Dominant mutations of the HNF4A or HNF1A transcription factor genes cause HI, at least in part, due to decreased expression of the KATP-channel; the hyperinsulinism usually resolves during infancy, but may evolve into diabetes in the second or third decade of life (MODY1 and MODY3), so affected infants frequently have a history of type 2 diabetes in a parent or other relative (30). Here, HNF4A is linked to diabetes mellitus.