that leads to thrombosis. Was it first identified in Leiden in the Netherlands? Or maybe the discovery was coincidental to a particular region?

    • http://23andme.com Shwu

      Hi Theodora,

      We certainly do see interesting associations between genetic ancestry and other traits and conditions — these are just a few of the strongest ones — and may post more of these in the future. Regarding the factor V Leiden mutation, it was first discovered in Leiden in the Netherlands, but the mutation itself is distributed across populations of European descent at a frequency of about 5%. It is less common in Hispanic and African descent populations and very rare in East Asians.

  • Davidski

    Hi,

    Can we find out whether we’re on that map, and if so, our positions?

    I’m pretty sure I’m one of the Polish pins on there.

    Which scientist at 23andMe should we pester for that info? :p

    • http://23andme.com Shwu

      @Davidski,

      We’ve been getting some interest from customers about allowing direct interaction with these analyses and seeing their own data on the maps, and we’d love to provide this functionality at some point in the future! At the moment, it is not feasible to provide individual-level information about the data on these plots (our research data is decoupled from customer-identifying data for security reasons), so we would need to develop a full-fledged feature on the website to provide that level of detail and interaction. We’re definitely considering it, but cannot give an exact timeline.

  • Greg

    Caught this in Science. Awesome way to view disease risk around the world. geneworld.stanford.edu.

  • John

    Thanks for such fascinating material. Although I don’t want any personal information (I would not qualify for the map) I am intrigued by the methodology. How are the coordinates determined? What do the country codes designate: ethnicity or country of birth (often the same if four grandparents are so ‘close’ I grant)?

  • Bernard Munos

    This is very interesting work. However, while PCA and regression are valuable data-reduction tools, I think you would have gotten richer insights from running a correspondence analysis (the kind developed by Benzecri in the 1960s, and available from SAS and other software). It would have enabled you to find hidden associations within SNPs and populations, as well as correlations linking SNPs and populations. (For a short summary of the method, see http://www.micheloud.com/FXM/COR/e/index.htm).

  • CW

    This information is so dangerous in the wrong hands. So many assumptions can be used against people –especially for insurance coverage and more. At one company when they did the pre drug testing I found out later they also did testing for predisposition of some diseases. As such, their insurance company would not cover you for more than the minimal amount $2500. Just because you have a factor does not mean you will have an illness.

    I have worked with studying a specific genetic disorder for 7 years and all the presumptions doctors have made — some happen but they are totally misguided as to what happens in adults. In addition, the information they have known since 1994 is not being published by agreement of doctors, the US government, and disease associations because it would be in direct conflict of the disease description written in 1973 before any genome project existed.

    I know of multiple cases of people that have had private genetic testing and the metabolic/genetic doctors will not recognize it. Even though the patients (usually women) have the symptoms as I have put forth to the research groups. It is sad and maddening. It is also tied to research funds as well as insurance coverage for the medication which can cost up to $15K a month and is expected to rise under Obama to $25 or 30K a month…..deaths will occur as people will not be able to afford the medication even if the doctors are willing to recognize the disorder. Gold Tests include biopsies and certain type of genetic tests that are very expensive. One of the tests is between $7K to 10K depending on which lab is used.

    I am afraid that employers may be sneakedly obtaining tests and will use against hiring people even though it is to be illegal. Who wants to hire someone that has the propensity for being a drunk, carcinoma, parkinsons —which is tied to dementia and alztheimers as well as some other medical disorders?

    Finding out this information is going to come at a price of a very sharp two edged sword.

  • Jonas Dovydenas

    Physiognomy, the empirical sorting of physical traits (stereotyping without prejudice) has a long and extensive literature and is a product of centuries of observation. There is a lot of silliness out there, but the core of physiognomy is empirically sound. Surely a program could be written to test the principles of physiognomy. If nothing else, to prove that it is nonsense. Or not. Think of all the generals and statesmen all over the map who share a look. Or, the controversial “criminal type.”

    I applaud and approve of ever larger databases fed through ever more discriminating programs that reveal ever more, invisible for now, connections of the individual human body and mind with the rest of humanity.

    Someone will always object to empirical truths, but such truths cannot be a waste, though they can be wasted, as always.

  • Altorfer

    Please stop to call as Europeans. This sounds as you would see us a one ethnic group which belongs together! We are too different! Not only in language. So also in mentality and lifestyle attitudes! Even when I go over the rhine to Germany(I’m Swiss), it’s like I was on a other planet. The people there are different . An exemple: The sellers in Germany are much more friendly with their costumer than the Swiss sellers. The average Swiss seller has less patience with their costumers than in Germany the german sellers! Generally the Swiss people are pretty more introverted than the Germans!

