Okubo et al. reported two children with an abnormal growth were related to IGF1R. The first child with a growth retardation and hypoglycemia had only one copy of IGF1R while the second with overgrowth showed three copies of IGF1R. This suggests that loss of expression of IGF1R leads to growth retardation and over expression leads to overgrowth [15]. The gene discussed is IGF1R; the disease is Hypoglycemia.