MC3R and Syndromic obesity: Deletion of the mouse Mc3r gene causes an obesity syndrome (Butler et al. 2000; Chen et al. 2000), and some reports indicate that MC3R polymorphisms that impact on signaling may be associated with increased risk of childhood obesity (Feng et al. 2005; Mencarelli et al. 2011; Savastano et al. 2009; Zegers et al. 2011).