HNF1A and diabetes mellitus: This is likely to reflect several factors: first, four of the 13 patients were pregnant or attempting to conceive, which affected the management options available; second, molecular diagnoses in this cohort in many cases followed many years after onset of diabetes, and in the longer term many HNF1A and HNF4A patients do progress to requiring insulin; and third, intensive education and support is required to transfer patients off insulin, and this is complicated by higher rates of patient mobility, language barriers and low socioeconomic status in urban diabetes centers.