BDNF and obesity due to melanocortin 4 receptor deficiency: Patients with WAGR syndrome (Wilm’s tumor, aniridia, genitourinary anomalies and mental retardation, OMIM 194072) with a heterozygous 11p14 deletion including the BDNF gene suffer all from childhood onset obesity, while WAGR syndrome patients without genetic anomalies including the BDNF gene have normal prevalence of obesity [33].