From a meta-analysis of 14 genome-wide association study datasets, a team led by researchers from Children's Hospital of Philadelphia found two new loci linked to childhood obesity. As the team reports in Nature Genetics, they examined 2.7 million SNPs at seven loci that had previously been linked to adult body mass index. One new locus is near OLFM4 and the other is within HOXB5. "We see a clear genetic signature to childhood obesity, showing there is more than just an environmental component to this disease," CHOP's Struan Grant tells LiveScience. In their paper, the researchers note that functional characterization of the signals to determine the mechanisms through which they work is still needed.