Improvements in Awareness and Testing Have Led to a Threefold Increase Over 10 Years in the Identification of Monogenic Diabetes in the U.K.
Research design and Methods: UK referrals for genetic testing for monogenic diabetes diagnosed >1y of age from 01/01/1996 to 31/12/2019 were examined. Positive-test rates were compared for referrals reporting involvement of the GDNs/MODY calculator with those that did not.
Results: A diagnosis of monogenic diabetes was confirmed in 3860 individuals, >3-fold higher than 2009 (01/01/1996-28/02/2009; n=1177). Median age at diagnosis in probands was 21y. GDN involvement was reported in 21% of referrals; these referrals had a higher positive-test rate than those without GDN involvement (32% v 23%, p<0.001). MODY calculator usage was indicated on 74% of eligible referrals since 2014; these referrals had a higher positive-test rate than those not using the calculator (33% v 25%, p=0.001). 410 (10.6%) cases were identified through tNGS. Monogenic diabetes prevalence was estimated to be 248 cases/million (double that estimated in 2009 due to increased case-finding).
Conclusions: Since 2009, referral rates and case diagnosis have increased three-fold. This is likely to be the consequence of tNGS, GDN education and the MODY calculator.