HNF1A and diabetes mellitus: Increased T2D genetic risk has also been shown to lower the age at diagnosis of patients with monogenic MODY variants, and even within large multigeneration HNF1A MODY families.37 These findings reinforce the idea that T2D risk variants increase the risk of diabetes by acting on the same physiological mechanisms affected by monogenic variants in MODY genes, rather than through completely separate genetic pathways.