Commercial DNA-analysing company 23andMe is looking to launch a new DNA assessment to help individuals discover their risk of developing type 2 diabetes. Several million customers will receive the information over the coming weeks.

The company’s diabetes report will be based on a polygenic risk score which calculates the chance that someone will contract the disease by looking at their genome. It will examine information at 1,244 individual locations in a person’s genome, each of which has a small bearing on overall diabetes risk.

Around 20% of customers will have an increased risk of getting diabetes, with roughly the other 80% having an average risk. Only those who have a high risk of getting diabetes will be given exact odds of developing it.

Experts have warned that such polygenic scores are not highly accurate as of yet, and have no proven health benefits. It is particularly unreliable regarding diabetes, which is shaped largely by age, diet and weight. Beyond that, 23andMe’s test has been tested predominantly on white people, who make up much of its database, and so performs less well on other races and populations.