23andMe’s new Type 2 Diabetes report* offers customers insight into their likelihood of developing one of the most prevalent, pernicious, and yet preventable health conditions in the United States.
This new report will impact more 23andMe customers than any other Health Predisposition report the company has ever released. In part, this is because the likelihood of developing type 2 diabetes is so high in the general population.
“Diabetes is a significant health issue in the United States that is expected to impact nearly half of the population,” said Anne Wojcicki, CEO and Co-Founder of 23andMe. “When customers learn about their genetic likelihood of developing type 2 diabetes, we believe there is an opportunity to motivate them to change their lifestyle and ultimately to help them prevent the disease.”
What’s a Polygenic Score?
The genes we inherit from our mother and father influence our risk of disease. While that’s pretty straightforward, the role genetics plays is a bit more complicated.
Although there are examples of a single genetic variant in a single gene causing certain conditions, it is often the case that hundreds or even thousands of variants — along with lifestyle and environmental factors — all play a role. And that’s precisely the case with type 2 diabetes.
For 23andMe’s new Type 2 Diabetes report, we created a model that incorporates more than 1,000 genetic variants to calculate a polygenic score for a customer’s likelihood of developing type 2 diabetes.
It’s not the first time we’ve used this method. However, it is the first time we’ve used this kind of polygenic score for a Health Predisposition report. In the past, we’ve used this method to develop our Genetic Weight Report. That report used both genetic data — hundreds of variants associated with BMI — and non-genetic data to calculate a person’s genetic predisposition to weigh more or less than average.
Several other trait reports similarly rely on polygenic scores. For example, 23andMe’s recent reports on Motion Sickness, the ability to Match a Musical Pitch, and estimated Wake Up Time each use hundreds of variants to calculate one’s predisposition toward those traits.
23andMe will continue to use these kinds of polygenic modeled reports to report health predispositions to its customers. We are uniquely positioned to do this because of the data our customers contribute. This in turn allows our researchers to better understand the complex genetic underpinnings of various diseases. We can also then create polygenic models that take into account the cumulative effects of a large number of genetic variants. This allows us to give better estimates of their influence on different health conditions and diseases.
You can learn more about how others are incorporating polygenic modeling to estimate risk by looking at coverage in the Harvard Gazette. That article focuses on research done by scientists at the Broad Institute of MIT, Harvard, and Massachusetts General Hospital. In the summer of 2018 the team published their findings in the journal Nature. The study showed how they created a polygenic model to better estimate for the risk of five different conditions. The conditions included type 2 diabetes, breast cancer, and coronary artery disease.
Rising Rates of Diabetes
In the United States alone a staggering one in three Americans have prediabetes, according to estimates from the U.S. Centers for Disease Control and Prevention. Worse, 90 percent don’t know they have it. The impact is even greater among certain ethnicities. For example, Hispanics have the highest rates of diabetes with about 20 percent having the condition.
Worldwide, as lifestyle and diets are changing, the prevalence is also increasing. Beyond the very real human costs are the healthcare costs for treating the condition. In the United States estimates for the costs of treating diabetes are more than $327 billion per year, according to the American Diabetes Association.
Despite the alarming statistics, there’s reason to be optimistic. Type 2 diabetes is one condition that can be prevented or delayed with lifestyle and diet changes. Genetics, family history, ethnicity, and age all contribute to the likelihood for developing type 2 diabetes. But type 2 diabetes is preventable. In many cases the likelihood can be lessened with a healthier diet and exercise. That’s where this report could help, by raising awareness among customers about their likelihood of developing the condition. There is some evidence that people do make positive changes to their diet and exercise more after getting genetic testing, according to 2017 study led by researchers at Brigham and Women’s Hospital, Broad Institute and Harvard Medical School.
The New Report and the Genetics of Type 2 Diabetes
We hope that 23andMe’s new Type 2 Diabetes report will raise awareness about diabetes. The report also informs customers of the potential of making healthy lifestyle changes to lower one’s likelihood of developing type 2 diabetes. We’re excited by the potential that this report has for making a difference in people’s lives, but it’s significant for another reason as well.
This report is built using real-world data from more than 2.5 million 23andMe customers who have opted into research. Some of those customers have the condition and others do not. Together the data from those cusomters have allowed our product scientists to create what’s called a polygenic score. To asses an individuals likelihood of developing type 2 diabetes, our team created a model that takes into account more than a thousand genetic variants.
Research has shown that type 2 diabetes is partially impacted by many genetics. Many genetic variants each individually have a tiny impact on the likelihood of developing it. The Type 2 Diabetes report calculates the combined effects of more than 1,000 of these variants. These variants, known as single nucleotide polymorphisms ( SNPs) are variations in DNA sequence at particular locations in the genome. The calculation uses all these variants to arrive at a polygenic score. The report can help customers learn how their genetics, influence the likelihood of developing type 2 diabetes. It also looks at other factors such as weight, age and lifestyle. In addition, the report also suggests actions customers can take to lower that likelihood.
Unlike other 23andMe health reports we developed and validated the Type 2 Diabetes report completely on 23andMe research data. The report also underwent scientific review by our team of scientists, as well as reviews by our Medical Affairs and Regulatory teams. In addition, to create this report 23andMe relied on the expertise and knowledge of external experts. We included input from other scientific and medical professionals who are familiar with polygenic scores and the condition itself.
To learn more about the science behind 23andMe’s new Type 2 Diabetes report see our white paper.
*Note: The 23andMe Type 2 Diabetes report is based on 23andMe research and incorporates more than 1,000 genetic variants to provide information on the likelihood of developing type 2 diabetes. The report does not account for lifestyle or family history and has not been reviewed by the US Food and Drug Administration. Visit www.23andme.com/topics/health-predispositions/type-2-diabetes for additional important information.