Background and Aims: Maturity Onset Diabetes of the Young (MODY) is a group of uncommon monogenic forms of diabetes. Since the management and prognosis of MODY can differ from other diabetes types, detection is important but genotyping is expensive and not widely available. A clinical prediction tool developed recently in the UK generates a probability of MODY which can be used to select patients for genotyping. Our aim was to determine its validity in an Australian community setting.

Research Design and Methods: The Fremantle Diabetes Study Phase II (FDS2) is an observational cohort study that recruited 1732 representative patients from a postcode-defined catchment area during 2008–2011. The MODY tool was applied to the FDS2 patients diagnosed at age <35 years using, for comparison with type 1, HbA_1c, parental diabetes, sex and age at diagnosis, and, for type 2, the same variables plus BMI and oral hypoglycaemic/insulin treatment.

Results: Of 204 of the 206 patients aged < 35 years at diagnosis who had sufficient data for the MODY algorithm, 25 (12.3%) were defined as having MODY using the 25% cut-off adjusted for pre-test MODY probability. As the MODY tool was developed for Anglo-Celts, we further limited the analysis to the 157 Europid patients in this subset and 12 (7.6%) were identified as likely MODY. Of these, two already have genetically confirmed MODY, one has been diagnosed clinically with MODY, and one (diagnosed soon after birth) has a confirmed sulphonylurea receptor mutation. Of the remainder, four are managed as type 1 and four as type 2 diabetes. The full genotyping data will be presented.

Conclusion:  The MODY tool successfully identified the two Europid patients with known MODY in the FDS2 cohort. Further genetic analysis of probable cases will confirm whether or not it has cost-effective utility in an Australian context.