23andMe Tests New Ancestry Breakdown in Central and South Asia

May 12, 2019
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article by Nicky Hoseck author
23andMe is one the largest and most active home DNA testing companies, performing extensive research into genetics in an effort to more accurately understand both ethnicity and health. Although 23andMe has come in for some heavy criticism over their use of consumer data for research purposes, the benefits of it are difficult to dispute.

Not only has 23andMe’s research led to a better understanding of the role our genetic makeup plays in the development of diseases like type-2 diabetes, but recent developments mean it can also shed light on individuals with Central and South Asian ethnicity.

Central and South Asian Ancestry

In the past, South Asian ethnicity was all lumped together, giving people with ancestors in the region little idea of their true origins. Take, for example, the story of Michael Kim from Chicago who purchased a home ancestry test from Ancestry.com, only to be told he was 100% Asian. Kim already knew he was Korean, so this probably wasn’t the revelation he was hoping for! The new test from 23andMe, however, provides much more detail, breaking Central and South Asia ethnicity down into seven different populations:

  1. Central Asian includes people of Afghan, Pashtun, Pakistani, and Uzbek descent among others
  2. Bangladeshi and Northeast Indian
  3. Central and Southern Indian
  4. Gujarati Patel
  5. Kannadiga, Tamil, Telugu and Sri Lankan
  6. Malayali
  7. North Indian and South Pakistani, including people from Burusho, Kashmiri, Odia, and Uttar Pradesh, among others.

For home DNA ancestry test users, this means a much clearer and more precise understanding of their origins and the culture and lifestyles of their ancestors.

How Did 23andMe Gather this Data?

The best DNA testing kits use granular genetic ancestry prediction models to identify an individual’s genetic makeup. The easiest way to explain this is to compare the human population to a beach full of sand where each grain is unique but shares similarities with some other grains. Say, for example, you then study a collection of grains of sand that all share the same silicon dioxide content. In doing so, researchers would be able to potentially identify other similarities shared by those same grains.

Furthermore, grains with a high silicon dioxide content probably come from the same geographical region, making it easier to then establish the environmental origin of other grains of sand with similar mineral composition.

In a similar way, companies like 23andMe have compared the DNA of thousands of people and established ethnic clusters based on shared DNA trends, language, and ethnicity. It is only by combining the information extracted from DNA samples with data from those being tested that these relationships can be identified and explored.

In addition to using publicly available databases, like the Human Genome Diversity Project and 1000 Genomes Project, 23andMe made use of home DNA test consumers who consented to their information being used for research purposes. By analyzing the DNA samples submitted by 23andMe customers who said that all four of their grandparents came from an area in Central or South Asia, the company was able to create a reference group which formed the basis for further research.

Using genetic clustering techniques, 23andMe was able to identify certain features that distinguished one ethnic group from another.

What Surprises Did the Research Reveal?

As far as most of us are concerned, Gujarat is a region of India situated to the north of Mumbai on the border of Pakistan which is famous for its lions and sacred sites. What 23andMe’s research revealed, however, was that not all those who considered themselves Gujarati have ancestors from Gujarat. As 23andMe dug deeper, so a distinct cluster emerged – a different group of Gujaratis from a different region of western India.

Most descendants from this group of Gujaratis share the surname Patel and further research by 23andMe revealed that due to marriage practices in the region, this group of people developed a distinctive DNA unique to their small endogamous community. Endogamy is the practice of marrying within a small community of people, causing a distinct genetic population to emerge.

Another genetic anomaly to emerge from 23andMe’s Asian ethnicity research was the distinctive DNA of individuals descended from the residents of Kerala. Known as “God’s own country”, Kerala is situated in the southwest of India, and is polygenetic, meaning it has influences from various different races and ethnic groups. Nevertheless, people descended from Kerala residents have DNA that clearly distinguishes them from those descended from inhabitants of the neighboring states of Tamil Mudu and Karnataka.

The precise ethnicity and genetic makeup of the people of Kerala has been a point of contention for some years, with some saying the population is originated from the Ezhavas, others the Negritos and still others, the Dravidians. One of the distinguishing factors within their genes, however, is the similarity between the DNA of a Kerala resident and that of a European, which sets them apart from the Pakistani, Tamil and Telugu ethnicities.

While the work on these distinctions and what they actually mean for those with ancestors in these areas is far from over, 23andMe is nonetheless giving people of Central and South Asian ancestry a much clearer idea of who they are and where they come from.

