Before trekking, T1DM patients should take into account many other potential problems, such as the effect of delayed absorption of carbohydrate at mealtime, dehydration, high levels of exertion, psychological stress, suppressed appetite, risk of insulin freezing, decreased effectiveness of glucagon owing to possible body glycogen store depletion, unintentional insulin delivery from the insulin pump due to reduced barometric pressure, and many others [1, 3, 5]. The gene discussed is INS; the disease is type 1 diabetes mellitus.