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, but 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, which 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 to estimate a customer’s genetic predisposition toward certain conditions or traits. 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 is hoping to continue to use these kinds of polygenic modeled reports to report health predispositions to its customers. 23andMe is 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. And we can then create polygenic models that take into account the cumulative effects of a large number of genetic variants to better estimate 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 of 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 showing how they created a polygenic model to better estimate for the risk of five different conditions including type 2 diabetes, breast cancer, and coronary artery disease.
Rising Rates of Diabetes
In the United States alone, where rates of obesity have ratcheted up in recent decades, 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. And 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. While genetics, family history, ethnicity, and age all contribute to the likelihood for developing type 2 diabetes, in many cases the 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 from a 2017 study led by researchers at Brigham and Women’s Hospital, Broad Institute and Harvard Medical School that consumers do make positive changes to diet and exercise after getting results from genetic testing.
The New Report
We hope that 23andMe’s new Type 2 Diabetes report will help raise awareness about diabetes, as well as the potential to make healthy lifestyle changes to lower one’s likelihood and potentially prevent type 2 diabetes from occurring in the first place. 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, but together they have allowed our product scientists to create a what’s called a polygenic score. To create this score, our team created a model that takes into account more than a thousand genetic variants to assess an individual’s likelihood of developing type 2 diabetes.
Research has shown that type 2 diabetes is partially impacted by many genetic variants that 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 — known as single nucleotide polymorphisms, or SNPs, which are variations in DNA sequence at particular locations in the genome — to arrive at a polygenic score. The report can help customers learn how their genetics, along with other factors such as their weight, age and lifestyle, may influence the likelihood of developing type 2 diabetes, as well as actions they can take to lower that likelihood.
The Type 2 Diabetes report is different from other 23andMe health reports because it was developed and validated completely on 23andMe research data. The report also underwent scientific review by our team of scientists, as well as review by our Medical Affairs and Regulatory teams. In addition, 23andMe also relied on the expertise and knowledge of external experts, and 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.