FTO and obesity due to melanocortin 4 receptor deficiency: In addition, the effect size of FTO rs9939609 on the risk of obesity observed in our study was similar to the effects reported by Frayling et al. in UK children aged 11 years (OR per-A allele = 1.35, 95% CI 1.14-1.61) [3] and Hinney et al. in German children and adolescents (OR = 1.57, 95% CI 1.30-1.90) [27], although the minor allele frequency of rs9939609 SNP was lower in Chinese than in European populations.