Genome-wide association studies (GWAS) have the potential to localize genetic loci contributing to obesity down to a few 100 kb [5]. In fact, a recent meta-analysis of the adult GIANT Consortium established 32 susceptibility BMI loci [6], several of which were confirmed in French and German children with extreme obesity [7] and European adults with early-onset obesity [8]. Two novel loci near OLFM4 and within HOXB5 were recently reported based on a meta-analysis of 14 pediatric studies of BMI [9]. These pediatric GWAS were confined to BMI and cohorts of European ancestry.
