The Brain-Derived Neurotrophic Factor Gene
Brain-derived neurotrophic factor (BDNF) regulates growth and is centrally involved in appetite regulation, with decreased BDNF function associated with increased food intake (Culbert, Slane, & Klump, 2008). Reduced BDNF levels have been found in AN and BN (Favaro, Monteleone, Santonastaso, & Maj, 2008). An allele of the BDNF gene, namely, the Met allele of the Val66Met polymorphism, reduces secretion of BDNF (Egan et al., 2003), and carrying the Met allele has been found to be significantly associated with both AN (Ribases et al., 2004; Rybakowski et al., 2007) and BN (Ribases et al., 2004). In addition, a meta-analysis (Gratacos et al., 2007) supported an association between carrying the Met allele of the BDNF gene and eating disorders broadly defined (including ANBP, BN, and disorders in the DSM-IV category “eating disorder not otherwise specified”). However, as with findings for the A allele of the 5-HT2A gene, not all studies have supported an association between the Met allele and eating disorders (Gratacos et al., 2007).