  • Erin Young

    Is there any possibility that 23andme will add Ehlers Danlos Syndrome to their health profiles? It’s such a devastating disease, especially when undiagnosed or diagnosed incorrectly. My sisters 18 year grandson has finally been diagnosed after years of being treated for Crohn’s disease;he is now in a body brace which does help somewhat with the pain but a lot of the permanent damage might have been avoided with an earlier diagnoses. I do understand that you can’t add every syndrome your customers care about and of course it may be complicated beyond doing but could you please let me know anyway? Is it more common in Europeans?

    • Dani

      This is especially important because so many people have hypermobility (are “double-jointed”) which is increasingly being linked to many other joint and connective tissue conditions including knee problems, spinal issues and low back pain.

      • Kc

        I agree…ehlers should be on the profile. Concerned about this myself!

        • Tracey Miles

          Since we know the genes for most of the forms of EDS it could be done. It would be especially helpful to add the gene for VEDs, the vascular form since it is life threatening and can change how you and your medical professionals approach your care significantly.

    • rica

      Elher’s Danlos testing is very expensive and has a ton of different tests for the type of collagen issues. I would be shocked if they could find a way to do it in this saliva test – and extra special happy! My family has seen specialists and so far three generations have family members with it – and at least five with formal diagnosis and many that cannot afford the doctors to get testing. It would be nice if we could even just get a survey on it to see how the numbers show up. Anything that can be added to include this illness would be greatly appreciated. We have now so far nine in our family that have ordered the kit and look for more results to come in. We could add a lot of information!

      • cmartin

        Ehlors Danlos Syndrome, (EDS) the hypermobile type presents in my family along with postural orthostatic hypotension syndrome (POTS)- (diagnoses made at Mayo Clinic in Rochester)- no specialists on the west coast and mulitiple clinics in Eastern US. I was advised this was because EDS/POTS runs in Ashkenazi Jewish populations which are more prevalent in eastern US. My family reportedly is from Wales and England, looks like we should consider testing too.

        • Louise

          Cmartin Normally it is Familial Dysautonomia (which can be mis-diagnosed as POTS) rather than POTS that can be hereditary in the Ashkenazi Jewish population. If you have Jewish ancestry it might be worth looking in to.

      • AnnMarie

        I was also like to see a test for Ehlers-Danlos Syndrome. I am about 99.9% sure I have it, as well as others in my family. I actually came to this site to see if it was included in your testing. Unfortunately that is what I was most interested in, but it is not there. If it becomes available, drop me an email and I’ll be more than happy to do the testing

        • Rena

          I also checked for EDS testing. Both of my parents died of Abdominal Aortal Aneurisms, and I have the hyper-mobility and auto-immune symptoms. I feel it is essential to know about the future implications for my sons. We are of Eastern European Jewish ancestry, so I am interested to put all the pieces together and get some answers. We need to get this testing onto this fascinating reporting system!

  • J.Taber

    I still can’t tell from what I have read on this website what information one receives on European ancestry. Is it just British Isles, northern Europe, Scand., southern Europe or is it more specific? My sons don’t know their maternal heritage (egg donor babies) and would be interested in finding out. One is colorblind and lactose intolerant, so he is interested in the health information, also. Most of the diagrams on this website are too small and in colors that are difficult to discern. Thanks.

    • ScottH

      J. Taber,
      The Ancestry Composition tells you what percent of your DNA comes from each of 22 populations worldwide. The analysis includes DNA you received from all of your ancestors, on both sides of your family. The results reflect where your ancestors lived 500 years ago, before ocean-crossing ships and airplanes came on the scene.
      Here is a breakdown with the populations we use. They include broad categories and then smaller categories within those broader populations.

      European
      Northern European
      British and Irish
      French and German
      Scandinavian
      Finnish
      Nonspecific Northern European
      Southern European
      Italian
      Sardinian
      Iberian
      Balkan
      Nonspecific Southern European
      Eastern European
      Ashkenazi
      Nonspecific European
      Sub-Saharan African
      East Asian & Native American
      East Asian
      Native American
      Nonspecific East Asian & Native American
      Middle Eastern & North African
      Middle Eastern
      North African
      Nonspecific Middle Eastern & North African
      South Asian
      Oceanian

  • mickcollin

    Why doesn’t everyone do some DNA testing and ‘drill down’ for some accuracy?!

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