Pathogenic variants of MODY-genes in adult patients with early-onset type 2 diabetes

Type 2 diabetes is a complex disease typically occurring in middle-aged and older adults, which is diagnosed when other forms of diabetes can be reasonably excluded. However, due to the marked clinical heterogeneity, the diferential diagnosis of diabetes in adulthood can be challenging. This is especially the case for early-onset type 2 diabetes, which cannot be easily distinguished from monogenic forms of hyperglycemia also occurring at a young age. It has been recently reported that 2.8% of youth (aged < 20 years) with presumed type 2 diabetes carry pathogenic or likely pathogenic (P/LP) variants in genes for maturity-onset diabetes of the young (MODY) [1]. This observation has crucial implications for clinical practice, as these presumed type 2 diabetes patients would beneft from the specifc follow-up and treatment strategies that have been developed for MODY [2]. In light of these fndings, we investigated whether and to which extent adult patients (>18 years) with early-onset (≤35 years of age) type 2 diabetes also carry P/LP variants in MODY genes.