We have previously shown that fibrin clot properties, in particular fibrin clot lysis, predicts vascular risk and clinical outcome in individuals with diabetes.8,9 In this pilot study we hypothesise that clot structure is altered in individuals with the commonest form of MODY, due to pathogenic variants in HNF1A, which in turn may be one mechanism for the enhanced risk of vascular complications in this population. Here, HNF1A is linked to diabetes mellitus.