Ahead of our trip to Asia this year, we turned to 23andMe for some home truths about our roots
I never felt exotic growing up. I was one of eight Bangladeshi children in a street full of Bangladeshi residents in an area full of Bangladeshi immigrants.
In my home borough of Tower Hamlets, Bangladeshis account for almost one third of the population – considerably larger than the proportion across London (3%) or England (<1%). In fact, Tower Hamlets has the largest Bangladeshi population in the whole of England.
As an adult, I went to work at places like Accenture (where I met zero Bangladeshis) and Penguin Random House (where I met zero Bangladeshis) before packing it all in to travel the world (where I met zero Bangladeshis). Suddenly, I found that people were exceedingly interested in my roots. Suddenly, being Bangladeshi was a point of curiosity, a topic of conversation.
In an effort to answer that question definitively – and to try and get Peter an interesting origin story – we tried the 23andMe DNA testing kit before our trip to Asia this year. I was keen to see if there was any East Asian in my family as I’m frequently asked if I have any Thai or Singaporean or Malaysian in my ‘mix’. I’ve always been sure that the answer is no.
The 23andMe DNA testing kit revealed that I’m 93% South Asian (yup), 5% East Asian (wat?) and 2% Unassigned (huh). This, as I understood it, means there may be an East Asian ancestor four or five generations back in my family. I wondered just how far the test could look without losing accuracy.
Jhulianna Cintron, a 23andMe ancestry expert, explains that “the Ancestry Composition report goes back 5-10 generations. Each of those generations account for approximately 25 years so the total years within the report can be up to 250 years.”
A span of 250 years is clearly impressive but what about the ‘Unassigned’ DNA? Why can’t it be categorised?
Jhulianna says: “There are certain pieces of DNA that can be found all over a certain region and not outside of that region. Anything that you see as broadly European, broadly western European, those can be found just in those regions. Any pieces of DNA that can be found in multiple regions – so Europe, Asia, western Asia, Middle East – are going to be labelled as ‘Unassigned’. We’re just not able to confidently assign them to a particular reference population so instead of just arbitrarily assigning it, those are going to be your ‘Unassigned’ label.”
My DNA testing had thrown up some interesting information about my ancestry – but what of Peter? Did he gain the story he craved?
Sadly, Peter is 99.9% European and only 0.1% Unassigned. I pointed out that his European quotient includes 6% Scandinavian after which he perked up and started calling himself a Viking.
The 23andMe DNA testing also offered insight into general Traits. Apparently, I have <1% chance of having red hair and a 10% chance of being blonde. More dubiously, I’m a ‘Likely Sprinter’ and have ‘Decreased’ pain sensitivity. Anyone who’s run with me knows that’s just not true. With this in mind, I wondered if DNA testing and, more specifically, tracing ancestry are really just forms of genetic astrology as some have accused.
Jhulianna says: “With regards to the Ancestry Composition report, we look at a lot of data [including] private datasets and public datasets. We’re looking at a genetically similar group so it’s not like we’re just assigning you an ancestry based on what we think you might be, it’s because that is actually what is in your DNA; you’re genetically similar to the reference population.”
She adds: “We like looking at your DNA as little cars on a train. We’re looking at specific windows within your DNA and then we compare those windows to the windows of known datasets and that’s how we assign you to a reference population. We’re very confident in those results.”
In terms of confidence levels, 23andMe offer three flavours. Speculative is the most granular but comes at a 51% confidence level, Standard is pegged to 75%, while Conservative offers 95% confidence.
Jhulianna explains: “Any ancestry that ‘disappears’ when you move to the Standard or the Conservative is going to move to a more general category. It’s not disappearing from your results completely, it’s just going to the more broad category.”
Confidence is key, especially in the Genetic Risk Factors and Inherited Conditions sections of the Health & Ancestry test. This explains why our results didn’t include heart disease and diabetes which exist in my family, nor cancer which exists in Peter’s.
Stacey Detweiler, 23andMe medical affairs associate and genetic counsellor, tells us: “We don’t have a report on cancer, heart disease and diabetes as a whole. There are so many different types of heart disease and the same thing with cancer so we don’t think there’s just one or two genes that influence that risk overall. We think there’s probably a lot of genes that play a role and a lot of environmental and lifestyle choices so at this point in time, we don’t have enough information to be able to do a genetic test result and give you something actionable.”
Some may say that DNA testing, particularly in relation to health, is risky as you might stumble across something you don’t wish to know. Perhaps customers should be equally warned that you may find nothing of remark at all. Like Peter, your ancestry may be less exotic than you’d hoped.
Although, maybe that’s unfair. Peter’s ‘Unassigned’ ancestry does include the possibility that he’s <0.1% Yakut so he’s holding firmly onto that.