Research Continues

23andMe’s exploration of ancestry and ethnicity is far from over and the company invites users to take part in its beta testing program. In exchange for getting the first option on the company’s latest features, customers are asked to give feedback about any issues they have during their 23andMe experience. It is from consumers participating in this type of research that 23andMe has been able to get a better understanding of the different ethnic groups present in Central and South Asia over the years.

Although 23andMe’s ancestry DNA tests for people descended from the South and Central areas of Asia are now much more accurate and specific, there is still more work to be done. 23andMe are calling for home DNA test users to volunteer information about their Central and Southern Indian ethnicity in particular. While 23andMe has identified this group as being genetically distinct, they need further evidence to prove precisely why and how this distinction emerged.

It’s not only 23andMe that have been investigating the genetic origins of people in Central and South Asia, however, and last year, researchers revealed that the genetic ancestry of people from these regions showed repetitive intermingling between Middle Eastern farmers, local hunter-gatherers, and herders from Central Asia. Not only is this important in terms of our understanding of the genetic makeup of people from this area, but it also promises a possible resolution to a long-running dispute.

The Aryan Invasion Theory may sound both racist and improbable, suggesting that a race of blue-eyed, blonde-haired people rode into India on horseback, conquering everyone along the way, but DNA suggests that it did, in fact, take place in the form of a mass migration of people from the Eurasian Steppe. According to the author of a different study, Professor Martin P. Richards, recent DNA research has produced “very powerful evidence for a substantial Bronze Age migration from central Asia that most likely brought Indo-European speakers to India”.

Not only is this something of an eye-opener for the political and religious leaders who have been keen to contest the Aryan Invasion Theory for understandable reasons, but it also gives individuals of Central and South Asian descent a clearer idea of where their ancestors came from and what kind of lives they lived.

Where Will 23andMe Go Next?

Central and Southern Asia isn’t the only under-studied and poorly understood population in the world and 23andMe is now planning to focus on the genetic roots of its African American and Latino customers. At the beginning of the year, 23andMe was calling for ancestry researchers to join them in the exploration and analysis of specific genetics shared by people of African, East and South Asian, Middle Eastern and Latino ancestry.

Although 23andMe hasn’t specified the precise nature of this research, similar projects have produced valuable information relating to the connection between genetics, obesity and height, and the genetic reasons for the heightened risk of uterine fibroids in women of African American origin, rather than those of European American descent.

Should I Do a Home DNA Test?

23andMe’s new ancestry breakdown for descendants of Central and South Asian ethnicities proves that genetic testing can have some useful benefits, both for individuals trying to understand their origins, and for entire cultures trying to get to grips with where they came from. In addition to shedding light on the movement of different people throughout history, DNA testing is also revealing important genetic trends that could help medical experts identify and treat certain diseases more effectively.

With home DNA testing still in its infancy, not all tests produce the accurate results 23andMe nor its customers would like to see and 23andMe’s tests for the BRCA1 and BRCA2 genes, which are associated with breast cancer, won’t necessarily give users accurate information about their genetic predisposition to the disease.  According to The New York Times, nearly 90% of participants with a BRCA mutation would have had negative test results in the 23andMe BRCA test despite actually carrying a genetic mutation associated with the disease. The reason being that the test focuses on only three of the 1,000 known BRCA mutations. According to a rival company, that means that, out of nearly 5,000 people with BRCA1 or BRCA2 mutations, only around 12% would have tested positive with 23andMe.

To say that home DNA testing is still in its nascent form would be an understatement and there is still much to learn about our genetics and what they really tell us about who we, where we came from, and what our children may look like.

While people who were previously lumped together as Central Asian can now have a much more detailed idea of where their ancestors came from and the kind of lives they led, there are still many things a home DNA test can’t reveal.

However, if you want to get to know yourself better or start to understand what your genetics say about your ancestors and your own origins, a home DNA test is a great place to start. If you’re worried about what diseases you may pass onto your children, a DNA health test can also be revealing, but if you really want to get to the bottom of what your genes are telling you about your health, you’d be better off speaking to your GP or another medical expert.

Conclusion

As research continues to improve the results available from home DNA tests, so more people will be using this method to find out more about who they are and where they came from. Research is also improving the accuracy of health DNA tests, although some reports are still limited.

That 23andMe is involved in some beneficial and ground-breaking genetic research is undeniable and recent findings regarding the diversity of ethnic influences on the DNA of people descended from Central and South Asia indicates much more can be uncovered by using genetic testing and technology.

Although home DNA health tests may not yet produce results that are 100% accurate, 23andMe’s commitment to research and pursuit of scientific knowledge promises to yield yet more information about how genetics not only inform us but also influence our day-to-day choices and habits.