As explained above, mice with paternal disruption of Gnas exon 2 have severe defects that are similar to those seen in mice with paternal disruption of Gnasxl [67], including reduced adiposity, which is not seen in patients with paternally inherited inactivating Gsα mutations (PPHP); these patients are typically overweight. This evidence concerns the gene GNAS and pseudopseudohypoparathyroidism.