Genetic risk score identifies nearly one in five MODY referrals with hidden type 1 diabetes

A new study published in Diabetes Care reveals that incorporating a genetic risk score into standard testing for a genetic form of diabetes affecting young people could identify hidden type 1 diabetes in approximately 1 in 5 patients with a negative genetic test result. Researchers from the University of Exeter analyzed over 1,100 patients being treated with insulin and referred for genetic testing for maturity-onset diabetes of the young (MODY), a condition typically diagnosed before age 25 with a strong inherited component.

While 80% of patients had a negative test, indicating an uncertain cause for their diabetes, the researchers found that applying a type 1 genetic risk score to the negative test results identified 16% (around 180 patients) with atypical type 1 diabetes. The genetic risk score, developed at Exeter, is a cost-effective method that considers all known genetic risk factors for type 1 diabetes.

By integrating this score into routine testing, genetic laboratories can provide a diagnosis of type 1 diabetes for patients whose MODY test previously returned without explanation. This approach, now adopted as part of NHS testing, has the potential to reduce diagnostic uncertainty, limit further expensive testing, and provide patients with clear answers about their diabetes type, ultimately guiding more effective treatment and management.