BDNF and obesity due to melanocortin 4 receptor deficiency: Furthermore, large-scale genome-wide association studies link a common single nucleotide polymorphism in the Bdnf gene, rs6265, to human obesity (Hotta et al., 2009; Thorleifsson et al., 2009), and rs6265 has been shown to be associated with human eating disorders (Ribases et al., 2004; Gratacos et al., 2007).