The symptoms of hypoglycemia lessen with increasing duration of diabetes. There is a progressive loss of glucagon response to insulin-induced hypoglycemia over the 12 months after diabetes onset and it is lost in most people with T1D by 5 years (17, 18). Thus, half of adult patients with long-term diabetes have experienced unawareness of hypoglycemia, leading to severe episodes (19), while no data are available for children and adolescents. Here, GCG is linked to diabetes mellitus.