2001). However, several models of TH deficiency, including the Dio3−/− model, exhibit growth retardation in the embryonic and early post-natal period (Gothe et al. 1999, Hernandez et al. 2006) when growth and IGF1 secretion are known to be GH independent (Lupu et al. 2001). This evidence concerns the gene IGF1 and hyperinsulinemic hypoglycemia, familial, 4.