Another X-linked gene is O-GlcNAc transferase (OGT), although its functions on body weight balance appears to be site specific, with OGT in orexigenic agouti-related peptide (AgRP) neurons promoting weight gain (Ruan et al., 2014) while OGT in anorexigenic PVH neurons prevent overeating and obesity (Lagerlof et al., 2016). This evidence concerns the gene AGRP and obesity disorder.